Extend social meta tags

dash/_pages.py

@@ -380,24 +380,48 @@
     return {}, None
 
 
-def _page_meta_tags(app, request):
-    request_path = request.path
-    start_page, path_variables = _path_to_page(request_path.strip("/"))
+def _get_image_url(app, request, image, supplied_image_url):
+    if supplied_image_url:
+        return supplied_image_url
 
-    image = start_page.get("image", "")
     if image:
+        if image.startswith(("http://", "https://")):
+            return image
+
         image = app.get_asset_url(image)
-    assets_image_url = "".join([request.root, image.lstrip("/")]) if image else None
-    supplied_image_url = start_page.get("image_url")
-    image_url = supplied_image_url if supplied_image_url else assets_image_url
+        return "".join([request.root, image.lstrip("/")])
+
+    return None
 
-    title = start_page.get("title", app.title)
-    if callable(title):
-        title = title(**path_variables) if path_variables else title()
 
-    description = start_page.get("description", "")
-    if callable(description):
-        description = description(**path_variables) if path_variables else description()
+def _page_meta_tags(app, request):
+    if not app.use_pages and not (app.description or app.image):
+        return []
+
+    title = app.title
+    description = app.description or ""
+    image = app.image
+    supplied_image_url = None
+
+    if app.use_pages:
+        request_path = request.path
+        start_page, path_variables = _path_to_page(request_path.strip("/"))
+
+        if start_page:
+            title = start_page.get("title", title)
+            description = start_page.get("description", description)
+            image = start_page.get("image") or image
+            supplied_image_url = start_page.get("image_url")
+
+        if callable(title):
+            title = title(**path_variables) if path_variables else title()
+
+        if callable(description):
+            description = (
+                description(**path_variables) if path_variables else description()
+            )
+
+    image_url = _get_image_url(app, request, image, supplied_image_url)
 
     return [
         {"name": "description", "content": description},

dash/dash.py

@@ -284,9 +284,23 @@ class Dash(ObsoleteChecker):
         to be True. Default `None`.
     :type use_pages: boolean
 
-    :param include_pages_meta: Include the page meta tags for twitter cards.
+    :param include_pages_meta: Include the meta tags for social media cards.
     :type include_pages_meta: bool
 
+    :param title: Default ``Dash``. Configures the document.title
+        (the text that appears in a browser tab).
+
+    :param update_title: Default ``Updating...``. Configures the document.title
+        (the text that appears in a browser tab) text when a callback is being run.
+        Set to None or '' if you don't want the document.title to change or if you
+        want to control the document.title through a separate component or
+        clientside callback.
+
+    :param description:  Sets a default description for meta tags.
+
+    :param image: The default image used for social media cards. Can be the
+        name of an image in the assets folder or an image URL.
+
     :param assets_url_path: The local urls for assets will be:
         ``requests_pathname_prefix + assets_url_path + '/' + asset_path``
         where ``asset_path`` is the path to a file inside ``assets_folder``.
@@ -399,15 +413,6 @@ class Dash(ObsoleteChecker):
         be called after the Flask server is attached.
     :type plugins: list of objects
 
-    :param title: Default ``Dash``. Configures the document.title
-    (the text that appears in a browser tab).
-
-    :param update_title: Default ``Updating...``. Configures the document.title
-    (the text that appears in a browser tab) text when a callback is being run.
-    Set to None or '' if you don't want the document.title to change or if you
-    want to control the document.title through a separate component or
-    clientside callback.
-
     :param background_callback_manager: Background callback manager instance
         to support the ``@callback(..., background=True)`` decorator.
         One of ``DiskcacheManager`` or ``CeleryManager`` currently supported.
@@ -425,8 +430,6 @@ class Dash(ObsoleteChecker):
     `routing_callback_inputs={"language": Input("language", "value")}`
     NOTE: the keys "pathname_" and "search_" are reserved for internal use.
 
-    :param description:  Sets a default description for meta tags on Dash pages (use_pages=True).
-
     :param on_error: Global callback error handler to call when
         an exception is raised. Receives the exception object as first argument.
         The callback_context can be used to access the original callback inputs,
@@ -492,6 +495,10 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
         eager_loading: bool = False,
         include_assets_files: bool = True,
         include_pages_meta: bool = True,
+        title: str = "Dash",
+        update_title: str = "Updating...",
+        description: Optional[str] = None,
+        image: Optional[str] = None,
         url_base_pathname: Optional[str] = None,
         requests_pathname_prefix: Optional[str] = None,
         routes_pathname_prefix: Optional[str] = None,
@@ -506,15 +513,12 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
         show_undo_redo: bool = False,
         extra_hot_reload_paths: Optional[Sequence[str]] = None,
         plugins: Optional[list] = None,
-        title: str = "Dash",
-        update_title: str = "Updating...",
         background_callback_manager: Optional[
             Any
         ] = None,  # Type should be specified if possible
         add_log_handler: bool = True,
         hooks: Optional[RendererHooks] = None,
         routing_callback_inputs: Optional[Dict[str, Union[Input, State]]] = None,
-        description: Optional[str] = None,
         on_error: Optional[Callable[[Exception], Any]] = None,
         use_async: Optional[bool] = None,
         health_endpoint: Optional[str] = None,
@@ -612,6 +616,7 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
             update_title=update_title,
             include_pages_meta=include_pages_meta,
             description=description,
+            image=image,
             health_endpoint=health_endpoint,
             hide_all_callbacks=False,
             csrf_token_name=csrf_token_name,
@@ -645,6 +650,8 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
 
         # keep title as a class property for backwards compatibility
         self.title = title
+        self.description = description
+        self.image = image
 
         # MCP (Model Context Protocol) configuration
         self._enable_mcp = get_combined_config("mcp_enabled", enable_mcp, False)
@@ -1484,7 +1491,8 @@ def index(self, *_args, **_kwargs):
         # Refactored: direct access to global request adapter
         request = self.backend.request_adapter()
 
-        if self.use_pages and self.config.include_pages_meta and request:
+        # include social media meta tags
+        if self.config.include_pages_meta and request:
             metas = _page_meta_tags(self, request) + metas
 
         if self._favicon: