Extensible CustomPage class (#962)

frontend/taipy-gui/base/src/app.ts

@@ -141,6 +141,10 @@ export class TaipyApp {
     upload(encodedName: string, files: FileList, progressCallback: (val: number) => void) {
         return uploadFile(encodedName, files, progressCallback, this.clientId);
     }
+
+    getPageMetadata() {
+        return JSON.parse(localStorage.getItem("tp_cp_meta") || "{}");
+    }
 }
 
 export const createApp = (onInit?: OnInitHandler, onChange?: OnChangeHandler, path?: string, socket?: Socket) => {

frontend/taipy-gui/base/src/index.ts

@@ -7,4 +7,5 @@ export type { OnChangeHandler, OnInitHandler, ModuleData };
 
 window.addEventListener("beforeunload", () => {
     document.cookie = "tprh=;path=/;Max-Age=-99999999;";
+    localStorage.removeItem("tp_cp_meta");
 });

frontend/taipy-gui/src/components/Taipy/Navigate.tsx

@@ -34,9 +34,14 @@ const Navigate = ({ to, params, tab, force }: NavigateProps) => {
             const searchParams = new URLSearchParams(params || "");
             // Handle Resource Handler Id
             let tprh: string | null = null;
+            let meta: string | null = null;
             if (searchParams.has("tprh")) {
                 tprh = searchParams.get("tprh");
                 searchParams.delete("tprh");
+                if (searchParams.has("tp_cp_meta")) {
+                    meta = searchParams.get("tp_cp_meta");
+                    searchParams.delete("tp_cp_meta");
+                }
             }
             if (Object.keys(state.locations || {}).some((route) => tos === route)) {
                 const searchParamsLocation = new URLSearchParams(location.search);
@@ -47,6 +52,9 @@ const Navigate = ({ to, params, tab, force }: NavigateProps) => {
                     if (tprh !== null) {
                         // Add a session cookie for the resource handler id
                         document.cookie = `tprh=${tprh};path=/;`;
+                        if (meta !== null) {
+                            localStorage.setItem("tp_cp_meta", meta);
+                        }
                         navigate(0);
                     }
                 }

taipy/gui/custom/_page.py

@@ -23,13 +23,20 @@ class Page(BasePage):
     A custom page for external application that can be added to Taipy GUI"""
 
     def __init__(
-        self, resource_handler: ResourceHandler, binding_variables: t.Optional[t.List[str]] = None, **kwargs
+        self,
+        resource_handler: ResourceHandler,
+        binding_variables: t.Optional[t.List[str]] = None,
+        metadata: t.Optional[t.Dict[str, t.Any]] = None,
+        **kwargs,
     ) -> None:
         if binding_variables is None:
             binding_variables = []
+        if metadata is None:
+            metadata = {}
         super().__init__(**kwargs)
         self._resource_handler = resource_handler
         self._binding_variables = binding_variables
+        self._metadata: t.Dict[str, t.Any] = metadata
 
 
 class ResourceHandler(ABC):

taipy/gui/gui.py

@@ -2114,6 +2114,7 @@ class Gui:
                 to=page_name,
                 params={
                     _Server._RESOURCE_HANDLER_ARG: pr._resource_handler.get_id(),
+                    _Server._CUSTOM_PAGE_META_ARG: json.dumps(pr._metadata, cls=_TaipyJsonEncoder)
                 },
             ):
                 # Proactively handle the bindings of custom page variables

taipy/gui/page.py

@@ -46,6 +46,9 @@ class Page:
             self._frame = self._renderer._frame
         elif isinstance(self, CustomPage):
             self._frame = t.cast(FrameType, t.cast(FrameType, inspect.stack()[2].frame))
+            # Allow CustomPage class to be inherited
+            if len(inspect.stack()) > 3 and inspect.stack()[2].function != "<module>":
+                self._frame = t.cast(FrameType, t.cast(FrameType, inspect.stack()[3].frame))
         elif len(inspect.stack()) < 4:
             raise RuntimeError(f"Can't resolve module. Page '{type(self).__name__}' is not registered.")
         else:

taipy/gui/server.py

@@ -48,6 +48,7 @@ class _Server:
     __OPENING_CURLY = r"\1{"
     __CLOSING_CURLY = r"}\2"
     _RESOURCE_HANDLER_ARG = "tprh"
+    _CUSTOM_PAGE_META_ARG = "tp_cp_meta"
 
     def __init__(
         self,