From e5161f397e2d5cbe9c6967b9d466dade2f42d2a8 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Wed, 28 Aug 2024 17:43:12 -0700
Subject: [PATCH 01/13] BlockScriptSerialization: Add block library and
 instantiation

This changes BlockScriptSerialization to manage its own list of
available block definitions and instantiate them, replacing the existing
functionality that was in CategoryFactory and ui/util.gd. The change
makes it easier to understand the state of the block catalog, because it
is a component of the block script itself instead of spread across
different static variables.

In addition, this adds a singleton block editor context, which keeps
track of the current block code node and its associated block script.
The context object provides enough information for different UI
components to update automatically when the block script changes.

https://phabricator.endlessm.com/T35564
---
 addons/block_code/block_code_plugin.gd        |   7 +-
 .../code_generation/blocks_catalog.gd         |  36 ---
 .../block_code/drag_manager/drag_manager.gd   |   8 +-
 .../block_script_serialization.gd             | 217 ++++++++++++++++--
 .../ui/block_canvas/block_canvas.gd           |  28 ++-
 addons/block_code/ui/block_editor_context.gd  |  33 +++
 addons/block_code/ui/blocks/block/block.gd    |   3 -
 .../parameter_output/parameter_output.gd      |  22 +-
 addons/block_code/ui/main_panel.gd            |  77 ++++---
 .../ui/picker/categories/block_category.gd    |  13 +-
 .../categories/block_category_display.gd      |  11 +-
 .../ui/picker/categories/category_factory.gd  | 107 +--------
 .../create_variable_dialog.gd                 |  15 +-
 addons/block_code/ui/picker/picker.gd         |  63 +++--
 addons/block_code/ui/title_bar/title_bar.gd   |  16 +-
 addons/block_code/ui/util.gd                  |  43 ----
 tests/test_category_factory.gd                |  29 ++-
 tests/test_code_generation.gd                 |   5 +-
 18 files changed, 396 insertions(+), 337 deletions(-)
 create mode 100644 addons/block_code/ui/block_editor_context.gd

diff --git a/addons/block_code/block_code_plugin.gd b/addons/block_code/block_code_plugin.gd
index c4370d6b..96b9b7ab 100644
--- a/addons/block_code/block_code_plugin.gd
+++ b/addons/block_code/block_code_plugin.gd
@@ -1,5 +1,6 @@
 @tool
 extends EditorPlugin
+
 const MainPanelScene := preload("res://addons/block_code/ui/main_panel.tscn")
 const MainPanel = preload("res://addons/block_code/ui/main_panel.gd")
 const Types = preload("res://addons/block_code/types/types.gd")
@@ -93,16 +94,10 @@ func _exit_tree():
 
 
 func _ready():
-	connect("scene_changed", _on_scene_changed)
 	editor_inspector.connect("edited_object_changed", _on_editor_inspector_edited_object_changed)
-	_on_scene_changed(EditorInterface.get_edited_scene_root())
 	_on_editor_inspector_edited_object_changed()
 
 
-func _on_scene_changed(scene_root: Node):
-	main_panel.switch_scene(scene_root)
-
-
 func _on_editor_inspector_edited_object_changed():
 	var edited_object = editor_inspector.get_edited_object()
 	#var edited_node = edited_object as Node
diff --git a/addons/block_code/code_generation/blocks_catalog.gd b/addons/block_code/code_generation/blocks_catalog.gd
index f1fd8e62..6fd38e84 100644
--- a/addons/block_code/code_generation/blocks_catalog.gd
+++ b/addons/block_code/code_generation/blocks_catalog.gd
@@ -96,40 +96,6 @@ static func _setup_definitions_from_files():
 		_by_class_name[target][block_definition.name] = block_definition
 
 
-static func _add_output_definitions(definitions: Array[BlockDefinition]):
-	# Capture things of format [test]
-	var _output_regex := RegEx.create_from_string("\\[([^\\]]+)\\]")
-
-	for definition in definitions:
-		if definition.type != Types.BlockType.ENTRY:
-			continue
-
-		for reg_match in _output_regex.search_all(definition.display_template):
-			var parts := reg_match.get_string(1).split(": ")
-			var param_name := parts[0]
-			var param_type: Variant.Type = Types.STRING_TO_VARIANT_TYPE[parts[1]]
-
-			var output_def := BlockDefinition.new()
-			output_def.name = &"%s_%s" % [definition.name, param_name]
-			output_def.target_node_class = definition.target_node_class
-			output_def.category = definition.category
-			output_def.type = Types.BlockType.VALUE
-			output_def.variant_type = param_type
-			output_def.display_template = param_name
-			output_def.code_template = param_name
-			output_def.scope = definition.code_template
-
-			# Note that these are not added to the _by_class_name dict
-			# because they only make sense within the entry block scope.
-			_catalog[output_def.name] = output_def
-
-
-static func _setup_output_definitions():
-	var definitions: Array[BlockDefinition]
-	definitions.assign(_catalog.values())
-	_add_output_definitions(definitions)
-
-
 static func _add_property_definitions(_class_name: String, property_list: Array[Dictionary], property_settings: Dictionary):
 	for property in property_list:
 		if not property.name in property_settings:
@@ -256,7 +222,6 @@ static func setup():
 
 	_catalog = {}
 	_setup_definitions_from_files()
-	_setup_output_definitions()
 	_setup_properties_for_class()
 	_setup_input_block()
 
@@ -330,7 +295,6 @@ static func add_custom_blocks(
 		_catalog[block_definition.name] = block_definition
 		_by_class_name[_class_name][block_definition.name] = block_definition
 
-	_add_output_definitions(block_definitions)
 	_add_property_definitions(_class_name, property_list, property_settings)
 
 
diff --git a/addons/block_code/drag_manager/drag_manager.gd b/addons/block_code/drag_manager/drag_manager.gd
index 033f1e8d..74a3fa85 100644
--- a/addons/block_code/drag_manager/drag_manager.gd
+++ b/addons/block_code/drag_manager/drag_manager.gd
@@ -15,6 +15,8 @@ const Util = preload("res://addons/block_code/ui/util.gd")
 
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 
+@onready var _context := BlockEditorContext.get_default()
+
 var _picker: Picker
 var _block_canvas: BlockCanvas
 
@@ -64,9 +66,9 @@ func drag_block(block: Block, copied_from: Block = null):
 
 
 func copy_block(block: Block) -> Block:
-	var new_block = Util.instantiate_block(block.definition)
-	new_block.color = block.color
-	return new_block
+	if _context.block_script == null:
+		return null
+	return _context.block_script.instantiate_block(block.definition)
 
 
 func copy_picked_block_and_drag(block: Block):
diff --git a/addons/block_code/serialization/block_script_serialization.gd b/addons/block_code/serialization/block_script_serialization.gd
index 02d61d22..f45844b1 100644
--- a/addons/block_code/serialization/block_script_serialization.gd
+++ b/addons/block_code/serialization/block_script_serialization.gd
@@ -4,14 +4,23 @@ extends Resource
 
 const ASTList = preload("res://addons/block_code/code_generation/ast_list.gd")
 const BlockAST = preload("res://addons/block_code/code_generation/block_ast.gd")
-const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
 const BlockCategory = preload("res://addons/block_code/ui/picker/categories/block_category.gd")
 const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
 const BlockSerialization = preload("res://addons/block_code/serialization/block_serialization.gd")
 const BlockSerializationTree = preload("res://addons/block_code/serialization/block_serialization_tree.gd")
+const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
+const CategoryFactory = preload("res://addons/block_code/ui/picker/categories/category_factory.gd")
+const Types = preload("res://addons/block_code/types/types.gd")
 const ValueBlockSerialization = preload("res://addons/block_code/serialization/value_block_serialization.gd")
 const VariableDefinition = preload("res://addons/block_code/code_generation/variable_definition.gd")
 
+const SCENE_PER_TYPE = {
+	Types.BlockType.ENTRY: preload("res://addons/block_code/ui/blocks/entry_block/entry_block.tscn"),
+	Types.BlockType.STATEMENT: preload("res://addons/block_code/ui/blocks/statement_block/statement_block.tscn"),
+	Types.BlockType.VALUE: preload("res://addons/block_code/ui/blocks/parameter_block/parameter_block.tscn"),
+	Types.BlockType.CONTROL: preload("res://addons/block_code/ui/blocks/control_block/control_block.tscn"),
+}
+
 @export var script_inherits: String
 @export var block_serialization_trees: Array[BlockSerializationTree]
 @export var variables: Array[VariableDefinition]:
@@ -19,7 +28,8 @@ const VariableDefinition = preload("res://addons/block_code/code_generation/vari
 @export var generated_script: String
 @export var version: int
 
-var _var_block_definitions: Dictionary  # String, BlockDefinition
+var _available_blocks: Array[BlockDefinition]
+var _categories: Array[BlockCategory]
 
 
 func _init(
@@ -32,36 +42,108 @@ func _init(
 	version = p_version
 
 
+func initialize():
+	_update_block_definitions()
+
+
 func _set_variables(value):
 	variables = value
-	_refresh_var_block_definitions()
+	_update_block_definitions()
 
 
-func _refresh_var_block_definitions():
-	_var_block_definitions.clear()
-	for block_def in BlocksCatalog.get_variable_block_definitions(variables):
-		_var_block_definitions[block_def.name] = block_def
+func instantiate_block(block_definition: BlockDefinition) -> Block:
+	if block_definition == null:
+		push_error("Cannot construct block from null block definition.")
+		return null
 
+	var scene := SCENE_PER_TYPE.get(block_definition.type)
+	if scene == null:
+		push_error("Cannot instantiate Block from type %s" % block_definition.type)
+		return null
 
-func _get_block(block_name: StringName) -> BlockDefinition:
-	var block_def: BlockDefinition = _var_block_definitions.get(block_name)
-	if block_def == null:
-		block_def = BlocksCatalog.get_block(block_name)
-	return block_def
+	var block_category := _get_category_by_name(block_definition.category)
 
+	var block: Block = scene.instantiate()
+	block.definition = block_definition
+	block.color = block_category.color if block_category else Color.WHITE
+	return block
 
-func get_definitions() -> Array[BlockDefinition]:
-	for class_dict in ProjectSettings.get_global_class_list():
-		if class_dict.class == script_inherits:
-			var script = load(class_dict.path)
-			if script.has_method("setup_custom_blocks"):
-				script.setup_custom_blocks()
-			break
 
-	return BlocksCatalog.get_inherited_blocks(script_inherits)
+func instantiate_block_by_name(block_name: String) -> Block:
+	var block_definition := get_block_definition(block_name)
+
+	if block_definition == null:
+		push_warning("Cannot find a block definition for %s" % block_name)
+		return null
+
+	return instantiate_block(block_definition)
+
+
+func get_block_definition(block_name: String) -> BlockDefinition:
+	var split := block_name.split(":", true, 1)
+
+	if len(split) > 1:
+		return _get_parameter_block_definition(split[0], split[1])
+
+	var block_definition = _get_base_block_definition(block_name)
+
+	if block_definition == null:
+		# FIXME: This is a workaround for old-style output block references.
+		#        These were generated ahead of time using a block name that has
+		#        a "_" before the parameter name. Now, these parameter blocks
+		#        are generated on demand for any block name containing a ":".
+		#        Please remove this fallback when it is no longer necessary.
+		split = block_name.rsplit("_", true, 1)
+		return _get_parameter_block_definition(split[0], split[1])
+
+	return block_definition
+
+
+func _get_base_block_definition(block_name: String) -> BlockDefinition:
+	for block_definition in _available_blocks:
+		if block_definition.name == block_name:
+			return block_definition
+	return null
+
+
+func _get_parameter_block_definition(block_name: String, parameter_name: String) -> BlockDefinition:
+	var base_block_definition := _get_base_block_definition(block_name)
+
+	if base_block_definition == null:
+		return null
+
+	var parent_out_parameters = base_block_definition.get_output_parameters()
+
+	if not parent_out_parameters.has(parameter_name):
+		push_error("The parameter name %s is not an output parameter in %s." % [parameter_name, block_name])
+		return null
+
+	var parameter_type: Variant.Type = parent_out_parameters[parameter_name]
+
+	var block_definition := BlockDefinition.new()
+	block_definition.name = &"%s:%s" % [block_name, parameter_name]
+	block_definition.target_node_class = base_block_definition.target_node_class
+	block_definition.category = base_block_definition.category
+	block_definition.type = Types.BlockType.VALUE
+	block_definition.variant_type = parameter_type
+	block_definition.display_template = parameter_name
+	block_definition.code_template = parameter_name
+	block_definition.scope = base_block_definition.code_template
+
+	return block_definition
+
+
+func _update_block_definitions():
+	_available_blocks.clear()
+	_available_blocks.append_array(_get_default_block_definitions())
+	_available_blocks.append_array(_get_inherited_block_definitions())
+	_available_blocks.append_array(_get_variable_block_definitions())
+
+	var custom_categories: Array[BlockCategory] = _get_custom_categories()
+	_categories = CategoryFactory.get_all_categories(custom_categories)
 
 
-func get_categories() -> Array[BlockCategory]:
+func _get_custom_categories() -> Array[BlockCategory]:
 	for class_dict in ProjectSettings.get_global_class_list():
 		if class_dict.class == script_inherits:
 			var script = load(class_dict.path)
@@ -71,6 +153,95 @@ func get_categories() -> Array[BlockCategory]:
 	return []
 
 
+func get_available_blocks() -> Array[BlockDefinition]:
+	return _available_blocks
+
+
+func get_available_categories() -> Array[BlockCategory]:
+	return _categories.filter(func(category): return _available_blocks.any(BlockDefinition.has_category.bind(category.name)))
+
+
+func get_blocks_in_category(category: BlockCategory) -> Array[BlockDefinition]:
+	return _available_blocks.filter(BlockDefinition.has_category.bind(category.name))
+
+
+func _get_category_by_name(category_name: String) -> BlockCategory:
+	return _categories.filter(func(category): return category.name == category_name).front()
+
+
+func load_object_script() -> Object:
+	for class_dict in ProjectSettings.get_global_class_list():
+		if class_dict.class == script_inherits:
+			return load(class_dict.path) as Object
+	return null
+
+
+func _get_default_block_definitions() -> Array[BlockDefinition]:
+	var block: BlockDefinition
+	var block_list: Array[BlockDefinition] = []
+
+	# Lifecycle
+	for block_name in [&"ready", &"process", &"physics_process", &"queue_free"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Loops
+	for block_name in [&"for", &"while", &"break", &"continue", &"await_scene_ready"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Logs
+	block = BlocksCatalog.get_block(&"print")
+	block_list.append(block)
+
+	# Communication
+	for block_name in [&"define_method", &"call_method_group", &"call_method_node"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	for block_name in [&"add_to_group", &"add_node_to_group", &"remove_from_group", &"remove_node_from_group", &"is_in_group", &"is_node_in_group"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Variables
+	block = BlocksCatalog.get_block(&"vector2")
+	block_list.append(block)
+
+	# Math
+	for block_name in [&"add", &"subtract", &"multiply", &"divide", &"pow", &"randf_range", &"randi_range", &"sin", &"cos", &"tan"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Logic
+	for block_name in [&"if", &"else_if", &"else", &"compare", &"and", &"or", &"not"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Input
+	block = BlocksCatalog.get_block(&"is_input_actioned")
+	block_list.append(block)
+
+	# Sounds
+	for block_name in [&"load_sound", &"play_sound", &"pause_continue_sound", &"stop_sound"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	# Graphics
+	for block_name in [&"viewport_width", &"viewport_height", &"viewport_center"]:
+		block = BlocksCatalog.get_block(block_name)
+		block_list.append(block)
+
+	return block_list
+
+
+func _get_inherited_block_definitions() -> Array[BlockDefinition]:
+	return BlocksCatalog.get_inherited_blocks(script_inherits)
+
+
+func _get_variable_block_definitions() -> Array[BlockDefinition]:
+	return BlocksCatalog.get_variable_block_definitions(variables)
+
+
 func generate_ast_list() -> ASTList:
 	var ast_list := ASTList.new()
 	for tree in block_serialization_trees:
@@ -87,7 +258,7 @@ func _tree_to_ast(tree: BlockSerializationTree) -> BlockAST:
 
 func _block_to_ast_node(node: BlockSerialization) -> BlockAST.ASTNode:
 	var ast_node := BlockAST.ASTNode.new()
-	ast_node.data = _get_block(node.name)
+	ast_node.data = get_block_definition(node.name)
 
 	for arg_name in node.arguments:
 		var argument = node.arguments[arg_name]
@@ -105,7 +276,7 @@ func _block_to_ast_node(node: BlockSerialization) -> BlockAST.ASTNode:
 
 func _value_to_ast_value(value_node: ValueBlockSerialization) -> BlockAST.ASTValueNode:
 	var ast_value_node := BlockAST.ASTValueNode.new()
-	ast_value_node.data = _get_block(value_node.name)
+	ast_value_node.data = get_block_definition(value_node.name)
 
 	for arg_name in value_node.arguments:
 		var argument = value_node.arguments[arg_name]
diff --git a/addons/block_code/ui/block_canvas/block_canvas.gd b/addons/block_code/ui/block_canvas/block_canvas.gd
index c3095170..34b1c3e8 100644
--- a/addons/block_code/ui/block_canvas/block_canvas.gd
+++ b/addons/block_code/ui/block_canvas/block_canvas.gd
@@ -15,6 +15,8 @@ const DEFAULT_WINDOW_MARGIN: Vector2 = Vector2(25, 25)
 const SNAP_GRID: Vector2 = Vector2(25, 25)
 const ZOOM_FACTOR: float = 1.1
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _window: Control = %Window
 @onready var _empty_box: BoxContainer = %EmptyBox
 
@@ -52,6 +54,8 @@ signal replace_block_code
 
 
 func _ready():
+	_context.changed.connect(_on_context_changed)
+
 	if not _open_scene_button.icon and not Util.node_is_part_of_edited_scene(self):
 		_open_scene_button.icon = _open_scene_icon
 
@@ -87,12 +91,12 @@ func set_child(n: Node):
 		set_child(c)
 
 
-func block_script_selected(block_script: BlockScriptSerialization):
+func _on_context_changed():
 	clear_canvas()
 
 	var edited_node = EditorInterface.get_inspector().get_edited_object() as Node
 
-	if block_script != _current_block_script:
+	if _context.block_script != _current_block_script:
 		_window.position = Vector2(0, 0)
 		zoom = 1
 
@@ -106,12 +110,12 @@ func block_script_selected(block_script: BlockScriptSerialization):
 	_open_scene_button.disabled = true
 	_replace_block_code_button.disabled = true
 
-	if block_script != null:
-		_load_block_script(block_script)
+	if _context.block_script != null:
+		_load_block_script(_context.block_script)
 		_window.visible = true
 		_zoom_button.visible = true
 
-		if block_script != _current_block_script:
+		if _context.block_script != _current_block_script:
 			reset_window_position()
 	elif edited_node == null:
 		_empty_box.visible = true
@@ -130,7 +134,7 @@ func block_script_selected(block_script: BlockScriptSerialization):
 		_selected_node_label.text = _selected_node_label_format.format({"node": edited_node.name})
 		_add_block_code_button.disabled = false
 
-	_current_block_script = block_script
+	_current_block_script = _context.block_script
 
 
 func _load_block_script(block_script: BlockScriptSerialization):
@@ -146,8 +150,8 @@ func reload_ui_from_ast_list():
 
 
 func ui_tree_from_ast_node(ast_node: BlockAST.ASTNode) -> Block:
-	var block: Block = Util.instantiate_block(ast_node.data)
-	block.color = Util.get_category_color(ast_node.data.category)
+	var block: Block = _context.block_script.instantiate_block(ast_node.data)
+
 	# Args
 	for arg_name in ast_node.arguments:
 		var argument = ast_node.arguments[arg_name]
@@ -177,8 +181,8 @@ func ui_tree_from_ast_node(ast_node: BlockAST.ASTNode) -> Block:
 
 
 func ui_tree_from_ast_value_node(ast_value_node: BlockAST.ASTValueNode) -> Block:
-	var block: Block = Util.instantiate_block(ast_value_node.data)
-	block.color = Util.get_category_color(ast_value_node.data.category)
+	var block: Block = _context.block_script.instantiate_block(ast_value_node.data)
+
 	# Args
 	for arg_name in ast_value_node.arguments:
 		var argument = ast_value_node.arguments[arg_name]
@@ -259,7 +263,7 @@ func build_value_ast(block: ParameterBlock) -> BlockAST.ASTValueNode:
 
 
 func rebuild_block_serialization_trees():
-	_current_block_script.update_from_ast_list(_current_ast_list)
+	_context.block_script.update_from_ast_list(_current_ast_list)
 
 
 func find_snaps(node: Node) -> Array[SnapPoint]:
@@ -383,7 +387,7 @@ func set_mouse_override(override: bool):
 
 
 func generate_script_from_current_window() -> String:
-	return ScriptGenerator.generate_script(_current_ast_list, _current_block_script)
+	return ScriptGenerator.generate_script(_current_ast_list, _context.block_script)
 
 
 func _on_zoom_button_pressed():
diff --git a/addons/block_code/ui/block_editor_context.gd b/addons/block_code/ui/block_editor_context.gd
new file mode 100644
index 00000000..6c36bba1
--- /dev/null
+++ b/addons/block_code/ui/block_editor_context.gd
@@ -0,0 +1,33 @@
+class_name BlockEditorContext
+extends Object
+
+signal changed
+
+static var _instance: BlockEditorContext
+
+var block_code_node: BlockCode:
+	set(value):
+		block_code_node = value
+		changed.emit()
+
+var block_script: BlockScriptSerialization:
+	get:
+		if block_code_node == null:
+			return null
+		return block_code_node.block_script
+
+var parent_node: Node:
+	get:
+		if block_code_node == null:
+			return null
+		return block_code_node.get_parent()
+
+
+func force_update() -> void:
+	changed.emit()
+
+
+static func get_default() -> BlockEditorContext:
+	if _instance == null:
+		_instance = BlockEditorContext.new()
+	return _instance
diff --git a/addons/block_code/ui/blocks/block/block.gd b/addons/block_code/ui/blocks/block/block.gd
index 741d31c4..499927ca 100644
--- a/addons/block_code/ui/blocks/block/block.gd
+++ b/addons/block_code/ui/blocks/block/block.gd
@@ -10,9 +10,6 @@ signal modified
 ## Color of block (optionally used to draw block color)
 @export var color: Color = Color(1., 1., 1.)
 
-## Category to add the block to
-@export var category: String
-
 # FIXME Note: This used to be a NodePath. There is a bug in Godot 4.2 that causes the
 # reference to not be set properly when the node is duplicated. Since we don't
 # use the Node duplicate function anymore, this is okay.
diff --git a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
index 0fb715cc..579d3102 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
+++ b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
@@ -5,10 +5,15 @@ extends MarginContainer
 const Types = preload("res://addons/block_code/types/types.gd")
 
 var block: Block
-var output_block: Block
+var parameter_name: String
+var _block_name: String:
+	get:
+		return block.definition.name if block else ""
 
 @export var block_params: Dictionary
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _snap_point := %SnapPoint
 
 
@@ -22,10 +27,17 @@ func _update_parameter_block():
 	if _snap_point.has_snapped_block():
 		return
 
-	var parameter_block = preload("res://addons/block_code/ui/blocks/parameter_block/parameter_block.tscn").instantiate()
-	for key in block_params:
-		parameter_block[key] = block_params[key]
-	parameter_block.spawned_by = self
+	if _context.block_script == null:
+		return
+
+	var block_name = &"%s:%s" % [_block_name, parameter_name]
+	var parameter_block: ParameterBlock = _context.block_script.instantiate_block_by_name(block_name)
+
+	if parameter_block == null:
+		# FIXME: This sometimes occurs when a script is loaded but it is unclear why
+		#push_error("Unable to create output block %s." % block_name)
+		return
+
 	_snap_point.add_child.call_deferred(parameter_block)
 
 
diff --git a/addons/block_code/ui/main_panel.gd b/addons/block_code/ui/main_panel.gd
index 64ea1f90..cb4dabd5 100644
--- a/addons/block_code/ui/main_panel.gd
+++ b/addons/block_code/ui/main_panel.gd
@@ -5,11 +5,14 @@ signal script_window_requested(script: String)
 
 const BlockCanvas = preload("res://addons/block_code/ui/block_canvas/block_canvas.gd")
 const BlockCodePlugin = preload("res://addons/block_code/block_code_plugin.gd")
+const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
 const DragManager = preload("res://addons/block_code/drag_manager/drag_manager.gd")
 const Picker = preload("res://addons/block_code/ui/picker/picker.gd")
 const TitleBar = preload("res://addons/block_code/ui/title_bar/title_bar.gd")
 const VariableDefinition = preload("res://addons/block_code/code_generation/variable_definition.gd")
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _picker: Picker = %Picker
 @onready var _block_canvas: BlockCanvas = %BlockCanvas
 @onready var _drag_manager: DragManager = %DragManager
@@ -25,7 +28,6 @@ const VariableDefinition = preload("res://addons/block_code/code_generation/vari
 
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 
-var _current_block_code_node: BlockCode
 var _block_code_nodes: Array
 var _collapsed: bool = false
 
@@ -39,6 +41,8 @@ var undo_redo: EditorUndoRedoManager:
 
 
 func _ready():
+	_context.changed.connect(_on_context_changed)
+
 	_picker.block_picked.connect(_drag_manager.copy_picked_block_and_drag)
 	_picker.variable_created.connect(_create_variable)
 	_block_canvas.reconnect_block.connect(_drag_manager.connect_block_canvas_signals)
@@ -52,13 +56,7 @@ func _ready():
 
 
 func _on_undo_redo_version_changed():
-	if _current_block_code_node == null:
-		return
-
-	var block_script: BlockScriptSerialization = _current_block_code_node.block_script
-	_picker.block_script_selected(block_script)
-	_title_bar.block_script_selected(block_script)
-	_block_canvas.block_script_selected(block_script)
+	_context.force_update()
 
 
 func _on_show_script_button_pressed():
@@ -73,15 +71,14 @@ func _on_delete_node_button_pressed():
 	if not scene_root:
 		return
 
-	if not _current_block_code_node:
+	if not _context.block_code_node:
 		return
 
 	var dialog = ConfirmationDialog.new()
 	var text_format: String = 'Delete block code ("{node}") for "{parent}"?'
-	dialog.dialog_text = text_format.format({"node": _current_block_code_node.name, "parent": _current_block_code_node.get_parent().name})
+	dialog.dialog_text = text_format.format({"node": _context.block_code_node.name, "parent": _context.parent_node.name})
 	EditorInterface.popup_dialog_centered(dialog)
-	dialog.connect("confirmed", _on_delete_dialog_confirmed.bind(_current_block_code_node))
-	pass  # Replace with function body.
+	dialog.connect("confirmed", _on_delete_dialog_confirmed.bind(_context.block_code_node))
 
 
 func _on_delete_dialog_confirmed(block_code_node: BlockCode):
@@ -90,7 +87,7 @@ func _on_delete_dialog_confirmed(block_code_node: BlockCode):
 	if not parent_node:
 		return
 
-	undo_redo.create_action("Delete %s's block code script" % _current_block_code_node.get_parent().name, UndoRedo.MERGE_DISABLE, parent_node)
+	undo_redo.create_action("Delete %s's block code script" % parent_node.name, UndoRedo.MERGE_DISABLE, parent_node)
 	undo_redo.add_do_property(block_code_node, "owner", null)
 	undo_redo.add_do_method(parent_node, "remove_child", block_code_node)
 	undo_redo.add_undo_method(parent_node, "add_child", block_code_node)
@@ -100,53 +97,59 @@ func _on_delete_dialog_confirmed(block_code_node: BlockCode):
 
 
 func _try_migration():
-	var version: int = _current_block_code_node.block_script.version
+	var version: int = _context.block_script.version
 	if version == Constants.CURRENT_DATA_VERSION:
 		# No migration needed.
 		return
 	push_warning("Migration not implemented from %d to %d" % [version, Constants.CURRENT_DATA_VERSION])
 
 
-func switch_scene(scene_root: Node):
-	_title_bar.scene_selected(scene_root)
+func switch_block_code_node(block_code_node: BlockCode):
+	BlocksCatalog.setup()
+
+	var block_script := block_code_node.block_script if block_code_node != null else null
+	var object_script := block_script.load_object_script() if block_script != null else null
 
+	if object_script and object_script.has_method("setup_custom_blocks"):
+		object_script.setup_custom_blocks()
 
-func switch_block_code_node(block_code_node: BlockCode):
-	var block_script: BlockScriptSerialization = block_code_node.block_script if block_code_node else null
-	_current_block_code_node = block_code_node
-	_delete_node_button.disabled = _current_block_code_node == null
-	if _current_block_code_node != null:
+	if block_script:
+		block_script.initialize()
+
+	_context.block_code_node = block_code_node
+
+
+func _on_context_changed():
+	_delete_node_button.disabled = _context.block_code_node == null
+	if _context.block_code_node != null:
 		_try_migration()
-	_picker.block_script_selected(block_script)
-	_title_bar.block_script_selected(block_script)
-	_block_canvas.block_script_selected(block_script)
 
 
 func save_script():
-	if _current_block_code_node == null:
+	if _context.block_code_node == null:
 		print("No script loaded to save.")
 		return
 
 	var scene_node = EditorInterface.get_edited_scene_root()
 
-	if not BlockCodePlugin.is_block_code_editable(_current_block_code_node):
-		print("Block code for {node} is not editable.".format({"node": _current_block_code_node}))
+	if not BlockCodePlugin.is_block_code_editable(_context.block_code_node):
+		print("Block code for {node} is not editable.".format({"node": _context.block_code_node}))
 		return
 
-	var block_script: BlockScriptSerialization = _current_block_code_node.block_script
+	var block_script: BlockScriptSerialization = _context.block_script
 
 	var resource_path_split = block_script.resource_path.split("::", true, 1)
 	var resource_scene = resource_path_split[0]
 
-	undo_redo.create_action("Modify %s's block code script" % _current_block_code_node.get_parent().name, UndoRedo.MERGE_DISABLE, _current_block_code_node)
+	undo_redo.create_action("Modify %s's block code script" % _context.parent_node.name, UndoRedo.MERGE_DISABLE, _context.block_code_node)
 
 	if resource_scene and resource_scene != scene_node.scene_file_path:
 		# This resource is from another scene. Since the user is changing it
 		# here, we'll make a copy for this scene rather than changing it in the
 		# other scene file.
-		undo_redo.add_undo_property(_current_block_code_node, "block_script", _current_block_code_node.block_script)
+		undo_redo.add_undo_property(_context.block_code_node, "block_script", _context.block_script)
 		block_script = block_script.duplicate(true)
-		undo_redo.add_do_property(_current_block_code_node, "block_script", block_script)
+		undo_redo.add_do_property(_context.block_code_node, "block_script", block_script)
 
 	undo_redo.add_undo_property(block_script, "block_serialization_trees", block_script.block_serialization_trees)
 	_block_canvas.rebuild_ast_list()
@@ -264,19 +267,19 @@ func _set_selection(nodes: Array[Node]):
 
 
 func _create_variable(variable: VariableDefinition):
-	if _current_block_code_node == null:
+	if _context.block_code_node == null:
 		print("No script loaded to add variable to.")
 		return
 
-	var block_script: BlockScriptSerialization = _current_block_code_node.block_script
+	var block_script: BlockScriptSerialization = _context.block_script
 
-	undo_redo.create_action("Create variable %s in %s's block code script" % [variable.var_name, _current_block_code_node.get_parent().name])
-	undo_redo.add_undo_property(_current_block_code_node.block_script, "variables", _current_block_code_node.block_script.variables)
+	undo_redo.create_action("Create variable %s in %s's block code script" % [variable.var_name, _context.parent_node.name])
+	undo_redo.add_undo_property(_context.block_script, "variables", _context.block_script.variables)
 
 	var new_variables = block_script.variables.duplicate()
 	new_variables.append(variable)
 
-	undo_redo.add_do_property(_current_block_code_node.block_script, "variables", new_variables)
+	undo_redo.add_do_property(_context.block_script, "variables", new_variables)
 	undo_redo.commit_action()
 
-	_picker.reload_variables(new_variables)
+	_picker.reload_blocks()
diff --git a/addons/block_code/ui/picker/categories/block_category.gd b/addons/block_code/ui/picker/categories/block_category.gd
index e076865d..1169c35a 100644
--- a/addons/block_code/ui/picker/categories/block_category.gd
+++ b/addons/block_code/ui/picker/categories/block_category.gd
@@ -1,15 +1,18 @@
 extends RefCounted
 
-const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
-
 var name: String
-var block_list: Array[BlockDefinition]
 var color: Color
 var order: int
 
 
-func _init(p_name: String = "", p_color: Color = Color.WHITE, p_order: int = 0, p_block_list: Array[BlockDefinition] = []):
+func _init(p_name: String = "", p_color: Color = Color.WHITE, p_order: int = 0):
 	name = p_name
-	block_list = p_block_list
 	color = p_color
 	order = p_order
+
+
+## Compare block categories for sorting. Compare by order then name.
+static func sort_by_order(a, b) -> bool:
+	if a.order != b.order:
+		return a.order < b.order
+	return a.name.naturalcasecmp_to(b.name) < 0
diff --git a/addons/block_code/ui/picker/categories/block_category_display.gd b/addons/block_code/ui/picker/categories/block_category_display.gd
index 5145836a..73fd1e63 100644
--- a/addons/block_code/ui/picker/categories/block_category_display.gd
+++ b/addons/block_code/ui/picker/categories/block_category_display.gd
@@ -8,15 +8,20 @@ const Util = preload("res://addons/block_code/ui/util.gd")
 
 var category: BlockCategory
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _label := %Label
 @onready var _blocks := %Blocks
 
 
 func _ready():
-	_label.text = category.name
+	_label.text = category.name if category != null else ""
+
+	if _context.block_script == null:
+		return
 
-	for block_definition in category.block_list:
-		var block: Block = Util.instantiate_block(block_definition)
+	for block_definition in _context.block_script.get_blocks_in_category(category):
+		var block: Block = _context.block_script.instantiate_block(block_definition)
 
 		block.color = category.color
 		block.can_delete = false
diff --git a/addons/block_code/ui/picker/categories/category_factory.gd b/addons/block_code/ui/picker/categories/category_factory.gd
index 02eda12b..2a508d33 100644
--- a/addons/block_code/ui/picker/categories/category_factory.gd
+++ b/addons/block_code/ui/picker/categories/category_factory.gd
@@ -2,105 +2,20 @@ class_name CategoryFactory
 extends Object
 
 const BlockCategory = preload("res://addons/block_code/ui/picker/categories/block_category.gd")
-const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
-const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
-const Types = preload("res://addons/block_code/types/types.gd")
-const Util = preload("res://addons/block_code/ui/util.gd")
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 
 
-## Compare block categories for sorting. Compare by order then name.
-static func _category_cmp(a: BlockCategory, b: BlockCategory) -> bool:
-	if a.order != b.order:
-		return a.order < b.order
-	return a.name.naturalcasecmp_to(b.name) < 0
+## Returns a list of BlockCategory instances for all block categories.
+static func get_all_categories(custom_categories: Array[BlockCategory] = []) -> Array[BlockCategory]:
+	var result: Array[BlockCategory]
 
+	for category_name in Constants.BUILTIN_CATEGORIES_PROPS:
+		var props: Dictionary = Constants.BUILTIN_CATEGORIES_PROPS.get(category_name, {})
+		var color: Color = props.get("color", Color.SLATE_GRAY)
+		var order: int = props.get("order", 0)
+		result.append(BlockCategory.new(category_name, color, order))
 
-static func get_categories(blocks: Array[BlockDefinition], extra_categories: Array[BlockCategory] = []) -> Array[BlockCategory]:
-	var cat_map: Dictionary = {}
-	var extra_cat_map: Dictionary = {}
+	# TODO: Should we deduplicate custom_categories here?
+	result.append_array(custom_categories)
 
-	for cat in extra_categories:
-		extra_cat_map[cat.name] = cat
-
-	for block in blocks:
-		var cat: BlockCategory = cat_map.get(block.category)
-		if cat == null:
-			cat = extra_cat_map.get(block.category)
-			if cat == null:
-				var props: Dictionary = Constants.BUILTIN_CATEGORIES_PROPS.get(block.category, {})
-				var color: Color = props.get("color", Color.SLATE_GRAY)
-				var order: int = props.get("order", 0)
-				cat = BlockCategory.new(block.category, color, order)
-			cat_map[block.category] = cat
-		cat.block_list.append(block)
-
-	# Dictionary.values() returns an untyped Array and there's no way to
-	# convert an array type besides Array.assign().
-	var cats: Array[BlockCategory] = []
-	cats.assign(cat_map.values())
-	# Accessing a static Callable from a static function fails in 4.2.1.
-	# Use the fully qualified name.
-	# https://github.com/godotengine/godot/issues/86032
-	cats.sort_custom(CategoryFactory._category_cmp)
-	return cats
-
-
-static func get_general_blocks() -> Array[BlockDefinition]:
-	var block: BlockDefinition
-	var block_list: Array[BlockDefinition] = []
-
-	BlocksCatalog.setup()
-
-	# Lifecycle
-	for block_name in [&"ready", &"process", &"physics_process", &"queue_free"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Loops
-	for block_name in [&"for", &"while", &"break", &"continue", &"await_scene_ready"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Logs
-	block = BlocksCatalog.get_block(&"print")
-	block_list.append(block)
-
-	# Communication
-	for block_name in [&"define_method", &"call_method_group", &"call_method_node"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	for block_name in [&"add_to_group", &"add_node_to_group", &"remove_from_group", &"remove_node_from_group", &"is_in_group", &"is_node_in_group"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Variables
-	block = BlocksCatalog.get_block(&"vector2")
-	block_list.append(block)
-
-	# Math
-	for block_name in [&"add", &"subtract", &"multiply", &"divide", &"pow", &"randf_range", &"randi_range", &"sin", &"cos", &"tan"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Logic
-	for block_name in [&"if", &"else_if", &"else", &"compare", &"and", &"or", &"not"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Input
-	block = BlocksCatalog.get_block(&"is_input_actioned")
-	block_list.append(block)
-
-	# Sounds
-	for block_name in [&"load_sound", &"play_sound", &"pause_continue_sound", &"stop_sound"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Graphics
-	for block_name in [&"viewport_width", &"viewport_height", &"viewport_center"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	return block_list
+	return result
diff --git a/addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd b/addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd
index cc818d43..8383bbb5 100644
--- a/addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd
+++ b/addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd
@@ -5,6 +5,8 @@ const BlockCodePlugin = preload("res://addons/block_code/block_code_plugin.gd")
 
 signal create_variable(var_name: String, var_type: String)
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _variable_input := %VariableInput
 @onready var _type_option := %TypeOption
 @onready var _messages := %Messages
@@ -60,14 +62,11 @@ func check_errors(new_var_name: String) -> bool:
 		errors.append("Variable name cannot contain special characters")
 
 	var duplicate_variable_name := false
-	var current_block_code = BlockCodePlugin.main_panel._current_block_code_node
-	if current_block_code:
-		var current_block_script = current_block_code.block_script
-		if current_block_script:
-			for variable in current_block_script.variables:
-				if variable.var_name == new_var_name:
-					duplicate_variable_name = true
-					break
+	if _context.block_script:
+		for variable in _context.block_script.variables:
+			if variable.var_name == new_var_name:
+				duplicate_variable_name = true
+				break
 
 	if duplicate_variable_name:
 		errors.append("Variable already exists")
diff --git a/addons/block_code/ui/picker/picker.gd b/addons/block_code/ui/picker/picker.gd
index d2fbd4c2..49b90d81 100644
--- a/addons/block_code/ui/picker/picker.gd
+++ b/addons/block_code/ui/picker/picker.gd
@@ -6,7 +6,6 @@ const BlockCategory = preload("res://addons/block_code/ui/picker/categories/bloc
 const BlockCategoryButtonScene = preload("res://addons/block_code/ui/picker/categories/block_category_button.tscn")
 const BlockCategoryButton = preload("res://addons/block_code/ui/picker/categories/block_category_button.gd")
 const BlockCategoryDisplay = preload("res://addons/block_code/ui/picker/categories/block_category_display.gd")
-const CategoryFactory = preload("res://addons/block_code/ui/picker/categories/category_factory.gd")
 const Util = preload("res://addons/block_code/ui/util.gd")
 const VariableCategoryDisplay = preload("res://addons/block_code/ui/picker/categories/variable_category/variable_category_display.gd")
 const VariableDefinition = preload("res://addons/block_code/code_generation/variable_definition.gd")
@@ -14,6 +13,8 @@ const VariableDefinition = preload("res://addons/block_code/code_generation/vari
 signal block_picked(block: Block)
 signal variable_created(variable: VariableDefinition)
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _block_list := %BlockList
 @onready var _block_scroll := %BlockScroll
 @onready var _category_list := %CategoryList
@@ -23,35 +24,31 @@ var scroll_tween: Tween
 var _variable_category_display: VariableCategoryDisplay = null
 
 
-func block_script_selected(block_script: BlockScriptSerialization):
-	if not block_script:
-		reset_picker()
-		return
+func _ready() -> void:
+	_context.changed.connect(_on_context_changed)
 
-	var blocks_to_add: Array[BlockDefinition] = block_script.get_definitions()
-	var categories_to_add: Array[BlockCategory] = block_script.get_categories()
 
-	init_picker(blocks_to_add, categories_to_add)
-	reload_variables(block_script.variables)
+func _on_context_changed():
+	_block_scroll.scroll_vertical = 0
+	_update_block_components()
 
 
-func reset_picker():
-	for c in _category_list.get_children():
-		c.queue_free()
+func reload_blocks():
+	_update_block_components()
 
-	for c in _block_list.get_children():
-		c.queue_free()
 
+func _update_block_components():
+	# FIXME: Instead, we should reuse existing CategoryList and BlockList components.
+	_reset_picker()
 
-func init_picker(extra_blocks: Array[BlockDefinition] = [], extra_categories: Array[BlockCategory] = []):
-	reset_picker()
+	if not _context.block_script:
+		return
 
-	var blocks := CategoryFactory.get_general_blocks() + extra_blocks
-	var block_categories := CategoryFactory.get_categories(blocks, extra_categories)
+	var block_categories := _context.block_script.get_available_categories()
 
-	for _category in block_categories:
-		var category: BlockCategory = _category as BlockCategory
+	block_categories.sort_custom(BlockCategory.sort_by_order)
 
+	for category in block_categories:
 		var block_category_button: BlockCategoryButton = BlockCategoryButtonScene.instantiate()
 		block_category_button.category = category
 		block_category_button.selected.connect(_category_selected)
@@ -71,7 +68,15 @@ func init_picker(extra_blocks: Array[BlockDefinition] = [], extra_categories: Ar
 
 		_block_list.add_child(block_category_display)
 
-		_block_scroll.scroll_vertical = 0
+
+func _reset_picker():
+	for node in _category_list.get_children():
+		_category_list.remove_child(node)
+		node.queue_free()
+
+	for node in _block_list.get_children():
+		_block_list.remove_child(node)
+		node.queue_free()
 
 
 func scroll_to(y: float):
@@ -90,19 +95,3 @@ func _category_selected(category: BlockCategory):
 
 func set_collapsed(collapsed: bool):
 	_widget_container.visible = not collapsed
-
-
-func reload_variables(variables: Array[VariableDefinition]):
-	if _variable_category_display:
-		for c in _variable_category_display.variable_blocks.get_children():
-			c.queue_free()
-
-		var i := 1
-		for block in Util.instantiate_variable_blocks(variables):
-			_variable_category_display.variable_blocks.add_child(block)
-			block.drag_started.connect(func(block: Block): block_picked.emit(block))
-			if i % 2 == 0:
-				var spacer := Control.new()
-				spacer.custom_minimum_size.y = 12
-				_variable_category_display.variable_blocks.add_child(spacer)
-			i += 1
diff --git a/addons/block_code/ui/title_bar/title_bar.gd b/addons/block_code/ui/title_bar/title_bar.gd
index 710c4344..f2dfc45c 100644
--- a/addons/block_code/ui/title_bar/title_bar.gd
+++ b/addons/block_code/ui/title_bar/title_bar.gd
@@ -5,6 +5,8 @@ const BlockCodePlugin = preload("res://addons/block_code/block_code_plugin.gd")
 
 signal node_name_changed(node_name: String)
 
+@onready var _context := BlockEditorContext.get_default()
+
 @onready var _block_code_icon = load("res://addons/block_code/block_code_node/block_code_node.svg") as Texture2D
 @onready var _editor_inspector: EditorInspector = EditorInterface.get_inspector()
 @onready var _editor_selection: EditorSelection = EditorInterface.get_selection()
@@ -12,17 +14,11 @@ signal node_name_changed(node_name: String)
 
 
 func _ready():
+	_context.changed.connect(_on_context_changed)
 	_node_option_button.connect("item_selected", _on_node_option_button_item_selected)
 
 
-func scene_selected(scene_root: Node):
-	_update_node_option_button_items()
-	var current_block_code = _editor_inspector.get_edited_object() as BlockCode
-	if not current_block_code:
-		block_script_selected(null)
-
-
-func block_script_selected(block_script: BlockScriptSerialization):
+func _on_context_changed():
 	# TODO: We should listen for property changes in all BlockCode nodes and
 	#       their parents. As a workaround for the UI displaying stale data,
 	#       we'll crudely update the list of BlockCode nodes whenever the
@@ -30,7 +26,7 @@ func block_script_selected(block_script: BlockScriptSerialization):
 
 	_update_node_option_button_items()
 
-	var select_index = _get_block_script_index(block_script)
+	var select_index = _get_block_script_index(_context.block_script)
 	if _node_option_button.selected != select_index:
 		_node_option_button.select(select_index)
 
@@ -53,6 +49,8 @@ func _update_node_option_button_items():
 		_node_option_button.set_item_icon(node_item_index, _block_code_icon)
 		_node_option_button.set_item_metadata(node_item_index, block_code)
 
+	_node_option_button.disabled = _node_option_button.item_count == 0
+
 
 func _get_block_script_index(block_script: BlockScriptSerialization) -> int:
 	for index in range(_node_option_button.item_count):
diff --git a/addons/block_code/ui/util.gd b/addons/block_code/ui/util.gd
index 076d1f84..46918d2f 100644
--- a/addons/block_code/ui/util.gd
+++ b/addons/block_code/ui/util.gd
@@ -1,48 +1,5 @@
 extends Object
 
-const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
-const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
-const Types = preload("res://addons/block_code/types/types.gd")
-const Constants = preload("res://addons/block_code/ui/constants.gd")
-const VariableDefinition = preload("res://addons/block_code/code_generation/variable_definition.gd")
-
-const SCENE_PER_TYPE = {
-	Types.BlockType.ENTRY: preload("res://addons/block_code/ui/blocks/entry_block/entry_block.tscn"),
-	Types.BlockType.STATEMENT: preload("res://addons/block_code/ui/blocks/statement_block/statement_block.tscn"),
-	Types.BlockType.VALUE: preload("res://addons/block_code/ui/blocks/parameter_block/parameter_block.tscn"),
-	Types.BlockType.CONTROL: preload("res://addons/block_code/ui/blocks/control_block/control_block.tscn"),
-}
-
-
-static func get_category_color(category: String) -> Color:
-	var category_props: Dictionary = Constants.BUILTIN_CATEGORIES_PROPS.get(category, {})
-	return category_props.get("color", Color.SLATE_GRAY)
-
-
-static func instantiate_block(block_definition: BlockDefinition) -> Block:
-	if block_definition == null:
-		push_error("Cannot construct block from null block definition.")
-		return null
-
-	var scene = SCENE_PER_TYPE.get(block_definition.type)
-	if scene == null:
-		push_error("Cannot instantiate Block from type %s" % block_definition.type)
-		return null
-
-	var block = scene.instantiate()
-	block.definition = block_definition
-	return block
-
-
-static func instantiate_variable_blocks(variables: Array[VariableDefinition]) -> Array[Block]:
-	var blocks: Array[Block] = []
-	for block_definition in BlocksCatalog.get_variable_block_definitions(variables):
-		var block = instantiate_block(block_definition)
-		block.color = get_category_color(block_definition.category)
-		blocks.append(block)
-
-	return blocks
-
 
 ## Polyfill of Node.is_part_of_edited_scene(), available to GDScript in Godot 4.3+.
 static func node_is_part_of_edited_scene(node: Node) -> bool:
diff --git a/tests/test_category_factory.gd b/tests/test_category_factory.gd
index 99dbfd11..4273b7f6 100644
--- a/tests/test_category_factory.gd
+++ b/tests/test_category_factory.gd
@@ -1,27 +1,36 @@
 extends GutTest
-## Tests for CategoryFactory
+## Tests for BlockFactory
 
 const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
 const BlockCategory = preload("res://addons/block_code/ui/picker/categories/block_category.gd")
 const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
 
+var block_script: BlockScriptSerialization
+
 
 func get_category_names(categories: Array[BlockCategory]) -> Array[String]:
-	var names: Array[String] = []
-	for category in categories:
-		names.append(category.name)
-	return names
+	var categories_sorted: Array[BlockCategory]
+	categories_sorted.assign(categories)
+	categories_sorted.sort_custom(BlockCategory.sort_by_order)
+	var result: Array[String]
+	result.assign(categories_sorted.map(func(category): return category.name))
+	return result
 
 
 func get_class_category_names(_class_name: String) -> Array[String]:
 	var blocks: Array[BlockDefinition] = BlocksCatalog.get_inherited_blocks(_class_name)
-	var names: Array[String] = get_category_names(CategoryFactory.get_categories(blocks))
-	return names
+	var categories: Array[BlockCategory] = block_script._categories.filter(func(category): return blocks.any(func(block): return block.category == category.name))
+	return get_category_names(categories)
+
+
+func before_each():
+	block_script = BlockScriptSerialization.new()
+	block_script.initialize()
 
 
 func test_general_category_names():
-	var blocks: Array[BlockDefinition] = CategoryFactory.get_general_blocks()
-	var names: Array[String] = get_category_names(CategoryFactory.get_categories(blocks))
+	var blocks: Array[BlockDefinition] = block_script.get_available_blocks()
+	var names: Array[String] = get_category_names(block_script.get_available_categories())
 	assert_eq(
 		names,
 		[
@@ -55,7 +64,7 @@ func test_inherited_category_names(params = use_parameters(class_category_names)
 
 
 func test_unique_block_names():
-	var blocks: Array[BlockDefinition] = CategoryFactory.get_general_blocks()
+	var blocks: Array[BlockDefinition] = block_script.get_available_blocks()
 	var block_names: Dictionary
 	for block in blocks:
 		assert_does_not_have(block_names, block.name, "Block name %s is duplicated" % block.name)
diff --git a/tests/test_code_generation.gd b/tests/test_code_generation.gd
index 7e61602e..9e960480 100644
--- a/tests/test_code_generation.gd
+++ b/tests/test_code_generation.gd
@@ -9,6 +9,7 @@ const BlockDefinition = preload("res://addons/block_code/code_generation/block_d
 const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
 
 var general_blocks: Dictionary
+var block_script: BlockScriptSerialization
 
 
 func build_block_map(block_map: Dictionary, blocks: Array[BlockDefinition]):
@@ -24,7 +25,9 @@ func free_block_map(block_map: Dictionary):
 
 
 func before_each():
-	build_block_map(general_blocks, CategoryFactory.get_general_blocks())
+	block_script = BlockScriptSerialization.new()
+	block_script.initialize()
+	build_block_map(general_blocks, block_script.get_available_blocks())
 
 
 func after_each():

From 4118bae8efd175e7b8ae57fc167ff455db57222b Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Wed, 18 Sep 2024 14:49:57 -0700
Subject: [PATCH 02/13] BlocksCatalog: Remove by_class_name cache

Instead, the list of blocks by class name is generated as needed inside
get_blocks_by_class.
---
 .../code_generation/blocks_catalog.gd         | 32 ++++++++-----------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/addons/block_code/code_generation/blocks_catalog.gd b/addons/block_code/code_generation/blocks_catalog.gd
index 6fd38e84..4bc8bb71 100644
--- a/addons/block_code/code_generation/blocks_catalog.gd
+++ b/addons/block_code/code_generation/blocks_catalog.gd
@@ -80,7 +80,6 @@ const _SETTINGS_FOR_CLASS_PROPERTY = {
 }
 
 static var _catalog: Dictionary
-static var _by_class_name: Dictionary
 
 
 static func _setup_definitions_from_files():
@@ -91,9 +90,6 @@ static func _setup_definitions_from_files():
 		var target = block_definition.target_node_class
 		if not target:
 			continue
-		if not target in _by_class_name:
-			_by_class_name[target] = {}
-		_by_class_name[target][block_definition.name] = block_definition
 
 
 static func _add_property_definitions(_class_name: String, property_list: Array[Dictionary], property_settings: Dictionary):
@@ -103,9 +99,6 @@ static func _add_property_definitions(_class_name: String, property_list: Array[
 		var block_settings = property_settings[property.name]
 		var type_string: String = Types.VARIANT_TYPE_TO_STRING[property.type]
 
-		if not _class_name in _by_class_name:
-			_by_class_name[_class_name] = {}
-
 		# Setter
 		var block_definition: BlockDefinition
 		if block_settings.get("has_setter", true):
@@ -124,7 +117,6 @@ static func _add_property_definitions(_class_name: String, property_list: Array[
 				)
 			)
 			_catalog[block_definition.name] = block_definition
-			_by_class_name[_class_name][block_definition.name] = block_definition
 
 		# Changer
 		if block_settings.get("has_change", true):
@@ -143,7 +135,6 @@ static func _add_property_definitions(_class_name: String, property_list: Array[
 				)
 			)
 			_catalog[block_definition.name] = block_definition
-			_by_class_name[_class_name][block_definition.name] = block_definition
 
 		# Getter
 		block_definition = (
@@ -160,7 +151,6 @@ static func _add_property_definitions(_class_name: String, property_list: Array[
 			)
 		)
 		_catalog[block_definition.name] = block_definition
-		_by_class_name[_class_name][block_definition.name] = block_definition
 
 
 static func _get_inputmap_actions() -> Array[StringName]:
@@ -234,11 +224,19 @@ static func has_block(block_name: StringName):
 	return block_name in _catalog
 
 
-static func get_blocks_by_class(_class_name: String):
-	if not _class_name in _by_class_name:
-		return []
-	var block_definitions = _by_class_name[_class_name] as Dictionary
-	return block_definitions.values()
+static func get_blocks_by_class(_class_name: String) -> Array[BlockDefinition]:
+	var result: Array[BlockDefinition]
+
+	if not _class_name:
+		return result
+
+	result.assign(_catalog.values().filter(_block_definition_has_class_name.bind(_class_name)))
+
+	return result
+
+
+static func _block_definition_has_class_name(block_definition: BlockDefinition, _class_name: String) -> bool:
+	return block_definition.target_node_class == _class_name
 
 
 static func _get_builtin_parents(_class_name: String) -> Array[String]:
@@ -288,12 +286,8 @@ static func add_custom_blocks(
 ):
 	setup()
 
-	if not _class_name in _by_class_name:
-		_by_class_name[_class_name] = {}
-
 	for block_definition in block_definitions:
 		_catalog[block_definition.name] = block_definition
-		_by_class_name[_class_name][block_definition.name] = block_definition
 
 	_add_property_definitions(_class_name, property_list, property_settings)
 

From dc99328d28b94dafc2a835ed90e85f7c85d577b9 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Wed, 28 Aug 2024 17:58:10 -0700
Subject: [PATCH 03/13] BlockDefinition: Support extension scripts

An extension script can implement functions which refine a block's
presentation depending on the current context, such as the node it is
attached to.

https://phabricator.endlessm.com/T35564
---
 addons/block_code/code_generation/block_definition.gd | 10 ++++++++++
 addons/block_code/code_generation/block_extension.gd  |  3 +++
 2 files changed, 13 insertions(+)
 create mode 100644 addons/block_code/code_generation/block_extension.gd

diff --git a/addons/block_code/code_generation/block_definition.gd b/addons/block_code/code_generation/block_definition.gd
index 9f3bbb90..c5b6521f 100644
--- a/addons/block_code/code_generation/block_definition.gd
+++ b/addons/block_code/code_generation/block_definition.gd
@@ -27,6 +27,14 @@ const Types = preload("res://addons/block_code/types/types.gd")
 ## Empty except for blocks that have a defined scope
 @export var scope: String
 
+@export var extension_script: GDScript
+
+var _extension: BlockExtension:
+	get:
+		if _extension == null and extension_script and extension_script.can_instantiate():
+			_extension = extension_script.new()
+		return _extension as BlockExtension
+
 
 func _init(
 	p_name: StringName = &"",
@@ -40,6 +48,7 @@ func _init(
 	p_defaults = {},
 	p_signal_name: String = "",
 	p_scope: String = "",
+	p_extension_script: GDScript = null,
 ):
 	name = p_name
 	target_node_class = p_target_node_class
@@ -52,6 +61,7 @@ func _init(
 	defaults = p_defaults
 	signal_name = p_signal_name
 	scope = p_scope
+	extension_script = p_extension_script
 
 
 func _to_string():
diff --git a/addons/block_code/code_generation/block_extension.gd b/addons/block_code/code_generation/block_extension.gd
new file mode 100644
index 00000000..2a2fef97
--- /dev/null
+++ b/addons/block_code/code_generation/block_extension.gd
@@ -0,0 +1,3 @@
+@tool
+class_name BlockExtension
+extends Object

From 3517792376dc1b79519f6b58a82a5074ceb5db68 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Wed, 28 Aug 2024 18:05:15 -0700
Subject: [PATCH 04/13] animationplayer_play: Add an extension script to
 generate an option list

This extension customizes the block's "animation" options list using the
list of animations in the block script's context node.

https://phabricator.endlessm.com/T35564
---
 .../blocks/graphics/animationplayer_play.gd       | 15 +++++++++++++++
 .../blocks/graphics/animationplayer_play.tres     | 10 ++++++----
 .../code_generation/block_definition.gd           | 10 ++++++++++
 .../block_code/code_generation/block_extension.gd |  4 ++++
 4 files changed, 35 insertions(+), 4 deletions(-)
 create mode 100644 addons/block_code/blocks/graphics/animationplayer_play.gd

diff --git a/addons/block_code/blocks/graphics/animationplayer_play.gd b/addons/block_code/blocks/graphics/animationplayer_play.gd
new file mode 100644
index 00000000..63c603a2
--- /dev/null
+++ b/addons/block_code/blocks/graphics/animationplayer_play.gd
@@ -0,0 +1,15 @@
+@tool
+extends BlockExtension
+
+const OptionData = preload("res://addons/block_code/code_generation/option_data.gd")
+
+
+func get_defaults_for_node(context_node: Node) -> Dictionary:
+	var animation_player = context_node as AnimationPlayer
+
+	if not animation_player:
+		return {}
+
+	var animation_list = animation_player.get_animation_list()
+
+	return {"animation": OptionData.new(animation_list)}
diff --git a/addons/block_code/blocks/graphics/animationplayer_play.tres b/addons/block_code/blocks/graphics/animationplayer_play.tres
index 2a2f373f..7868406a 100644
--- a/addons/block_code/blocks/graphics/animationplayer_play.tres
+++ b/addons/block_code/blocks/graphics/animationplayer_play.tres
@@ -1,7 +1,8 @@
-[gd_resource type="Resource" load_steps=4 format=3 uid="uid://c5e1byehtxwc0"]
+[gd_resource type="Resource" load_steps=5 format=3 uid="uid://c5e1byehtxwc0"]
 
 [ext_resource type="Script" path="res://addons/block_code/code_generation/block_definition.gd" id="1_emeuv"]
 [ext_resource type="Script" path="res://addons/block_code/code_generation/option_data.gd" id="1_xu43h"]
+[ext_resource type="Script" path="res://addons/block_code/blocks/graphics/animationplayer_play.gd" id="2_7ymgi"]
 
 [sub_resource type="Resource" id="Resource_vnp2w"]
 script = ExtResource("1_xu43h")
@@ -16,14 +17,15 @@ description = "Play the animation."
 category = "Graphics | Animation"
 type = 2
 variant_type = 0
-display_template = "Play {animation: STRING} {direction: OPTION}"
+display_template = "Play {animation: OPTION} {direction: OPTION}"
 code_template = "if \"{direction}\" == \"ahead\":
-	play({animation})
+	play(\"{animation}\")
 else:
-	play_backwards({animation})
+	play_backwards(\"{animation}\")
 "
 defaults = {
 "direction": SubResource("Resource_vnp2w")
 }
 signal_name = ""
 scope = ""
+extension_script = ExtResource("2_7ymgi")
diff --git a/addons/block_code/code_generation/block_definition.gd b/addons/block_code/code_generation/block_definition.gd
index c5b6521f..d1bb05a1 100644
--- a/addons/block_code/code_generation/block_definition.gd
+++ b/addons/block_code/code_generation/block_definition.gd
@@ -64,5 +64,15 @@ func _init(
 	extension_script = p_extension_script
 
 
+func get_defaults_for_node(parent_node: Node) -> Dictionary:
+	if not _extension:
+		return defaults
+
+	# Use Dictionary.merge instead of Dictionary.merged for Godot 4.2 compatibility
+	var new_defaults := _extension.get_defaults_for_node(parent_node)
+	new_defaults.merge(defaults)
+	return new_defaults
+
+
 func _to_string():
 	return "%s - %s" % [name, target_node_class]
diff --git a/addons/block_code/code_generation/block_extension.gd b/addons/block_code/code_generation/block_extension.gd
index 2a2fef97..3e68a312 100644
--- a/addons/block_code/code_generation/block_extension.gd
+++ b/addons/block_code/code_generation/block_extension.gd
@@ -1,3 +1,7 @@
 @tool
 class_name BlockExtension
 extends Object
+
+
+func get_defaults_for_node(context_node: Node) -> Dictionary:
+	return {}

From 81b645679afa9c0710167e6de358efae7c8e7f04 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Tue, 3 Sep 2024 18:00:04 -0700
Subject: [PATCH 05/13] Add TemplateEditor to generate UI based on a block
 format string

This new component replaces StatementBlock.format_string in favour of a
more declarative API.

https://phabricator.endlessm.com/T35564
---
 .../code_generation/block_definition.gd       |  53 +++++++
 .../ui/block_canvas/block_canvas.gd           |  44 +++---
 addons/block_code/ui/blocks/block/block.gd    |  33 ++++-
 .../ui/blocks/control_block/control_block.gd  |  20 +--
 .../blocks/control_block/control_block.tscn   |  11 +-
 .../ui/blocks/entry_block/entry_block.tscn    |  12 +-
 .../blocks/parameter_block/parameter_block.gd |  17 +--
 .../parameter_block/parameter_block.tscn      |  18 +--
 .../blocks/statement_block/statement_block.gd |  96 +------------
 .../statement_block/statement_block.tscn      |  12 +-
 .../parameter_input/parameter_input.gd        |  55 ++++----
 .../parameter_input/parameter_input.tscn      |  27 ++--
 .../parameter_output/parameter_output.gd      |   9 +-
 .../parameter_output/parameter_output.tscn    |   4 +-
 .../blocks/utilities/snap_point/snap_point.gd |  10 ++
 .../template_editor/template_editor.gd        | 132 ++++++++++++++++++
 .../template_editor/template_editor.tscn      |  17 +++
 17 files changed, 354 insertions(+), 216 deletions(-)
 create mode 100644 addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
 create mode 100644 addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn

diff --git a/addons/block_code/code_generation/block_definition.gd b/addons/block_code/code_generation/block_definition.gd
index d1bb05a1..fe36c001 100644
--- a/addons/block_code/code_generation/block_definition.gd
+++ b/addons/block_code/code_generation/block_definition.gd
@@ -4,6 +4,8 @@ extends Resource
 
 const Types = preload("res://addons/block_code/types/types.gd")
 
+const FORMAT_STRING_PATTERN = "\\[(?<out_parameter>[^\\]]+)\\]|\\{(?<in_parameter>[^}]+)\\}|(?<label>[^\\{\\[]+)"
+
 @export var name: StringName
 
 ## The target node. Leaving this empty the block is considered a general block
@@ -29,6 +31,8 @@ const Types = preload("res://addons/block_code/types/types.gd")
 
 @export var extension_script: GDScript
 
+static var _display_template_regex := RegEx.create_from_string(FORMAT_STRING_PATTERN)
+
 var _extension: BlockExtension:
 	get:
 		if _extension == null and extension_script and extension_script.can_instantiate():
@@ -76,3 +80,52 @@ func get_defaults_for_node(parent_node: Node) -> Dictionary:
 
 func _to_string():
 	return "%s - %s" % [name, target_node_class]
+
+
+func get_output_parameters() -> Dictionary:
+	var result: Dictionary
+	for item in parse_display_template(display_template):
+		if item.has("out_parameter"):
+			var parameter = item.get("out_parameter")
+			result[parameter["name"]] = parameter["type"]
+	return result
+
+
+static func parse_display_template(template_string: String):
+	var items: Array[Dictionary]
+	for regex_match in _display_template_regex.search_all(template_string):
+		if regex_match.names.has("label"):
+			var label_string := regex_match.get_string("label")
+			items.append({"label": label_string})
+		elif regex_match.names.has("in_parameter"):
+			var parameter_string := regex_match.get_string("in_parameter")
+			items.append({"in_parameter": _parse_parameter_format(parameter_string)})
+		elif regex_match.names.has("out_parameter"):
+			var parameter_string := regex_match.get_string("out_parameter")
+			items.append({"out_parameter": _parse_parameter_format(parameter_string)})
+	return items
+
+
+static func _parse_parameter_format(parameter_format: String) -> Dictionary:
+	var parameter_name: String
+	var parameter_type_str: String
+	var parameter_type: Variant.Type
+	var split := parameter_format.split(":", true, 1)
+
+	if len(split) == 0:
+		return {}
+
+	if len(split) > 0:
+		parameter_name = split[0].strip_edges()
+
+	if len(split) > 1:
+		parameter_type_str = split[1].strip_edges()
+
+	if parameter_type_str:
+		parameter_type = Types.STRING_TO_VARIANT_TYPE[parameter_type_str]
+
+	return {"name": parameter_name, "type": parameter_type}
+
+
+static func has_category(block_definition, category: String) -> bool:
+	return block_definition.category == category
diff --git a/addons/block_code/ui/block_canvas/block_canvas.gd b/addons/block_code/ui/block_canvas/block_canvas.gd
index 34b1c3e8..cd67f309 100644
--- a/addons/block_code/ui/block_canvas/block_canvas.gd
+++ b/addons/block_code/ui/block_canvas/block_canvas.gd
@@ -153,13 +153,17 @@ func ui_tree_from_ast_node(ast_node: BlockAST.ASTNode) -> Block:
 	var block: Block = _context.block_script.instantiate_block(ast_node.data)
 
 	# Args
+	var parameter_values: Dictionary
+
 	for arg_name in ast_node.arguments:
 		var argument = ast_node.arguments[arg_name]
 		if argument is BlockAST.ASTValueNode:
 			var value_block = ui_tree_from_ast_value_node(argument)
-			block.args_to_add_after_format[arg_name] = value_block
+			parameter_values[arg_name] = value_block
 		else:  # Argument is not a node, but a user input value
-			block.args_to_add_after_format[arg_name] = argument
+			parameter_values[arg_name] = argument
+
+	block.set_parameter_values_on_ready(parameter_values)
 
 	# Children
 	var current_block: Block = block
@@ -184,13 +188,17 @@ func ui_tree_from_ast_value_node(ast_value_node: BlockAST.ASTValueNode) -> Block
 	var block: Block = _context.block_script.instantiate_block(ast_value_node.data)
 
 	# Args
+	var parameter_values: Dictionary
+
 	for arg_name in ast_value_node.arguments:
 		var argument = ast_value_node.arguments[arg_name]
 		if argument is BlockAST.ASTValueNode:
 			var value_block = ui_tree_from_ast_value_node(argument)
-			block.args_to_add_after_format[arg_name] = value_block
+			parameter_values[arg_name] = value_block
 		else:  # Argument is not a node, but a user input value
-			block.args_to_add_after_format[arg_name] = argument
+			parameter_values[arg_name] = argument
+
+	block.set_parameter_values_on_ready(parameter_values)
 
 	reconnect_block.emit(block)
 	return block
@@ -217,14 +225,14 @@ func build_ast(block: Block) -> BlockAST.ASTNode:
 	var ast_node := BlockAST.ASTNode.new()
 	ast_node.data = block.definition
 
-	for arg_name in block.arg_name_to_param_input_dict:
-		var param_input = block.arg_name_to_param_input_dict[arg_name]
-		var snap_point = param_input.snap_point
-		var snapped_block = snap_point.get_snapped_block()
-		if snapped_block:
-			ast_node.arguments[arg_name] = build_value_ast(snapped_block)
+	var parameter_values := block.get_parameter_values()
+
+	for arg_name in parameter_values:
+		var arg_value = parameter_values[arg_name]
+		if arg_value is Block:
+			ast_node.arguments[arg_name] = build_value_ast(arg_value)
 		else:
-			ast_node.arguments[arg_name] = param_input.get_raw_input()
+			ast_node.arguments[arg_name] = arg_value
 
 	var children: Array[BlockAST.ASTNode] = []
 
@@ -250,14 +258,14 @@ func build_value_ast(block: ParameterBlock) -> BlockAST.ASTValueNode:
 	var ast_node := BlockAST.ASTValueNode.new()
 	ast_node.data = block.definition
 
-	for arg_name in block.arg_name_to_param_input_dict:
-		var param_input = block.arg_name_to_param_input_dict[arg_name]
-		var snap_point = param_input.snap_point
-		var snapped_block = snap_point.get_snapped_block()
-		if snapped_block:
-			ast_node.arguments[arg_name] = build_value_ast(snapped_block)
+	var parameter_values := block.get_parameter_values()
+
+	for arg_name in parameter_values:
+		var arg_value = parameter_values[arg_name]
+		if arg_value is Block:
+			ast_node.arguments[arg_name] = build_value_ast(arg_value)
 		else:
-			ast_node.arguments[arg_name] = param_input.get_raw_input()
+			ast_node.arguments[arg_name] = arg_value
 
 	return ast_node
 
diff --git a/addons/block_code/ui/blocks/block/block.gd b/addons/block_code/ui/blocks/block/block.gd
index 499927ca..fcd99cc8 100644
--- a/addons/block_code/ui/blocks/block/block.gd
+++ b/addons/block_code/ui/blocks/block/block.gd
@@ -20,6 +20,9 @@ signal modified
 ## Snap point that holds blocks that should be nested under this block
 @export var child_snap: SnapPoint = null
 
+## The resource containing the definition of the block
+@export var template_editor: TemplateEditor = null
+
 ## The scope of the block (statement of matching entry block)
 @export var scope: String = ""
 
@@ -29,10 +32,34 @@ signal modified
 ## Whether the block can be deleted by the Delete key.
 var can_delete: bool = true
 
+@onready var _context := BlockEditorContext.get_default()
+
 
 func _ready():
 	focus_mode = FocusMode.FOCUS_ALL
 	mouse_filter = Control.MOUSE_FILTER_IGNORE
+	_update_template_editor()
+
+
+func set_parameter_values_on_ready(raw_values: Dictionary):
+	await ready
+	set_parameter_values(raw_values)
+
+
+func set_parameter_values(raw_values: Dictionary):
+	template_editor.set_parameter_values(raw_values)
+
+
+func get_parameter_values() -> Dictionary:
+	return template_editor.get_parameter_values()
+
+
+func _update_template_editor():
+	if template_editor == null:
+		return
+
+	template_editor.format_string = definition.display_template if definition else ""
+	template_editor.parameter_defaults = definition.get_defaults_for_node(_context.parent_node) if definition else {}
 
 
 func _gui_input(event):
@@ -57,6 +84,10 @@ func _gui_input(event):
 			EditorInterface.popup_dialog_centered(dialog)
 
 
+func _modified():
+	modified.emit()
+
+
 func remove_from_tree():
 	var parent = get_parent()
 	if parent:
@@ -84,7 +115,7 @@ func disconnect_signals():
 
 
 func _to_string():
-	return "<{block_class}:{block_name}#{rid}>".format({"block_name": definition.name, "block_class": get_block_class(), "rid": get_instance_id()})
+	return "<{block_class}:{block_name}#{rid}>".format({"block_name": definition.name if definition else "", "block_class": get_block_class(), "rid": get_instance_id()})
 
 
 func _make_custom_tooltip(for_text) -> Control:
diff --git a/addons/block_code/ui/blocks/control_block/control_block.gd b/addons/block_code/ui/blocks/control_block/control_block.gd
index c4d4590b..4d1a8dbb 100644
--- a/addons/block_code/ui/blocks/control_block/control_block.gd
+++ b/addons/block_code/ui/blocks/control_block/control_block.gd
@@ -3,9 +3,9 @@ class_name ControlBlock
 extends Block
 
 const Constants = preload("res://addons/block_code/ui/constants.gd")
-
-var arg_name_to_param_input_dict: Dictionary
-var args_to_add_after_format: Dictionary  # Only used when loading
+const DragDropArea = preload("res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.gd")
+const DragDropAreaScene = preload("res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.tscn")
+const Gutter = preload("res://addons/block_code/ui/blocks/utilities/background/gutter.gd")
 
 
 func _ready():
@@ -19,16 +19,6 @@ func _ready():
 	%SnapGutter.color = color
 	%SnapGutter.custom_minimum_size.x = Constants.CONTROL_MARGIN
 
-	format()
-
-	for arg_name in arg_name_to_param_input_dict:
-		if arg_name in args_to_add_after_format:
-			var argument = args_to_add_after_format[arg_name]
-			if argument is Block:
-				arg_name_to_param_input_dict[arg_name].snap_point.add_child(argument)
-			else:
-				arg_name_to_param_input_dict[arg_name].set_raw_input(argument)
-
 
 func _on_drag_drop_area_mouse_down():
 	_drag_started()
@@ -40,7 +30,3 @@ static func get_block_class():
 
 static func get_scene_path():
 	return "res://addons/block_code/ui/blocks/control_block/control_block.tscn"
-
-
-func format():
-	arg_name_to_param_input_dict = StatementBlock.format_string(self, %RowHBox, definition.display_template, definition.defaults)
diff --git a/addons/block_code/ui/blocks/control_block/control_block.tscn b/addons/block_code/ui/blocks/control_block/control_block.tscn
index 947b8d25..adb481e2 100644
--- a/addons/block_code/ui/blocks/control_block/control_block.tscn
+++ b/addons/block_code/ui/blocks/control_block/control_block.tscn
@@ -1,18 +1,20 @@
-[gd_scene load_steps=6 format=3 uid="uid://bk2argmujy0kk"]
+[gd_scene load_steps=7 format=3 uid="uid://bk2argmujy0kk"]
 
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/control_block/control_block.gd" id="1_2hbir"]
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/utilities/background/gutter.gd" id="2_6o8pf"]
 [ext_resource type="PackedScene" uid="uid://c7puyxpqcq6xo" path="res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.tscn" id="2_lpu3c"]
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/utilities/background/background.gd" id="2_tx0qr"]
 [ext_resource type="PackedScene" uid="uid://b1oge52xhjqnu" path="res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.tscn" id="3_nhryi"]
+[ext_resource type="PackedScene" uid="uid://b1xvp3u11h41s" path="res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn" id="4_6uktl"]
 
-[node name="ControlBlock" type="MarginContainer" node_paths=PackedStringArray("bottom_snap", "child_snap")]
+[node name="ControlBlock" type="MarginContainer" node_paths=PackedStringArray("bottom_snap", "child_snap", "template_editor")]
 size_flags_horizontal = 0
 focus_mode = 2
 mouse_filter = 2
 script = ExtResource("1_2hbir")
 bottom_snap = NodePath("VBoxContainer/SnapPoint")
 child_snap = NodePath("VBoxContainer/MarginContainer/Rows/SnapContainer/SnapPoint")
+template_editor = NodePath("VBoxContainer/MarginContainer/Rows/Row/RowHBoxContainer/TemplateEditor")
 
 [node name="VBoxContainer" type="VBoxContainer" parent="."]
 layout_mode = 2
@@ -57,11 +59,9 @@ theme_override_constants/margin_top = 6
 theme_override_constants/margin_right = 12
 theme_override_constants/margin_bottom = 6
 
-[node name="RowHBox" type="HBoxContainer" parent="VBoxContainer/MarginContainer/Rows/Row/RowHBoxContainer"]
+[node name="TemplateEditor" parent="VBoxContainer/MarginContainer/Rows/Row/RowHBoxContainer" instance=ExtResource("4_6uktl")]
 unique_name_in_owner = true
 layout_mode = 2
-mouse_filter = 2
-theme_override_constants/separation = 0
 
 [node name="SnapContainer" type="MarginContainer" parent="VBoxContainer/MarginContainer/Rows"]
 unique_name_in_owner = true
@@ -95,4 +95,5 @@ shift_top = 20.0
 [node name="SnapPoint" parent="VBoxContainer" instance=ExtResource("3_nhryi")]
 layout_mode = 2
 
+[connection signal="modified" from="." to="." method="_modified"]
 [connection signal="mouse_down" from="VBoxContainer/MarginContainer/Rows/Row/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
diff --git a/addons/block_code/ui/blocks/entry_block/entry_block.tscn b/addons/block_code/ui/blocks/entry_block/entry_block.tscn
index 9318bf94..fcb8b6a7 100644
--- a/addons/block_code/ui/blocks/entry_block/entry_block.tscn
+++ b/addons/block_code/ui/blocks/entry_block/entry_block.tscn
@@ -1,16 +1,18 @@
-[gd_scene load_steps=5 format=3 uid="uid://d2fibflv3ojys"]
+[gd_scene load_steps=6 format=3 uid="uid://d2fibflv3ojys"]
 
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/entry_block/entry_block.gd" id="2_3ik8h"]
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/utilities/background/background.gd" id="2_yrw8l"]
 [ext_resource type="PackedScene" uid="uid://c7puyxpqcq6xo" path="res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.tscn" id="3_v0qw8"]
+[ext_resource type="PackedScene" uid="uid://b1xvp3u11h41s" path="res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn" id="4_1gwsm"]
 [ext_resource type="PackedScene" uid="uid://b1oge52xhjqnu" path="res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.tscn" id="4_yj206"]
 
-[node name="EntryBlock" type="MarginContainer" node_paths=PackedStringArray("child_snap")]
+[node name="EntryBlock" type="MarginContainer" node_paths=PackedStringArray("child_snap", "template_editor")]
 size_flags_horizontal = 0
 focus_mode = 2
 mouse_filter = 2
 script = ExtResource("2_3ik8h")
 child_snap = NodePath("VBoxContainer/SnapPoint")
+template_editor = NodePath("VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor")
 
 [node name="VBoxContainer" type="VBoxContainer" parent="."]
 layout_mode = 2
@@ -46,14 +48,12 @@ theme_override_constants/margin_top = 6
 theme_override_constants/margin_right = 12
 theme_override_constants/margin_bottom = 6
 
-[node name="HBoxContainer" type="HBoxContainer" parent="VBoxContainer/TopMarginContainer/MarginContainer"]
+[node name="TemplateEditor" parent="VBoxContainer/TopMarginContainer/MarginContainer" instance=ExtResource("4_1gwsm")]
 unique_name_in_owner = true
-custom_minimum_size = Vector2(50, 0)
 layout_mode = 2
-mouse_filter = 2
-theme_override_constants/separation = 0
 
 [node name="SnapPoint" parent="VBoxContainer" instance=ExtResource("4_yj206")]
 layout_mode = 2
 
 [connection signal="mouse_down" from="VBoxContainer/TopMarginContainer/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
+[connection signal="modified" from="VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor" to="." method="_modified"]
diff --git a/addons/block_code/ui/blocks/parameter_block/parameter_block.gd b/addons/block_code/ui/blocks/parameter_block/parameter_block.gd
index 2ed56aca..f29c910d 100644
--- a/addons/block_code/ui/blocks/parameter_block/parameter_block.gd
+++ b/addons/block_code/ui/blocks/parameter_block/parameter_block.gd
@@ -4,11 +4,10 @@ extends Block
 
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 const Util = preload("res://addons/block_code/ui/util.gd")
+const ParameterOutput = preload("res://addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd")
 
 @onready var _panel := $Panel
-@onready var _hbox := %HBoxContainer
 
-var arg_name_to_param_input_dict: Dictionary
 var args_to_add_after_format: Dictionary  # Only used when loading
 var spawned_by: ParameterOutput
 
@@ -30,16 +29,6 @@ func _ready():
 	if not Util.node_is_part_of_edited_scene(self):
 		_panel.add_theme_stylebox_override("panel", _panel_normal)
 
-	format()
-
-	for arg_name in arg_name_to_param_input_dict:
-		if arg_name in args_to_add_after_format:
-			var argument = args_to_add_after_format[arg_name]
-			if argument is Block:
-				arg_name_to_param_input_dict[arg_name].snap_point.add_child(argument)
-			else:
-				arg_name_to_param_input_dict[arg_name].set_raw_input(argument)
-
 
 func _on_drag_drop_area_mouse_down():
 	_drag_started()
@@ -53,10 +42,6 @@ static func get_scene_path():
 	return "res://addons/block_code/ui/blocks/parameter_block/parameter_block.tscn"
 
 
-func format():
-	arg_name_to_param_input_dict = StatementBlock.format_string(self, %HBoxContainer, definition.display_template, definition.defaults)
-
-
 func _on_focus_entered():
 	_panel.add_theme_stylebox_override("panel", _panel_focus)
 
diff --git a/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn b/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
index ac46b80a..921f9652 100644
--- a/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
+++ b/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
@@ -1,7 +1,8 @@
-[gd_scene load_steps=4 format=3 uid="uid://clipm2dd28jde"]
+[gd_scene load_steps=5 format=3 uid="uid://clipm2dd28jde"]
 
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/parameter_block/parameter_block.gd" id="1_0hajy"]
 [ext_resource type="PackedScene" uid="uid://c7puyxpqcq6xo" path="res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.tscn" id="2_gy5co"]
+[ext_resource type="PackedScene" uid="uid://b1xvp3u11h41s" path="res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn" id="3_shl1a"]
 
 [sub_resource type="StyleBoxFlat" id="StyleBoxFlat_dbera"]
 bg_color = Color(1, 1, 1, 1)
@@ -14,13 +15,14 @@ corner_radius_top_right = 16
 corner_radius_bottom_right = 16
 corner_radius_bottom_left = 16
 
-[node name="ParameterBlock" type="MarginContainer"]
+[node name="ParameterBlock" type="MarginContainer" node_paths=PackedStringArray("template_editor")]
 offset_right = 16.0
 offset_bottom = 8.0
 size_flags_horizontal = 0
 focus_mode = 2
 mouse_filter = 2
 script = ExtResource("1_0hajy")
+template_editor = NodePath("MarginContainer/TemplateEditor")
 
 [node name="Panel" type="Panel" parent="."]
 unique_name_in_owner = true
@@ -32,18 +34,18 @@ layout_mode = 2
 
 [node name="MarginContainer" type="MarginContainer" parent="."]
 layout_mode = 2
-size_flags_horizontal = 0
 mouse_filter = 2
+
+[node name="TemplateEditor" parent="MarginContainer" instance=ExtResource("3_shl1a")]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 0
 theme_override_constants/margin_left = 10
 theme_override_constants/margin_top = 8
 theme_override_constants/margin_right = 10
 theme_override_constants/margin_bottom = 8
 
-[node name="HBoxContainer" type="HBoxContainer" parent="MarginContainer"]
-unique_name_in_owner = true
-layout_mode = 2
-mouse_filter = 2
-
 [connection signal="focus_entered" from="." to="." method="_on_focus_entered"]
 [connection signal="focus_exited" from="." to="." method="_on_focus_exited"]
 [connection signal="mouse_down" from="DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
+[connection signal="modified" from="MarginContainer/TemplateEditor" to="." method="_modified"]
diff --git a/addons/block_code/ui/blocks/statement_block/statement_block.gd b/addons/block_code/ui/blocks/statement_block/statement_block.gd
index 5340477d..3cea5484 100644
--- a/addons/block_code/ui/blocks/statement_block/statement_block.gd
+++ b/addons/block_code/ui/blocks/statement_block/statement_block.gd
@@ -2,7 +2,6 @@
 class_name StatementBlock
 extends Block
 
-const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_catalog.gd")
 const ParameterInput = preload("res://addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd")
 const ParameterInputScene = preload("res://addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn")
 const ParameterOutput = preload("res://addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd")
@@ -10,7 +9,6 @@ const ParameterOutputScene = preload("res://addons/block_code/ui/blocks/utilitie
 const Types = preload("res://addons/block_code/types/types.gd")
 
 @onready var _background := %Background
-@onready var _hbox := %HBoxContainer
 
 var arg_name_to_param_input_dict: Dictionary
 var args_to_add_after_format: Dictionary  # Only used when loading
@@ -19,20 +17,10 @@ var args_to_add_after_format: Dictionary  # Only used when loading
 func _ready():
 	super()
 
-	if definition.type != Types.BlockType.STATEMENT:
+	if definition != null and definition.type != Types.BlockType.STATEMENT:
 		_background.show_top = false
 	_background.color = color
 
-	format()
-
-	for arg_name in arg_name_to_param_input_dict:
-		if arg_name in args_to_add_after_format:
-			var argument = args_to_add_after_format[arg_name]
-			if argument is Block:
-				arg_name_to_param_input_dict[arg_name].snap_point.add_child(argument)
-			else:
-				arg_name_to_param_input_dict[arg_name].set_raw_input(argument)
-
 
 func _on_drag_drop_area_mouse_down():
 	_drag_started()
@@ -44,85 +32,3 @@ static func get_block_class():
 
 static func get_scene_path():
 	return "res://addons/block_code/ui/blocks/statement_block/statement_block.tscn"
-
-
-func format():
-	arg_name_to_param_input_dict = format_string(self, %HBoxContainer, definition.display_template, definition.defaults)
-
-
-static func format_string(parent_block: Block, attach_to: Node, string: String, _defaults: Dictionary) -> Dictionary:
-	BlocksCatalog.setup()
-	var _arg_name_to_param_input_dict = {}
-	var regex = RegEx.new()
-	regex.compile("\\[([^\\]]+)\\]|\\{([^}]+)\\}")  # Capture things of format {test} or [test]
-	var results := regex.search_all(string)
-
-	var start: int = 0
-	for result in results:
-		var label_text := string.substr(start, result.get_start() - start)
-		if label_text != "":
-			var label = Label.new()
-			label.add_theme_color_override("font_color", Color.WHITE)
-			label.text = label_text
-			attach_to.add_child(label)
-
-		var param := result.get_string()
-		var copy_block: bool = param[0] == "["
-		param = param.substr(1, param.length() - 2)
-
-		var split := param.split(": ")
-		var param_name := split[0]
-		var param_type_str := split[1]
-
-		var param_type = null
-		var option := false
-		if param_type_str == "OPTION":  # Easy way to specify dropdown option
-			option = true
-		else:
-			param_type = Types.STRING_TO_VARIANT_TYPE[param_type_str]
-
-		var param_default = null
-		if _defaults.has(param_name):
-			param_default = _defaults[param_name]
-
-		var param_node: Node
-
-		if copy_block:
-			var parameter_output: ParameterOutput = ParameterOutputScene.instantiate()
-			parameter_output.name = "ParameterOutput%d" % start  # Unique path
-
-			var block_name = &"%s_%s" % [parent_block.definition.name, param_name]
-			var block_definition = BlocksCatalog.get_block(block_name)
-			if block_definition == null:
-				push_error("Could not locate block definition %s" % block_name)
-
-			parameter_output.block_params = {"definition": block_definition, "color": parent_block.color}
-			parameter_output.block = parent_block
-			attach_to.add_child(parameter_output)
-		else:
-			var parameter_input: ParameterInput = ParameterInputScene.instantiate()
-			parameter_input.name = "ParameterInput%d" % start  # Unique path
-			parameter_input.placeholder = param_name
-			if param_type != null:
-				parameter_input.variant_type = param_type
-			elif option:
-				parameter_input.option = true
-			parameter_input.modified.connect(func(): parent_block.modified.emit())
-
-			attach_to.add_child(parameter_input)
-
-			if param_default != null:
-				parameter_input.set_raw_input(param_default)
-
-			_arg_name_to_param_input_dict[param_name] = parameter_input
-
-		start = result.get_end()
-
-	var label_text := string.substr(start)
-	if label_text != "":
-		var label = Label.new()
-		label.add_theme_color_override("font_color", Color.WHITE)
-		label.text = label_text
-		attach_to.add_child(label)
-
-	return _arg_name_to_param_input_dict
diff --git a/addons/block_code/ui/blocks/statement_block/statement_block.tscn b/addons/block_code/ui/blocks/statement_block/statement_block.tscn
index 90bbdd9c..164f8b21 100644
--- a/addons/block_code/ui/blocks/statement_block/statement_block.tscn
+++ b/addons/block_code/ui/blocks/statement_block/statement_block.tscn
@@ -1,16 +1,18 @@
-[gd_scene load_steps=5 format=3 uid="uid://c84vmg3odrtxt"]
+[gd_scene load_steps=6 format=3 uid="uid://c84vmg3odrtxt"]
 
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/statement_block/statement_block.gd" id="1_6wvlf"]
 [ext_resource type="Script" path="res://addons/block_code/ui/blocks/utilities/background/background.gd" id="2_lctqt"]
 [ext_resource type="PackedScene" uid="uid://c7puyxpqcq6xo" path="res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.tscn" id="2_owgdx"]
 [ext_resource type="PackedScene" uid="uid://b1oge52xhjqnu" path="res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.tscn" id="3_5vaov"]
+[ext_resource type="PackedScene" uid="uid://b1xvp3u11h41s" path="res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn" id="4_vky23"]
 
-[node name="StatementBlock" type="MarginContainer" node_paths=PackedStringArray("bottom_snap")]
+[node name="StatementBlock" type="MarginContainer" node_paths=PackedStringArray("bottom_snap", "template_editor")]
 size_flags_horizontal = 0
 focus_mode = 2
 mouse_filter = 2
 script = ExtResource("1_6wvlf")
 bottom_snap = NodePath("VBoxContainer/SnapPoint")
+template_editor = NodePath("VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor")
 
 [node name="VBoxContainer" type="VBoxContainer" parent="."]
 layout_mode = 2
@@ -45,14 +47,12 @@ theme_override_constants/margin_top = 6
 theme_override_constants/margin_right = 12
 theme_override_constants/margin_bottom = 6
 
-[node name="HBoxContainer" type="HBoxContainer" parent="VBoxContainer/TopMarginContainer/MarginContainer"]
+[node name="TemplateEditor" parent="VBoxContainer/TopMarginContainer/MarginContainer" instance=ExtResource("4_vky23")]
 unique_name_in_owner = true
-custom_minimum_size = Vector2(50, 0)
 layout_mode = 2
-mouse_filter = 2
-theme_override_constants/separation = 0
 
 [node name="SnapPoint" parent="VBoxContainer" instance=ExtResource("3_5vaov")]
 layout_mode = 2
 
 [connection signal="mouse_down" from="VBoxContainer/TopMarginContainer/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
+[connection signal="modified" from="VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor" to="." method="_modified"]
diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
index 7dc719d5..91d1a496 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
@@ -1,7 +1,6 @@
 @tool
 extends MarginContainer
 
-const OptionData = preload("res://addons/block_code/code_generation/option_data.gd")
 const Types = preload("res://addons/block_code/types/types.gd")
 
 signal modified
@@ -13,6 +12,7 @@ signal modified
 @export var block_type: Types.BlockType = Types.BlockType.VALUE
 var option: bool = false:
 	set = _set_option
+var default_value: Variant
 
 @onready var _panel := %Panel
 @onready var snap_point := %SnapPoint
@@ -36,22 +36,20 @@ var option: bool = false:
 
 # Used to submit the text when losing focus:
 @onready var _last_submitted_text = {
-	_line_edit: _line_edit.text,
-	_x_line_edit: _x_line_edit.text,
-	_y_line_edit: _y_line_edit.text,
+	_line_edit: "",
+	_x_line_edit: "",
+	_y_line_edit: "",
 }
 
 
-func set_raw_input(raw_input):
-	if option:
-		_panel.visible = false
-		_option_input.clear()
-		var option_data: OptionData = raw_input as OptionData
-		for item in option_data.items:
-			_option_input.add_item(item.capitalize())
-		_option_input.select(option_data.selected)
-
-		return
+## Sets the value using [param raw_input], which could be one of a variety of types
+## depending on [member variant_type]. The value could also be a [Block], in which
+## case the block will be snapped to the control, replacing its editor.
+func set_raw_input(raw_input: Variant):
+	if raw_input is Block:
+		snap_point.replace_snapped_block(raw_input)
+		# Continue from here to reset the editor to default values
+		raw_input = null
 
 	match variant_type:
 		TYPE_COLOR:
@@ -59,22 +57,28 @@ func set_raw_input(raw_input):
 			_update_panel_bg_color(raw_input)
 		TYPE_VECTOR2:
 			# Rounding because floats are doubles by default but Vector2s have single components
-			_x_line_edit.text = ("%.4f" % raw_input.x).rstrip("0").rstrip(".")
-			_y_line_edit.text = ("%.4f" % raw_input.y).rstrip("0").rstrip(".")
+			_x_line_edit.text = ("%.4f" % raw_input.x).rstrip("0").rstrip(".") if raw_input != null else ""
+			_y_line_edit.text = ("%.4f" % raw_input.y).rstrip("0").rstrip(".") if raw_input != null else ""
 		TYPE_BOOL:
 			_bool_input_option.select(raw_input)
 		TYPE_NIL:
-			_line_edit.text = raw_input
+			_line_edit.text = raw_input if raw_input != null else ""
 		_:
-			_line_edit.text = "" if raw_input == null else str(raw_input)
+			_line_edit.text = str(raw_input) if raw_input != null else ""
+
+	_last_submitted_text[_line_edit] = _line_edit.text
+	_last_submitted_text[_x_line_edit] = _x_line_edit.text
+	_last_submitted_text[_y_line_edit] = _y_line_edit.text
 
 
-func get_raw_input():
-	if option:
-		var options: Array = []
-		for i in _option_input.item_count:
-			options.append(_option_input.get_item_text(i).to_snake_case())
-		return OptionData.new(options, _option_input.selected)
+## Gets the value, which could be one of a variety of types depending on
+## [member variant_type]. The value could also be a [Block], if one was previously
+## snapped to the control.
+func get_raw_input() -> Variant:
+	var snapped_block = snap_point.get_snapped_block()
+
+	if snapped_block:
+		return snapped_block
 
 	match variant_type:
 		TYPE_COLOR:
@@ -126,6 +130,9 @@ func _ready():
 
 	_update_visible_input()
 
+	if default_value:
+		set_raw_input(default_value)
+
 
 func get_snapped_block() -> Block:
 	return snap_point.get_snapped_block()
diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
index 4b0b2912..bc65c184 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
@@ -10,12 +10,12 @@ corner_radius_top_right = 40
 corner_radius_bottom_right = 40
 corner_radius_bottom_left = 40
 
-[sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_6oowp"]
-
 [sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_afyv2"]
 
 [sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_3r4mt"]
 
+[sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_6oowp"]
+
 [sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_5hq7f"]
 
 [sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_fjquj"]
@@ -60,13 +60,13 @@ theme_override_constants/margin_bottom = 4
 unique_name_in_owner = true
 layout_mode = 2
 mouse_filter = 1
-theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
-theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
 theme_override_colors/font_placeholder_color = Color(0.76662, 0.76662, 0.76662, 1)
+theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
+theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
 theme_override_constants/minimum_character_width = 0
-theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 theme_override_styles/focus = SubResource("StyleBoxEmpty_afyv2")
 theme_override_styles/read_only = SubResource("StyleBoxEmpty_3r4mt")
+theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 placeholder_text = "Parameter"
 expand_to_text_length = true
 
@@ -106,13 +106,13 @@ size_flags_horizontal = 3
 unique_name_in_owner = true
 layout_mode = 2
 mouse_filter = 1
-theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
-theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
 theme_override_colors/font_placeholder_color = Color(0.76662, 0.76662, 0.76662, 1)
+theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
+theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
 theme_override_constants/minimum_character_width = 0
-theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 theme_override_styles/focus = SubResource("StyleBoxEmpty_afyv2")
 theme_override_styles/read_only = SubResource("StyleBoxEmpty_3r4mt")
+theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 placeholder_text = "x"
 alignment = 1
 expand_to_text_length = true
@@ -139,13 +139,13 @@ size_flags_horizontal = 3
 unique_name_in_owner = true
 layout_mode = 2
 mouse_filter = 1
-theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
-theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
 theme_override_colors/font_placeholder_color = Color(0.76662, 0.76662, 0.76662, 1)
+theme_override_colors/font_uneditable_color = Color(0.117647, 0.117647, 0.117647, 1)
+theme_override_colors/font_color = Color(0.118581, 0.118581, 0.118581, 1)
 theme_override_constants/minimum_character_width = 0
-theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 theme_override_styles/focus = SubResource("StyleBoxEmpty_afyv2")
 theme_override_styles/read_only = SubResource("StyleBoxEmpty_3r4mt")
+theme_override_styles/normal = SubResource("StyleBoxEmpty_6oowp")
 placeholder_text = "y"
 alignment = 1
 expand_to_text_length = true
@@ -164,14 +164,13 @@ theme_override_constants/margin_left = 8
 unique_name_in_owner = true
 custom_minimum_size = Vector2(60, 0)
 layout_mode = 2
-theme_override_colors/font_color = Color(0, 0, 0, 1)
 theme_override_colors/font_focus_color = Color(0, 0, 0, 1)
+theme_override_colors/font_color = Color(0, 0, 0, 1)
 theme_override_styles/focus = SubResource("StyleBoxEmpty_e7f0k")
 theme_override_styles/normal = SubResource("StyleBoxEmpty_fjquj")
-item_count = 2
 selected = 0
+item_count = 2
 popup/item_0/text = "False"
-popup/item_0/id = 0
 popup/item_1/text = "True"
 popup/item_1/id = 1
 
diff --git a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
index 579d3102..0808597e 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
+++ b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd
@@ -1,11 +1,13 @@
 @tool
-class_name ParameterOutput
 extends MarginContainer
 
 const Types = preload("res://addons/block_code/types/types.gd")
+const ParameterBlock = preload("res://addons/block_code/ui/blocks/parameter_block/parameter_block.gd")
+const ParameterBlockScene = preload("res://addons/block_code/ui/blocks/parameter_block/parameter_block.tscn")
 
 var block: Block
 var parameter_name: String
+var output_block: Block
 var _block_name: String:
 	get:
 		return block.definition.name if block else ""
@@ -18,12 +20,13 @@ var _block_name: String:
 
 
 func _ready():
-	_snap_point.block_type = Types.BlockType.NONE
-
 	_update_parameter_block.call_deferred()
 
 
 func _update_parameter_block():
+	if _snap_point == null:
+		return
+
 	if _snap_point.has_snapped_block():
 		return
 
diff --git a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.tscn b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.tscn
index 71889e68..6fab285c 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.tscn
+++ b/addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.tscn
@@ -27,12 +27,10 @@ layout_mode = 2
 mouse_filter = 2
 theme_override_styles/panel = SubResource("StyleBoxFlat_tn6h4")
 
-[node name="SnapPoint" parent="." node_paths=PackedStringArray("snapped_block") instance=ExtResource("2_ngr7c")]
+[node name="SnapPoint" parent="." instance=ExtResource("2_ngr7c")]
 unique_name_in_owner = true
 layout_mode = 2
-mouse_filter = 2
 block_type = 0
-snapped_block = NodePath("ParameterBlock")
 variant_type = 4
 
 [connection signal="child_exiting_tree" from="." to="SnapPoint" method="_on_parameter_output_child_exiting_tree"]
diff --git a/addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd b/addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd
index 6b80f786..0cab0dae 100644
--- a/addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd
+++ b/addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd
@@ -49,6 +49,16 @@ func has_snapped_block() -> bool:
 	return snapped_block != null
 
 
+func replace_snapped_block(new_block: Block):
+	var old_block = get_snapped_block()
+
+	if old_block:
+		remove_child(old_block)
+
+	if new_block:
+		add_child(new_block)
+
+
 func insert_snapped_block(new_block: Block) -> Block:
 	var old_block = get_snapped_block()
 
diff --git a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
new file mode 100644
index 00000000..6b72e0de
--- /dev/null
+++ b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
@@ -0,0 +1,132 @@
+@tool
+class_name TemplateEditor
+extends Container
+
+signal modified
+
+const BlockDefinition = preload("res://addons/block_code/code_generation/block_definition.gd")
+const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
+const OptionData = preload("res://addons/block_code/code_generation/option_data.gd")
+const ParameterInput = preload("res://addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd")
+const ParameterInputScene = preload("res://addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn")
+const ParameterOutput = preload("res://addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.gd")
+const ParameterOutputScene = preload("res://addons/block_code/ui/blocks/utilities/parameter_output/parameter_output.tscn")
+
+const FORMAT_STRING_PATTERN = "\\[(?<out_parameter>[^\\]]+)\\]|\\{(?<in_parameter>[^}]+)\\}|(?<label>[^\\{\\[]+)"
+
+## A string describing a block's display format. For example:
+## [br]
+## [code]
+## Print {text: STRING}
+## [/code]
+## [br]
+## This component's children will be generated based on the format string,
+## with [code]ParameterInput[/code] and [code]ParameterOutput[/code] nodes in
+## place of any parameters of format [code]{foo}[/code] or [code][foo][/code].
+@export var format_string: String:
+	set(value):
+		format_string = value
+		_update_from_format_string()
+
+## A dictionary describing default values for a block's parameters. The keys of
+## the dictionary must match the list of parameters in [param format_string].
+## The values should be the same type as the parameter.
+@export var parameter_defaults: Dictionary:
+	set(value):
+		parameter_defaults = value
+		_update_from_format_string()
+
+var parent_block: Block
+var _parameter_inputs_by_name: Dictionary
+
+@onready var _container := %Container
+@onready var _regex := RegEx.create_from_string(FORMAT_STRING_PATTERN)
+
+
+func _ready() -> void:
+	parent_block = BlockTreeUtil.get_parent_block(self)
+
+	_update_from_format_string()
+
+
+## Set the values of all input parameters based from a dictionary of raw values.
+## Parameters not included in [param raw_values] will be reset to their
+## defaults according to [member parameter_defaults].
+func set_parameter_values(raw_values: Dictionary):
+	for parameter_name in _parameter_inputs_by_name:
+		var parameter_input: ParameterInput = _parameter_inputs_by_name[parameter_name]
+		var parameter_value: Variant = raw_values.get(parameter_name)
+
+		parameter_input.set_raw_input(parameter_value)
+
+
+func get_parameter_values() -> Dictionary:
+	var result: Dictionary
+
+	for parameter_name in _parameter_inputs_by_name:
+		var parameter_input: ParameterInput = _parameter_inputs_by_name[parameter_name]
+		result[parameter_name] = parameter_input.get_raw_input()
+
+	return result
+
+
+func format_statement(statement: String) -> String:
+	return _parameter_inputs_by_name.keys().reduce(_replace_parameter_in_statement, statement)
+
+
+func _replace_parameter_in_statement(statement: String, parameter_name: String) -> String:
+	var parameter_input: ParameterInput = _parameter_inputs_by_name[parameter_name]
+	return statement.replace("{%s}" % parameter_name, parameter_input.get_string())
+
+
+func _update_from_format_string():
+	if not _container:
+		return
+
+	_parameter_inputs_by_name = {}
+	for child in _container.get_children():
+		_container.remove_child(child)
+		child.queue_free()
+
+	var match_id = 0
+	for item in BlockDefinition.parse_display_template(format_string):
+		if item.has("label"):
+			_append_label(item.get("label"))
+		elif item.has("in_parameter"):
+			_append_input_parameter(item.get("in_parameter"), match_id)
+		elif item.has("out_parameter"):
+			_append_output_parameter(item.get("out_parameter"), match_id)
+		match_id += 1
+
+
+func _append_label(label_format: String):
+	var label = Label.new()
+	label.add_theme_color_override("font_color", Color.WHITE)
+	label.text = label_format.strip_edges()
+	_container.add_child(label)
+
+
+func _append_input_parameter(parameter: Dictionary, id: int):
+	var default_value = parameter_defaults.get(parameter["name"])
+
+	var parameter_input: ParameterInput = ParameterInputScene.instantiate()
+	parameter_input.name = "ParameterInput%d" % id
+	parameter_input.placeholder = parameter["name"]
+	parameter_input.variant_type = parameter["type"]
+	parameter_input.option = parameter["is_option"]
+	parameter_input.default_value = default_value
+
+	parameter_input.modified.connect(func(): modified.emit())
+
+	_container.add_child(parameter_input)
+	_parameter_inputs_by_name[parameter["name"]] = parameter_input
+
+
+func _append_output_parameter(parameter: Dictionary, id: int):
+	var parameter_output: ParameterOutput
+
+	parameter_output = ParameterOutputScene.instantiate()
+	parameter_output.name = "ParameterOutput%d" % id
+	parameter_output.block = parent_block
+	parameter_output.parameter_name = parameter["name"]
+	_container.add_child(parameter_output)
diff --git a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn
new file mode 100644
index 00000000..319306d1
--- /dev/null
+++ b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.tscn
@@ -0,0 +1,17 @@
+[gd_scene load_steps=2 format=3 uid="uid://b1xvp3u11h41s"]
+
+[ext_resource type="Script" path="res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd" id="1_7extq"]
+
+[node name="TemplateEditor" type="MarginContainer"]
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+mouse_filter = 2
+script = ExtResource("1_7extq")
+
+[node name="Container" type="HBoxContainer" parent="."]
+unique_name_in_owner = true
+layout_mode = 2
+mouse_filter = 2

From 1d8821c42aa70a5712d2bfed60e6b26d6a781178 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 5 Sep 2024 17:41:27 -0700
Subject: [PATCH 06/13] ParameterInput: Add a separate option data property

Instead of inferring that there is a list of options based on the
current value, ParameterInput expects to be given a list of options,
and get_raw_input and set_raw_input understand that the raw input is a
value from the list.

In addition, change TemplateEditor itself to determine the list of
options for a given parameter. This option data is always from the
parameter_defaults property, regardless of the block's current value.

https://phabricator.endlessm.com/T35564
---
 .../parameter_input/parameter_input.gd        | 78 ++++++++++++++++---
 .../parameter_input/parameter_input.tscn      |  2 +
 .../template_editor/template_editor.gd        | 12 ++-
 3 files changed, 78 insertions(+), 14 deletions(-)

diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
index 91d1a496..dec6ebc6 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
@@ -1,6 +1,7 @@
 @tool
 extends MarginContainer
 
+const OptionData = preload("res://addons/block_code/code_generation/option_data.gd")
 const Types = preload("res://addons/block_code/types/types.gd")
 
 signal modified
@@ -10,8 +11,9 @@ signal modified
 
 @export var variant_type: Variant.Type = TYPE_STRING
 @export var block_type: Types.BlockType = Types.BlockType.VALUE
-var option: bool = false:
-	set = _set_option
+@export var option_data: OptionData:
+	set = _set_option_data
+
 var default_value: Variant
 
 @onready var _panel := %Panel
@@ -51,6 +53,13 @@ func set_raw_input(raw_input: Variant):
 		# Continue from here to reset the editor to default values
 		raw_input = null
 
+	if option_data:
+		_update_option_input(raw_input)
+		return
+
+	if raw_input == null:
+		raw_input = default_value
+
 	match variant_type:
 		TYPE_COLOR:
 			_color_input.color = raw_input
@@ -60,7 +69,7 @@ func set_raw_input(raw_input: Variant):
 			_x_line_edit.text = ("%.4f" % raw_input.x).rstrip("0").rstrip(".") if raw_input != null else ""
 			_y_line_edit.text = ("%.4f" % raw_input.y).rstrip("0").rstrip(".") if raw_input != null else ""
 		TYPE_BOOL:
-			_bool_input_option.select(raw_input)
+			_bool_input_option.select(1 if raw_input else 0)
 		TYPE_NIL:
 			_line_edit.text = raw_input if raw_input != null else ""
 		_:
@@ -80,6 +89,9 @@ func get_raw_input() -> Variant:
 	if snapped_block:
 		return snapped_block
 
+	if option_data:
+		return _option_input.get_selected_metadata()
+
 	match variant_type:
 		TYPE_COLOR:
 			return _color_input.color
@@ -99,23 +111,27 @@ func get_raw_input() -> Variant:
 			return _line_edit.text
 
 
-func _set_placeholder(new_placeholder: String) -> void:
-	placeholder = new_placeholder
+func _set_option_data(new_option_data: OptionData) -> void:
+	option_data = new_option_data
 
 	if not is_node_ready():
 		return
 
-	_line_edit.placeholder_text = placeholder
+	# If options are being provided, you can't snap blocks.
+	snap_point.visible = not option_data
 
+	_update_option_input()
 
-func _set_option(value: bool) -> void:
-	option = value
+
+func _set_placeholder(new_placeholder: String) -> void:
+	placeholder = new_placeholder
 
 	if not is_node_ready():
 		return
 
-	# If options are being provided, you can't snap blocks.
-	snap_point.visible = not option
+	_line_edit.placeholder_text = placeholder
+	_input_switcher.tooltip_text = placeholder
+	_option_input.tooltip_text = placeholder
 
 
 func _ready():
@@ -123,7 +139,7 @@ func _ready():
 	stylebox.bg_color = Color.WHITE
 
 	_set_placeholder(placeholder)
-	_set_option(option)
+	_set_option_data(option_data)
 
 	snap_point.block_type = block_type
 	snap_point.variant_type = variant_type
@@ -182,7 +198,7 @@ func _on_y_line_edit_focus_exited():
 func _update_visible_input():
 	if snap_point.has_snapped_block():
 		_switch_input(null)
-	elif option:
+	elif option_data:
 		_switch_input(_option_input)
 	else:
 		match variant_type:
@@ -199,6 +215,44 @@ func _update_visible_input():
 func _switch_input(node: Node):
 	for c in _input_switcher.get_children():
 		c.visible = c == node
+	_panel.visible = node not in [_option_input]
+
+
+func _update_option_input(current_value: Variant = null):
+	if not option_data:
+		return
+
+	if current_value is OptionData:
+		# Temporary hack: previously, the value was stored as an OptionData
+		# object with a list of items and a "selected" property. Instead,
+		# convert that value to the corresponding item.
+		current_value = current_value.items[current_value.selected]
+
+	if current_value == null:
+		current_value = _option_input.get_selected_metadata()
+
+	_option_input.clear()
+
+	var selected_item_index: int = -1
+
+	for item in option_data.items:
+		var item_index = _option_input.item_count
+		var option_label = item.capitalize() if item is String else str(item)
+		_option_input.add_item(option_label)
+		_option_input.set_item_tooltip(item_index, item)
+		_option_input.set_item_metadata(item_index, item)
+		if item == current_value:
+			selected_item_index = item_index
+
+	if _option_input.item_count == 0:
+		var item_index = _option_input.item_count
+		_option_input.add_item("<%s>" % placeholder)
+		_option_input.set_item_disabled(item_index, true)
+		selected_item_index = item_index
+	elif selected_item_index == -1:
+		selected_item_index = option_data.selected
+
+	_option_input.select(selected_item_index)
 
 
 func _on_color_input_color_changed(color):
diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
index bc65c184..7aac4ebb 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
@@ -42,6 +42,7 @@ theme_override_styles/panel = SubResource("StyleBoxFlat_tn6h4")
 [node name="InputSwitcher" type="MarginContainer" parent="."]
 unique_name_in_owner = true
 layout_mode = 2
+tooltip_text = "Parameter"
 mouse_filter = 2
 theme_override_constants/margin_left = 0
 theme_override_constants/margin_top = 0
@@ -84,6 +85,7 @@ unique_name_in_owner = true
 visible = false
 custom_minimum_size = Vector2(40, 0)
 layout_mode = 2
+tooltip_text = "Parameter"
 theme_override_styles/normal = SubResource("StyleBoxEmpty_fjquj")
 
 [node name="Vector2Input" type="MarginContainer" parent="InputSwitcher"]
diff --git a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
index 6b72e0de..32687e9a 100644
--- a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
+++ b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
@@ -113,8 +113,16 @@ func _append_input_parameter(parameter: Dictionary, id: int):
 	parameter_input.name = "ParameterInput%d" % id
 	parameter_input.placeholder = parameter["name"]
 	parameter_input.variant_type = parameter["type"]
-	parameter_input.option = parameter["is_option"]
-	parameter_input.default_value = default_value
+
+	if parameter["is_option"] and default_value is OptionData:
+		var option_data := default_value as OptionData
+		parameter_input.option_data = option_data
+		if option_data.selected < option_data.items.size():
+			parameter_input.default_value = option_data.items[option_data.selected]
+	elif parameter["is_option"]:
+		push_warning("The block parameter %s in %s appears to be an option, but no option data is provided" % [parameter_format, parent_block])
+	else:
+		parameter_input.default_value = default_value
 
 	parameter_input.modified.connect(func(): modified.emit())
 

From 2cfaceac5fcd2c5c81cd271ddf6baae790b43505 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 5 Sep 2024 17:41:40 -0700
Subject: [PATCH 07/13] ParameterInput: Add current value to options list

If the current value is not already in the options list, add it to the
list.

https://phabricator.endlessm.com/T35564
---
 .../utilities/parameter_input/parameter_input.gd    | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
index dec6ebc6..11004dde 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.gd
@@ -244,7 +244,18 @@ func _update_option_input(current_value: Variant = null):
 		if item == current_value:
 			selected_item_index = item_index
 
-	if _option_input.item_count == 0:
+	if selected_item_index == -1 and current_value:
+		# If the current value is not in the default list of options, add it
+		# and select it.
+		if _option_input.item_count > 0:
+			_option_input.add_separator()
+		var item_index = _option_input.item_count
+		var option_label = current_value.capitalize() if current_value is String else str(current_value)
+		_option_input.add_item(option_label)
+		_option_input.set_item_tooltip(item_index, current_value)
+		_option_input.set_item_metadata(item_index, current_value)
+		selected_item_index = item_index
+	elif _option_input.item_count == 0:
 		var item_index = _option_input.item_count
 		_option_input.add_item("<%s>" % placeholder)
 		_option_input.set_item_disabled(item_index, true)

From 41afa00261e17606c0754b8697940f65c79c0194 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 5 Sep 2024 18:08:08 -0700
Subject: [PATCH 08/13] TemplateEditor: Remove the OPTION parameter type

Instead, we infer that a parameter has a set of options by the existence
of an OptionData as its default value.

In addition, add a way for a code template to include a plain, unquoted
string by using `{{parameter}}`. Previously this happened automatically
for any parameter whose value was an OptionData.

https://phabricator.endlessm.com/T35564
---
 .../blocks/graphics/animationplayer_play.tres    | 16 +++++++++++-----
 addons/block_code/blocks/logic/compare.tres      |  4 ++--
 .../blocks/sounds/pause_continue_sound.tres      |  6 +++---
 addons/block_code/code_generation/block_ast.gd   | 14 +++++++++-----
 .../block_code/code_generation/blocks_catalog.gd |  4 ++--
 .../simple_character/simple_character.gd         |  4 ++--
 .../utilities/template_editor/template_editor.gd |  4 +---
 7 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/addons/block_code/blocks/graphics/animationplayer_play.tres b/addons/block_code/blocks/graphics/animationplayer_play.tres
index 7868406a..750111de 100644
--- a/addons/block_code/blocks/graphics/animationplayer_play.tres
+++ b/addons/block_code/blocks/graphics/animationplayer_play.tres
@@ -1,9 +1,14 @@
-[gd_resource type="Resource" load_steps=5 format=3 uid="uid://c5e1byehtxwc0"]
+[gd_resource type="Resource" load_steps=6 format=3 uid="uid://c5e1byehtxwc0"]
 
 [ext_resource type="Script" path="res://addons/block_code/code_generation/block_definition.gd" id="1_emeuv"]
 [ext_resource type="Script" path="res://addons/block_code/code_generation/option_data.gd" id="1_xu43h"]
 [ext_resource type="Script" path="res://addons/block_code/blocks/graphics/animationplayer_play.gd" id="2_7ymgi"]
 
+[sub_resource type="Resource" id="Resource_qpxn2"]
+script = ExtResource("1_xu43h")
+selected = 0
+items = []
+
 [sub_resource type="Resource" id="Resource_vnp2w"]
 script = ExtResource("1_xu43h")
 selected = 0
@@ -17,13 +22,14 @@ description = "Play the animation."
 category = "Graphics | Animation"
 type = 2
 variant_type = 0
-display_template = "Play {animation: OPTION} {direction: OPTION}"
-code_template = "if \"{direction}\" == \"ahead\":
-	play(\"{animation}\")
+display_template = "Play {animation: STRING} {direction: NIL}"
+code_template = "if {direction} == \"ahead\":
+	play({animation})
 else:
-	play_backwards(\"{animation}\")
+	play_backwards({animation})
 "
 defaults = {
+"animation": SubResource("Resource_qpxn2"),
 "direction": SubResource("Resource_vnp2w")
 }
 signal_name = ""
diff --git a/addons/block_code/blocks/logic/compare.tres b/addons/block_code/blocks/logic/compare.tres
index f657ba44..d4b4dc4f 100644
--- a/addons/block_code/blocks/logic/compare.tres
+++ b/addons/block_code/blocks/logic/compare.tres
@@ -16,8 +16,8 @@ description = ""
 category = "Logic | Comparison"
 type = 3
 variant_type = 1
-display_template = "{float1: FLOAT} {op: OPTION} {float2: FLOAT}"
-code_template = "{float1} {op} {float2}"
+display_template = "{float1: FLOAT} {op: NIL} {float2: FLOAT}"
+code_template = "{float1} {{op}} {float2}"
 defaults = {
 "float1": 1.0,
 "float2": 1.0,
diff --git a/addons/block_code/blocks/sounds/pause_continue_sound.tres b/addons/block_code/blocks/sounds/pause_continue_sound.tres
index 3cbfab88..17487bbc 100644
--- a/addons/block_code/blocks/sounds/pause_continue_sound.tres
+++ b/addons/block_code/blocks/sounds/pause_continue_sound.tres
@@ -6,7 +6,7 @@
 [sub_resource type="Resource" id="Resource_lalgp"]
 script = ExtResource("1_ilhdq")
 selected = 0
-items = ["Pause", "Continue"]
+items = ["pause", "continue"]
 
 [resource]
 script = ExtResource("1_q04gm")
@@ -16,9 +16,9 @@ description = "Pause/Continue the audio stream"
 category = "Sounds"
 type = 2
 variant_type = 0
-display_template = "{pause: OPTION} the sound {name: STRING}"
+display_template = "{pause: NIL} the sound {name: STRING}"
 code_template = "var __sound_node = get_node({name})
-if \"{pause}\" == \"pause\":
+if {pause} == \"pause\":
 	__sound_node.stream_paused = true
 else:
 	__sound_node.stream_paused = false
diff --git a/addons/block_code/code_generation/block_ast.gd b/addons/block_code/code_generation/block_ast.gd
index df35e354..2fd3d584 100644
--- a/addons/block_code/code_generation/block_ast.gd
+++ b/addons/block_code/code_generation/block_ast.gd
@@ -55,11 +55,15 @@ class ASTNode:
 			# Use parentheses to be safe
 			var argument = arguments[arg_name]
 			var code_string: String
+			var raw_string: String
 			if argument is ASTValueNode:
 				code_string = argument.get_code()
+				raw_string = code_string
 			else:
 				code_string = BlockAST.raw_input_to_code_string(argument)
+				raw_string = str(argument)
 
+			code_block = code_block.replace("{{%s}}" % arg_name, raw_string)
 			code_block = code_block.replace("{%s}" % arg_name, code_string)
 
 		return IDHandler.make_unique(code_block)
@@ -99,11 +103,15 @@ class ASTValueNode:
 			# Use parentheses to be safe
 			var argument = arguments[arg_name]
 			var code_string: String
+			var raw_string: String
 			if argument is ASTValueNode:
 				code_string = argument.get_code()
+				raw_string = code_string
 			else:
 				code_string = BlockAST.raw_input_to_code_string(argument)
+				raw_string = str(argument)
 
+			code = code.replace("{{%s}}" % arg_name, raw_string)
 			code = code.replace("{%s}" % arg_name, code_string)
 
 		return IDHandler.make_unique("(%s)" % code)
@@ -130,15 +138,11 @@ func to_string_recursive(node: ASTNode, depth: int) -> String:
 static func raw_input_to_code_string(input) -> String:
 	match typeof(input):
 		TYPE_STRING:
-			return "'%s'" % input.replace("\\", "\\\\").replace("'", "\\'")
+			return "'%s'" % input.c_escape()
 		TYPE_VECTOR2:
 			return "Vector2%s" % str(input)
 		TYPE_COLOR:
 			return "Color%s" % str(input)
-		TYPE_OBJECT:
-			if input is OptionData:
-				var option_data := input as OptionData
-				return option_data.items[option_data.selected]
 		_:
 			return "%s" % input
 
diff --git a/addons/block_code/code_generation/blocks_catalog.gd b/addons/block_code/code_generation/blocks_catalog.gd
index 4bc8bb71..8b8f5f5c 100644
--- a/addons/block_code/code_generation/blocks_catalog.gd
+++ b/addons/block_code/code_generation/blocks_catalog.gd
@@ -198,8 +198,8 @@ static func _setup_input_block():
 			"Input",
 			Types.BlockType.VALUE,
 			TYPE_BOOL,
-			"Is action {action_name: OPTION} {action: OPTION}",
-			'Input.is_action_{action}("{action_name}")',
+			"Is action {action_name: STRING_NAME} {action: NIL}",
+			"Input.is_action_{{action}}('{{action_name}}')",
 			{"action_name": OptionData.new(inputmap_actions), "action": OptionData.new(["pressed", "just_pressed", "just_released"])},
 		)
 	)
diff --git a/addons/block_code/simple_nodes/simple_character/simple_character.gd b/addons/block_code/simple_nodes/simple_character/simple_character.gd
index faadfcbe..a5d46d0d 100644
--- a/addons/block_code/simple_nodes/simple_character/simple_character.gd
+++ b/addons/block_code/simple_nodes/simple_character/simple_character.gd
@@ -133,7 +133,7 @@ static func setup_custom_blocks():
 	block_definition.target_node_class = _class_name
 	block_definition.category = "Input"
 	block_definition.type = Types.BlockType.STATEMENT
-	block_definition.display_template = "Move with {player: OPTION} buttons as {kind: OPTION}"
+	block_definition.display_template = "Move with {player: NIL} buttons as {kind: NIL}"
 	block_definition.description = """Move the character using the “Player 1” or “Player 2” controls as configured in Godot.
 
 “Top-down” enables the character to move in both x (vertical) and y (horizontal) dimensions, as if the camera is above the character, looking down. No gravity is added.
@@ -143,7 +143,7 @@ static func setup_custom_blocks():
 “Spaceship” uses the left/right controls to turn the character and up/down controls to go forward or backward."""
 	# TODO: delta here is assumed to be the parameter name of
 	# the _process or _physics_process method:
-	block_definition.code_template = 'move_with_player_buttons("{player}", "{kind}", delta)'
+	block_definition.code_template = "move_with_player_buttons({player}, {kind}, delta)"
 	block_definition.defaults = {
 		"player": OptionData.new(["player_1", "player_2"]),
 		"kind": OptionData.new(["top-down", "platformer", "spaceship"]),
diff --git a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
index 32687e9a..ff8e2ec0 100644
--- a/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
+++ b/addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd
@@ -114,13 +114,11 @@ func _append_input_parameter(parameter: Dictionary, id: int):
 	parameter_input.placeholder = parameter["name"]
 	parameter_input.variant_type = parameter["type"]
 
-	if parameter["is_option"] and default_value is OptionData:
+	if default_value is OptionData:
 		var option_data := default_value as OptionData
 		parameter_input.option_data = option_data
 		if option_data.selected < option_data.items.size():
 			parameter_input.default_value = option_data.items[option_data.selected]
-	elif parameter["is_option"]:
-		push_warning("The block parameter %s in %s appears to be an option, but no option data is provided" % [parameter_format, parent_block])
 	else:
 		parameter_input.default_value = default_value
 

From 414403464d26c94c25c1e98a89d39a81b5cc2cd4 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 12 Sep 2024 14:40:32 -0700
Subject: [PATCH 09/13] ParameterInput: Change option input to fit only the
 selected item

It is possible for some options to be very long, causing a block to
appear wider than necessary.

https://phabricator.endlessm.com/T35564
---
 .../ui/blocks/utilities/parameter_input/parameter_input.tscn     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
index 7aac4ebb..5ed2066e 100644
--- a/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
+++ b/addons/block_code/ui/blocks/utilities/parameter_input/parameter_input.tscn
@@ -87,6 +87,7 @@ custom_minimum_size = Vector2(40, 0)
 layout_mode = 2
 tooltip_text = "Parameter"
 theme_override_styles/normal = SubResource("StyleBoxEmpty_fjquj")
+fit_to_longest_item = false
 
 [node name="Vector2Input" type="MarginContainer" parent="InputSwitcher"]
 unique_name_in_owner = true

From 018836e660ddfd733556902371e79d66d3d471bd Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Wed, 18 Sep 2024 21:41:45 -0700
Subject: [PATCH 10/13] BlocksCatalog: Include base blocks in
 get_inherited_blocks

Instead of getting specific blocks we know to have target_node_class "",
change BlocksCatalog to include those blocks in the return value from
get_inherited_blocks. This is possible due to the newly simplified
implementation of _get_blocks_by_class.

With this change, we can completely remove the list of default block
definition names from BlockScriptSerialization.
---
 .../code_generation/blocks_catalog.gd         | 14 ++---
 .../block_script_serialization.gd             | 59 -------------------
 tests/test_category_factory.gd                | 56 ++++++++++--------
 3 files changed, 37 insertions(+), 92 deletions(-)

diff --git a/addons/block_code/code_generation/blocks_catalog.gd b/addons/block_code/code_generation/blocks_catalog.gd
index 8b8f5f5c..3a1227da 100644
--- a/addons/block_code/code_generation/blocks_catalog.gd
+++ b/addons/block_code/code_generation/blocks_catalog.gd
@@ -224,14 +224,9 @@ static func has_block(block_name: StringName):
 	return block_name in _catalog
 
 
-static func get_blocks_by_class(_class_name: String) -> Array[BlockDefinition]:
+static func _get_blocks_by_class(_class_name: String) -> Array[BlockDefinition]:
 	var result: Array[BlockDefinition]
-
-	if not _class_name:
-		return result
-
 	result.assign(_catalog.values().filter(_block_definition_has_class_name.bind(_class_name)))
-
 	return result
 
 
@@ -263,7 +258,9 @@ static func _get_custom_parent_class_name(_custom_class_name: String) -> String:
 static func _get_parents(_class_name: String) -> Array[String]:
 	if ClassDB.class_exists(_class_name):
 		return _get_builtin_parents(_class_name)
-	var parents: Array[String] = [_class_name]
+	var parents: Array[String] = []
+	if _class_name != "":
+		parents.append(_class_name)
 	var _parent_class_name = _get_custom_parent_class_name(_class_name)
 	parents.append_array(_get_builtin_parents(_parent_class_name))
 	return parents
@@ -274,7 +271,8 @@ static func get_inherited_blocks(_class_name: String) -> Array[BlockDefinition]:
 
 	var definitions: Array[BlockDefinition] = []
 	for _parent_class_name in _get_parents(_class_name):
-		definitions.append_array(get_blocks_by_class(_parent_class_name))
+		definitions.append_array(_get_blocks_by_class(_parent_class_name))
+	definitions.append_array(_get_blocks_by_class(""))
 	return definitions
 
 
diff --git a/addons/block_code/serialization/block_script_serialization.gd b/addons/block_code/serialization/block_script_serialization.gd
index f45844b1..11d83ab1 100644
--- a/addons/block_code/serialization/block_script_serialization.gd
+++ b/addons/block_code/serialization/block_script_serialization.gd
@@ -135,7 +135,6 @@ func _get_parameter_block_definition(block_name: String, parameter_name: String)
 
 func _update_block_definitions():
 	_available_blocks.clear()
-	_available_blocks.append_array(_get_default_block_definitions())
 	_available_blocks.append_array(_get_inherited_block_definitions())
 	_available_blocks.append_array(_get_variable_block_definitions())
 
@@ -176,64 +175,6 @@ func load_object_script() -> Object:
 	return null
 
 
-func _get_default_block_definitions() -> Array[BlockDefinition]:
-	var block: BlockDefinition
-	var block_list: Array[BlockDefinition] = []
-
-	# Lifecycle
-	for block_name in [&"ready", &"process", &"physics_process", &"queue_free"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Loops
-	for block_name in [&"for", &"while", &"break", &"continue", &"await_scene_ready"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Logs
-	block = BlocksCatalog.get_block(&"print")
-	block_list.append(block)
-
-	# Communication
-	for block_name in [&"define_method", &"call_method_group", &"call_method_node"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	for block_name in [&"add_to_group", &"add_node_to_group", &"remove_from_group", &"remove_node_from_group", &"is_in_group", &"is_node_in_group"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Variables
-	block = BlocksCatalog.get_block(&"vector2")
-	block_list.append(block)
-
-	# Math
-	for block_name in [&"add", &"subtract", &"multiply", &"divide", &"pow", &"randf_range", &"randi_range", &"sin", &"cos", &"tan"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Logic
-	for block_name in [&"if", &"else_if", &"else", &"compare", &"and", &"or", &"not"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Input
-	block = BlocksCatalog.get_block(&"is_input_actioned")
-	block_list.append(block)
-
-	# Sounds
-	for block_name in [&"load_sound", &"play_sound", &"pause_continue_sound", &"stop_sound"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	# Graphics
-	for block_name in [&"viewport_width", &"viewport_height", &"viewport_center"]:
-		block = BlocksCatalog.get_block(block_name)
-		block_list.append(block)
-
-	return block_list
-
-
 func _get_inherited_block_definitions() -> Array[BlockDefinition]:
 	return BlocksCatalog.get_inherited_blocks(script_inherits)
 
diff --git a/tests/test_category_factory.gd b/tests/test_category_factory.gd
index 4273b7f6..0b59cb43 100644
--- a/tests/test_category_factory.gd
+++ b/tests/test_category_factory.gd
@@ -8,13 +8,19 @@ const BlocksCatalog = preload("res://addons/block_code/code_generation/blocks_ca
 var block_script: BlockScriptSerialization
 
 
+func assert_set_eq(set_a: Array, set_b: Array, text: String = ""):
+	var set_a_sorted := set_a.duplicate()
+	var set_b_sorted := set_b.duplicate()
+	set_a_sorted.sort()
+	set_b_sorted.sort()
+	assert_eq(set_a_sorted, set_b_sorted, text)
+
+
 func get_category_names(categories: Array[BlockCategory]) -> Array[String]:
-	var categories_sorted: Array[BlockCategory]
-	categories_sorted.assign(categories)
-	categories_sorted.sort_custom(BlockCategory.sort_by_order)
-	var result: Array[String]
-	result.assign(categories_sorted.map(func(category): return category.name))
-	return result
+	var category_names: Array[String]
+	category_names.assign(categories.map(func(category): return category.name))
+	category_names.sort()
+	return category_names
 
 
 func get_class_category_names(_class_name: String) -> Array[String]:
@@ -28,27 +34,27 @@ func before_each():
 	block_script.initialize()
 
 
+const default_category_names = [
+	"Communication | Groups",
+	"Communication | Methods",
+	"Graphics | Viewport",
+	"Input",
+	"Lifecycle",
+	"Log",
+	"Logic | Boolean",
+	"Logic | Comparison",
+	"Logic | Conditionals",
+	"Loops",
+	"Math",
+	"Sounds",
+	"Variables",
+]
+
+
 func test_general_category_names():
 	var blocks: Array[BlockDefinition] = block_script.get_available_blocks()
 	var names: Array[String] = get_category_names(block_script.get_available_categories())
-	assert_eq(
-		names,
-		[
-			"Lifecycle",
-			"Graphics | Viewport",
-			"Sounds",
-			"Input",
-			"Communication | Methods",
-			"Communication | Groups",
-			"Loops",
-			"Logic | Conditionals",
-			"Logic | Comparison",
-			"Logic | Boolean",
-			"Variables",
-			"Math",
-			"Log",
-		]
-	)
+	assert_set_eq(names, default_category_names)
 
 
 const class_category_names = [
@@ -60,7 +66,7 @@ const class_category_names = [
 
 
 func test_inherited_category_names(params = use_parameters(class_category_names)):
-	assert_eq(get_class_category_names(params[0]), params[1])
+	assert_set_eq(get_class_category_names(params[0]), default_category_names + params[1])
 
 
 func test_unique_block_names():

From 33133a61398407a8fa4358c96234a221d6fbfea3 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 19 Sep 2024 10:16:29 -0700
Subject: [PATCH 11/13] BlockAST: Move some duplicated code to a function

---
 .../block_code/code_generation/block_ast.gd   | 66 +++++++------------
 1 file changed, 24 insertions(+), 42 deletions(-)

diff --git a/addons/block_code/code_generation/block_ast.gd b/addons/block_code/code_generation/block_ast.gd
index 2fd3d584..5c2ce1e3 100644
--- a/addons/block_code/code_generation/block_ast.gd
+++ b/addons/block_code/code_generation/block_ast.gd
@@ -44,35 +44,15 @@ class ASTNode:
 		children = []
 		arguments = {}
 
-	func get_code_block() -> String:
-		var code_block: String = data.code_template  # get multiline code_template from block definition
-
-		# insert args
-
-		# check if args match an overload in the resource
-
-		for arg_name in arguments:
-			# Use parentheses to be safe
-			var argument = arguments[arg_name]
-			var code_string: String
-			var raw_string: String
-			if argument is ASTValueNode:
-				code_string = argument.get_code()
-				raw_string = code_string
-			else:
-				code_string = BlockAST.raw_input_to_code_string(argument)
-				raw_string = str(argument)
-
-			code_block = code_block.replace("{{%s}}" % arg_name, raw_string)
-			code_block = code_block.replace("{%s}" % arg_name, code_string)
-
+	func _get_code_block() -> String:
+		var code_block: String = BlockAST.format_code_template(data.code_template, arguments)
 		return IDHandler.make_unique(code_block)
 
 	func get_code(depth: int) -> String:
 		var code: String = ""
 
 		# append code block
-		var code_block := get_code_block()
+		var code_block := _get_code_block()
 		code_block = code_block.indent("\t".repeat(depth))
 
 		code += code_block + "\n"
@@ -95,25 +75,7 @@ class ASTValueNode:
 		arguments = {}
 
 	func get_code() -> String:
-		var code: String = data.code_template  # get code_template from block definition
-
-		# check if args match an overload in the resource
-
-		for arg_name in arguments:
-			# Use parentheses to be safe
-			var argument = arguments[arg_name]
-			var code_string: String
-			var raw_string: String
-			if argument is ASTValueNode:
-				code_string = argument.get_code()
-				raw_string = code_string
-			else:
-				code_string = BlockAST.raw_input_to_code_string(argument)
-				raw_string = str(argument)
-
-			code = code.replace("{{%s}}" % arg_name, raw_string)
-			code = code.replace("{%s}" % arg_name, code_string)
-
+		var code: String = BlockAST.format_code_template(data.code_template, arguments)
 		return IDHandler.make_unique("(%s)" % code)
 
 
@@ -135,6 +97,26 @@ func to_string_recursive(node: ASTNode, depth: int) -> String:
 	return string
 
 
+static func format_code_template(code_template: String, arguments: Dictionary) -> String:
+	for argument_name in arguments:
+		# Use parentheses to be safe
+		var argument_value: Variant = arguments[argument_name]
+		var code_string: String
+		var raw_string: String
+
+		if argument_value is ASTValueNode:
+			code_string = argument_value.get_code()
+			raw_string = code_string
+		else:
+			code_string = BlockAST.raw_input_to_code_string(argument_value)
+			raw_string = str(argument_value)
+
+		code_template = code_template.replace("{{%s}}" % argument_name, raw_string)
+		code_template = code_template.replace("{%s}" % argument_name, code_string)
+
+	return code_template
+
+
 static func raw_input_to_code_string(input) -> String:
 	match typeof(input):
 		TYPE_STRING:

From a14eed59e1b871c05be3e0904ddbaa1953bf3236 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 19 Sep 2024 10:17:16 -0700
Subject: [PATCH 12/13] BlockAST: Convert OptionData to selected value

With a block code script created using a previous version of the plugin,
it is possible for a node's value to still be an OptionData object at
the time BlockAST.format_code_template is called.

https://phabricator.endlessm.com/T35564
---
 addons/block_code/code_generation/block_ast.gd | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/addons/block_code/code_generation/block_ast.gd b/addons/block_code/code_generation/block_ast.gd
index 5c2ce1e3..a90657e2 100644
--- a/addons/block_code/code_generation/block_ast.gd
+++ b/addons/block_code/code_generation/block_ast.gd
@@ -104,6 +104,14 @@ static func format_code_template(code_template: String, arguments: Dictionary) -
 		var code_string: String
 		var raw_string: String
 
+		if argument_value is OptionData:
+			# Temporary hack: previously, the value was stored as an OptionData
+			# object with a list of items and a "selected" property. If we are
+			# using an older block script where that is the case, convert the
+			# value to the value of its selected item.
+			# See also, ParameterInput._update_option_input.
+			argument_value = argument_value.items[argument_value.selected]
+
 		if argument_value is ASTValueNode:
 			code_string = argument_value.get_code()
 			raw_string = code_string

From e8126511fa67992566a0137dde6437e0aa4d6167 Mon Sep 17 00:00:00 2001
From: Dylan McCall <dylan@dylanmccall.ca>
Date: Thu, 19 Sep 2024 11:38:38 -0700
Subject: [PATCH 13/13] Block: Connect template_editor modified signal
 automatically

---
 addons/block_code/ui/blocks/block/block.gd             | 10 ++++++----
 .../ui/blocks/control_block/control_block.tscn         |  1 -
 .../block_code/ui/blocks/entry_block/entry_block.tscn  |  1 -
 .../ui/blocks/parameter_block/parameter_block.tscn     |  1 -
 .../ui/blocks/statement_block/statement_block.tscn     |  1 -
 5 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/addons/block_code/ui/blocks/block/block.gd b/addons/block_code/ui/blocks/block/block.gd
index fcd99cc8..bec48633 100644
--- a/addons/block_code/ui/blocks/block/block.gd
+++ b/addons/block_code/ui/blocks/block/block.gd
@@ -60,6 +60,12 @@ func _update_template_editor():
 
 	template_editor.format_string = definition.display_template if definition else ""
 	template_editor.parameter_defaults = definition.get_defaults_for_node(_context.parent_node) if definition else {}
+	if not template_editor.modified.is_connected(_on_template_editor_modified):
+		template_editor.modified.connect(_on_template_editor_modified)
+
+
+func _on_template_editor_modified():
+	modified.emit()
 
 
 func _gui_input(event):
@@ -84,10 +90,6 @@ func _gui_input(event):
 			EditorInterface.popup_dialog_centered(dialog)
 
 
-func _modified():
-	modified.emit()
-
-
 func remove_from_tree():
 	var parent = get_parent()
 	if parent:
diff --git a/addons/block_code/ui/blocks/control_block/control_block.tscn b/addons/block_code/ui/blocks/control_block/control_block.tscn
index adb481e2..4584c839 100644
--- a/addons/block_code/ui/blocks/control_block/control_block.tscn
+++ b/addons/block_code/ui/blocks/control_block/control_block.tscn
@@ -95,5 +95,4 @@ shift_top = 20.0
 [node name="SnapPoint" parent="VBoxContainer" instance=ExtResource("3_nhryi")]
 layout_mode = 2
 
-[connection signal="modified" from="." to="." method="_modified"]
 [connection signal="mouse_down" from="VBoxContainer/MarginContainer/Rows/Row/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
diff --git a/addons/block_code/ui/blocks/entry_block/entry_block.tscn b/addons/block_code/ui/blocks/entry_block/entry_block.tscn
index fcb8b6a7..a2d0f27e 100644
--- a/addons/block_code/ui/blocks/entry_block/entry_block.tscn
+++ b/addons/block_code/ui/blocks/entry_block/entry_block.tscn
@@ -56,4 +56,3 @@ layout_mode = 2
 layout_mode = 2
 
 [connection signal="mouse_down" from="VBoxContainer/TopMarginContainer/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
-[connection signal="modified" from="VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor" to="." method="_modified"]
diff --git a/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn b/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
index 921f9652..0a01f8f4 100644
--- a/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
+++ b/addons/block_code/ui/blocks/parameter_block/parameter_block.tscn
@@ -48,4 +48,3 @@ theme_override_constants/margin_bottom = 8
 [connection signal="focus_entered" from="." to="." method="_on_focus_entered"]
 [connection signal="focus_exited" from="." to="." method="_on_focus_exited"]
 [connection signal="mouse_down" from="DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
-[connection signal="modified" from="MarginContainer/TemplateEditor" to="." method="_modified"]
diff --git a/addons/block_code/ui/blocks/statement_block/statement_block.tscn b/addons/block_code/ui/blocks/statement_block/statement_block.tscn
index 164f8b21..f2f51a96 100644
--- a/addons/block_code/ui/blocks/statement_block/statement_block.tscn
+++ b/addons/block_code/ui/blocks/statement_block/statement_block.tscn
@@ -55,4 +55,3 @@ layout_mode = 2
 layout_mode = 2
 
 [connection signal="mouse_down" from="VBoxContainer/TopMarginContainer/DragDropArea" to="." method="_on_drag_drop_area_mouse_down"]
-[connection signal="modified" from="VBoxContainer/TopMarginContainer/MarginContainer/TemplateEditor" to="." method="_modified"]