Add loading_indicator to global config (#4259)

doc/user_guide/Overview.md

@@ -147,24 +147,25 @@ The `pn.config` object allows setting various configuration variables, the confi
 `css_files`
 : External CSS files to load.
 
-`js_files`
-: External JS files to load. Dictionary should map from exported name to the URL of the JS file.
-
-`loading_spinner`
-: The style of the global loading indicator, e.g. 'arcs', 'bars', 'dots', 'petals'.
-
-`loading_color`
-: The color of the global loading indicator as a hex color, e.g. #6a6a6a
-
 `defer_load`
 : Whether reactive function evaluation is deferred until the page is rendered.
 
 `exception_handler`
 : A custom exception handler can be defined which should accept any exceptions raised while processing events originating from the frontend and onload callbacks.
+ng.
+
+`js_files`
+: External JS files to load. Dictionary should map from exported name to the URL of the JS file.
+
+`loading_color`
+: The color of the global loading indicator as a hex color, e.g. #6a6a6a
 
 `loading_indicator`
 : Whether a loading indicator is shown by default when panes are updating.
 
+`loading_spinner`
+: The style of the global loading indicator, e.g. 'arcs', 'bars', 'dots', 'petals'.
+
 `nthreads`
 : If set will start a `ThreadPoolExecutor` to dispatch events to for concurrent execution on separate cores. By default no thread pool is launched, while setting nthreads=0 launches `min(32, os.cpu_count() + 4)` threads.
 

panel/config.py

@@ -121,6 +121,9 @@ class _config(_base_config):
     load_entry_points = param.Boolean(default=True, doc="""
         Load entry points from external packages.""")
 
+    loading_indicator = param.Boolean(default=False, doc="""
+        Whether a loading indicator is shown by default while panes are updating.""")
+
     loading_spinner = param.Selector(default='arc', objects=[
         'arc', 'arcs', 'bar', 'dots', 'petal'], doc="""
         Loading indicator to use when component loading parameter is set.""")

panel/param.py

@@ -764,23 +764,19 @@ class ParamMethod(ReplacementPane):
     return any object which itself can be rendered as a Pane.
     """
 
-    defer_load = param.Boolean(default=None, doc="""
+    defer_load = param.Boolean(default=config.defer_load, doc="""
         Whether to defer load until after the page is rendered.
         Can be set as parameter or by setting panel.config.defer_load.""")
 
     lazy = param.Boolean(default=False, doc="""
         Whether to lazily evaluate the contents of the object
         only when it is required for rendering.""")
 
-    loading_indicator = param.Boolean(default=False, doc="""
-        Whether to show loading indicator while pane is updating.""")
+    loading_indicator = param.Boolean(default=config.loading_indicator, doc="""
+        Whether to show a loading indicator while the pane is updating.
+        Can be set as parameter or by setting panel.config.loading_indicator.""")
 
     def __init__(self, object=None, **params):
-        if (
-            self.param.defer_load.default is None and
-            'defer_load' not in params and config.defer_load
-        ):
-            params['defer_load'] = config.defer_load
         super().__init__(object, **params)
         self._evaled = not (self.lazy or self.defer_load)
         self._link_object_params()
@@ -920,7 +916,13 @@ def _get_model(
     def applies(cls, obj: Any) -> float | bool | None:
         return inspect.ismethod(obj) and isinstance(get_method_owner(obj), param.Parameterized)
 
+@param.depends(config.param.defer_load, watch=True)
+def _update_defer_load_default(default_value):
+    ParamMethod.param.defer_load.default = default_value
 
+@param.depends(config.param.loading_indicator, watch=True)
+def _update_loading_indicator_default(default_value):
+    ParamMethod.param.loading_indicator.default = default_value
 
 class ParamFunction(ParamMethod):
     """

panel/tests/test_param.py

@@ -10,6 +10,7 @@
     TextInput as BkTextInput, Toggle,
 )
 
+from panel import config
 from panel.io.state import set_curdoc, state
 from panel.layout import Row, Tabs
 from panel.pane import (
@@ -1095,6 +1096,60 @@ def view(a):
     assert pane._models == {}
     assert inner_pane._models == {}
 
+class ParameterizedMock(param.Parameterized):
+        run = param.Event()
+
+        @param.depends("run")
+        def click_view(self):
+            return "click..."
+
+def test_param_function_pane_config_defer_load():
+    # When
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==config.defer_load
+
+    # When
+    config.defer_load=not config.defer_load
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==config.defer_load
+
+    # When
+    config.defer_load=not config.defer_load
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==config.defer_load
+
+    # Clean Up
+    config.defer_load=config.param.defer_load.default
+
+def test_param_function_pane_config_loading_indicator():
+    # When
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==config.loading_indicator
+
+    # When
+    config.loading_indicator=not config.loading_indicator
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==config.loading_indicator
+
+    # When
+    config.loading_indicator=not config.loading_indicator
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==config.loading_indicator
+
+    # Clean Up
+    config.loading_indicator=config.param.loading_indicator.default
 
 def test_param_function_pane_update(document, comm):
     test = View()