optionally skip remote extensions (#16)

* optionally skip validation of remotely referenced extensions

* update cli

stac_pydantic/item.py

@@ -75,13 +75,15 @@ def to_json(self, **kwargs):
 
 @lru_cache
 def _extension_model_factory(
-    stac_extensions: Tuple[str], base_class: Type[Item]
+    stac_extensions: Tuple[str], base_class: Type[Item], skip_remote_refs: bool = False
 ) -> Tuple[Type[BaseModel], FieldInfo]:
     """
     Create a stac item properties model for a set of stac extensions
     """
     fields = decompose_model(base_class.__fields__["properties"].type_)
     for ext in stac_extensions:
+        if skip_remote_refs and ext.startswith("http"):
+            continue
         if ext == "checksum":
             continue
         fields.update(decompose_model(Extensions.get(ext)))
@@ -91,7 +93,9 @@ def _extension_model_factory(
     )
 
 
-def item_model_factory(item: Dict, base_class: Type[Item] = Item) -> Type[BaseModel]:
+def item_model_factory(
+    item: Dict, skip_remote_refs: bool = False, base_class: Type[Item] = Item
+) -> Type[BaseModel]:
     """
     Create a pydantic model based on the extensions used by the item
     """
@@ -100,7 +104,7 @@ def item_model_factory(item: Dict, base_class: Type[Item] = Item) -> Type[BaseMo
 
     if stac_extensions:
         item_fields["properties"] = _extension_model_factory(
-            tuple(stac_extensions), base_class
+            tuple(stac_extensions), base_class, skip_remote_refs
         )
 
     return create_model("CustomStacItem", **item_fields, __base__=base_class)

stac_pydantic/scripts/cli.py

@@ -19,7 +19,7 @@ def validate_item(infile):
     r.raise_for_status()
     stac_item = r.json()
     try:
-        item_model_factory(stac_item)(**stac_item)
+        item_model_factory(stac_item, skip_remote_refs=True)(**stac_item)
     except ValidationError as e:
         click.echo(str(e))
         return

tests/test_models.py

@@ -614,3 +614,15 @@ class TestExtension(BaseModel):
 def test_get_missing_extension():
     with pytest.raises(AttributeError):
         Extensions.get("not-an-extension")
+
+
+def test_skip_remote_extension():
+    test_item = request(EO_EXTENSION)
+    test_item["stac_extensions"].append("http://some-remote-extension.json.schema")
+
+    # This should fail
+    with pytest.raises(AttributeError):
+        item_model_factory(test_item, skip_remote_refs=False)(**test_item)
+
+    # This should work
+    item_model_factory(test_item, skip_remote_refs=True)(**test_item)