Merge branch 'plotly:dev' into insistence-dev

Author: insistence

CHANGELOG.md

@@ -6,8 +6,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## Added
 
+- [#2826](https://github.com/plotly/dash/pull/2826) When using Pages, allows for `app.title` and (new) `app.description` to be used as defaults for the page title and description. Fixes [#2811](https://github.com/plotly/dash/issues/2811).
 - [#2795](https://github.com/plotly/dash/pull/2795) Allow list of components to be passed as layout.
-- [2760](https://github.com/plotly/dash/pull/2760) New additions to dcc.Loading resolving multiple issues:
+- [#2760](https://github.com/plotly/dash/pull/2760) New additions to dcc.Loading resolving multiple issues:
   - `delay_show` and `delay_hide` props  to prevent flickering during brief loading periods (similar to Dash Bootstrap Components dbc.Spinner)
   - `overlay_style` for styling the loading overlay,  such as setting  visibility and opacity for children
   - `target_components` specifies components/props triggering the loading spinner

dash/_pages.py

@@ -235,13 +235,14 @@ def register_page(
        order `0`
 
     - `title`:
-       (string or function) The name of the page <title>. That is, what appears in the browser title.
-       If not supplied, will use the supplied `name` or will be inferred by module,
-       e.g. `pages.weekly_analytics` to `Weekly analytics`
+       (string or function) Specifies the page title displayed in the browser tab.
+        If not supplied, the app's title is used if different from the default "Dash".
+        Otherwise, the title is the given `name` or inferred from the module name.
+        For example, `pages.weekly_analytics` is inferred as "Weekly Analytics".
 
     - `description`:
        (string or function) The <meta type="description"></meta>.
-       If not supplied, then nothing is supplied.
+       If not defined, the application description will be used if available.
 
     - `image`:
        The meta description image used by social media platforms.
@@ -319,10 +320,18 @@ def register_page(
     )
     page.update(
         supplied_title=title,
-        title=(title if title is not None else page["name"]),
+        title=title
+        if title is not None
+        else CONFIG.title
+        if CONFIG.title != "Dash"
+        else page["name"],
     )
     page.update(
-        description=description if description else "",
+        description=description
+        if description
+        else CONFIG.description
+        if CONFIG.description
+        else "",
         order=order,
         supplied_order=order,
         supplied_layout=layout,

dash/dash.py

@@ -366,6 +366,9 @@ class Dash:
     functions. The syntax for this parameter is a dict of State objects:
     `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).
+
     """
 
     _plotlyjs_url: str
@@ -404,6 +407,7 @@ def __init__(  # pylint: disable=too-many-statements
         add_log_handler=True,
         hooks: Union[RendererHooks, None] = None,
         routing_callback_inputs: Optional[Dict[str, Union[Input, State]]] = None,
+        description=None,
         **obsolete,
     ):
         _validate.check_obsolete(obsolete)
@@ -458,6 +462,7 @@ def __init__(  # pylint: disable=too-many-statements
             title=title,
             update_title=update_title,
             include_pages_meta=include_pages_meta,
+            description=description,
         )
         self.config.set_read_only(
             [

tests/integration/multi_page/test_pages_layout.py

@@ -235,3 +235,27 @@ def test_pala005_routing_inputs(dash_duo, clear_pages_state):
     # Changing the language Input re-runs the layout function
     dash_duo.select_dcc_dropdown("#language", "fr")
     dash_duo.wait_for_text_to_equal("#contents", "Le hash dit: #123")
+
+
+def get_app_title_description():
+    app = Dash(
+        __name__, use_pages=True, title="App Title", description="App Description"
+    )
+    dash.register_page("home", layout=html.Div("Home"), path="/")
+    dash.register_page(
+        "page1",
+        layout=html.Div("Page1"),
+        title="Page 1 Title",
+        description="Page 1 Description",
+    )
+    app.layout = html.Div(dash.page_container)
+    return app
+
+
+def test_pala006_app_title_discription(dash_duo, clear_pages_state):
+    dash_duo.start_server(get_app_title_description())
+
+    assert dash.page_registry["home"]["title"] == "App Title"
+    assert dash.page_registry["page1"]["title"] == "Page 1 Title"
+    assert dash.page_registry["home"]["description"] == "App Description"
+    assert dash.page_registry["page1"]["description"] == "Page 1 Description"