Ensure data models are reused ensuring that notification state persis…

…ts (#7560)

CHANGELOG.md

@@ -14,11 +14,13 @@ This release fixes a regression causing .node_modules to be bundled into our rel
 
 ### Bug fixes
 
+- Ensure Notifications are cleaned up correctly ([#4964](https://github.com/holoviz/panel/pull/4964))
 - Ensure `FileDownload` label text updates correctly ([#7489](https://github.com/holoviz/panel/pull/7489))
 - Fix `Tabulator` aggregation behavior ([#7450](https://github.com/holoviz/panel/pull/7450))
 - Fix typing for `.servable` method ([#7530](https://github.com/holoviz/panel/pull/7530))
 - Ensure `NestedSelect` respects `disabled` parameter ([#7533](https://github.com/holoviz/panel/pull/7533))
 - Ensure errors in hooks aren't masked by fallback to different signature ([#7502](https://github.com/holoviz/panel/pull/7502))
+- Ensure Notifications are only shown once if scheduled onload ([#7504](https://github.com/holoviz/panel/pull/7504))
 
 ### Documentation
 

doc/about/releases.md

@@ -16,11 +16,13 @@ This release fixes a regression causing .node_modules to be bundled into our rel
 
 ### Bug fixes
 
+- Ensure Notifications are cleaned up correctly ([#4964](https://github.com/holoviz/panel/pull/4964))
 - Ensure `FileDownload` label text updates correctly ([#7489](https://github.com/holoviz/panel/pull/7489))
 - Fix `Tabulator` aggregation behavior ([#7450](https://github.com/holoviz/panel/pull/7450))
 - Fix typing for `.servable` method ([#7530](https://github.com/holoviz/panel/pull/7530))
 - Ensure `NestedSelect` respects `disabled` parameter ([#7533](https://github.com/holoviz/panel/pull/7533))
 - Ensure errors in hooks aren't masked by fallback to different signature ([#7502](https://github.com/holoviz/panel/pull/7502))
+- Ensure Notifications are only shown once if scheduled onload ([#7504](https://github.com/holoviz/panel/pull/7504))
 
 ### Documentation
 

panel/io/datamodel.py

@@ -199,7 +199,10 @@ def create_linked_datamodel(obj, root=None):
     else:
         _DATA_MODELS[cls] = model = construct_data_model(obj)
     properties = model.properties()
-    model = model(**{k: v for k, v in obj.param.values().items() if k in properties})
+    props = {k: v for k, v in obj.param.values().items() if k in properties}
+    if root:
+        props['name'] = f"{root.ref['id']}-{id(obj)}"
+    model = model(**props)
     _changing = []
 
     def cb_bokeh(attr, old, new):

panel/io/notifications.py

@@ -34,6 +34,8 @@ class Notification(param.Parameterized):
 
     notification_type = param.String(default=None, constant=True, label='type')
 
+    _rendered = param.Boolean(default=False)
+
     _destroyed = param.Boolean(default=False)
 
     def destroy(self) -> None:
@@ -194,46 +196,45 @@ def __css__(cls):
         })
       """,
       "notifications": """
-        var notification = state.current || data.notifications[data.notifications.length-1]
-        if (notification._destroyed) {
-          return
-        }
-        var config = {
-          duration: notification.duration,
-          type: notification.notification_type,
-          message: notification.message
-        }
-        if (notification.background != null) {
-          config.background = notification.background;
-        }
-        if (notification.icon != null) {
-          config.icon = notification.icon;
-        }
-        var toast = state.toaster.open(config);
-        function destroy() {
-          if (state.current !== notification) {
+        for (notification of data.notifications) {
+          if (notification._destroyed || notification._rendered) {
+            return
+          }
+          var config = {
+            duration: notification.duration,
+            type: notification.notification_type,
+            message: notification.message
+          }
+          if (notification.background != null) {
+            config.background = notification.background;
+          }
+          if (notification.icon != null) {
+            config.icon = notification.icon;
+          }
+          let toast = state.toaster.open(config);
+          function destroy() {
             notification._destroyed = true;
           }
+          notification._rendered = true
+          toast.on('dismiss', destroy)
+          if (notification.duration) {
+            setTimeout(destroy, notification.duration)
+          }
+          if (notification.properties === undefined)
+            return
+          view.connect(notification.properties._destroyed.change, function () {
+            state.toaster.dismiss(toast)
+          })
         }
-        toast.on('dismiss', destroy)
-        if (notification.duration) {
-          setTimeout(destroy, notification.duration)
-        }
-        if (notification.properties === undefined)
-          return
-        view.connect(notification.properties._destroyed.change, function () {
-          state.toaster.dismiss(toast)
-        })
       """,
       "_clear": "state.toaster.dismissAll()",
       "position": """
         script('_clear');
         script('render');
         for (notification of data.notifications) {
-          state.current = notification;
-          script('notifications');
+          notification._rendered = false;
         }
-        state.current = undefined
+        script('notifications');
       """
     }
 

panel/reactive.py

@@ -2170,6 +2170,27 @@ def _update_model(
                 )
             ):
                 continue
+            elif isinstance(v, list) and all(isinstance(vs, param.Parameterized) for vs in v):
+                from .io.datamodel import create_linked_datamodel
+                old = getattr(model.data, prop)
+                if isinstance(old, list):
+                    mapping = {o.name: o for o in old}
+                    vals = []
+                    for vs in v:
+                        if (vname:=f"{root.ref['id']}-{id(vs)}") in mapping:
+                            vals.append(mapping[vname])
+                        else:
+                            vals.append(create_linked_datamodel(vs, root))
+                    v = vals
+                data_msg[prop] = v
+            elif isinstance(v, param.Parameterized):
+                from .io.datamodel import create_linked_datamodel
+                old = getattr(model.data, prop)
+                if old.name == f"{root.ref['id']}-{id(v)}":
+                    v = old
+                else:
+                    v = create_linked_datamodel(vs, root)
+                data_msg[prop] = v
             elif isinstance(v, str):
                 data_msg[prop] = HTML_SANITIZER.clean(v)
             else:

panel/tests/ui/io/test_notifications.py

@@ -70,4 +70,19 @@ def app():
 
     page.click('.bk-btn')
 
-    expect(page.locator('.notyf__message')).to_have_text('Disconnected!')
+
+def test_onload_notification(page):
+    def onload_callback():
+        state.notifications.warning("Warning", duration=0)
+        state.notifications.info("Info", duration=0)
+
+    def app():
+        config.notifications = True
+        state.onload(onload_callback)
+        return Markdown("# Hello world")
+
+    serve_component(page, app)
+
+    expect(page.locator('.notyf__message')).to_have_count(2)
+    expect(page.locator('.notyf__message').nth(0)).to_have_text("Warning")
+    expect(page.locator('.notyf__message').nth(1)).to_have_text("Info")