Add loading_indicator to global config

doc/api/config.md

@@ -22,6 +22,9 @@ The `pn.config` object allows setting various configuration variables, the confi
 `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.
 
+`loading_indicator`
+: Whether a loading indicator is shown by default when panes are updating.
+
 `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

@@ -772,15 +772,22 @@ class ParamMethod(ReplacementPane):
         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=None, 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
+            'defer_load' not in params and
+            self.param.defer_load.default is None
+
         ):
             params['defer_load'] = config.defer_load
+        if (
+            'loading_indicator' not in params and
+            self.param.loading_indicator.default is None
+        ):
+            params['loading_indicator'] = config.loading_indicator           
         super().__init__(object, **params)
         self._evaled = not (self.lazy or self.defer_load)
         self._link_object_params()

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_defer_load():
+    # When
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==False
+
+    # When
+    config.defer_load=False
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==False
+
+    # When
+    config.defer_load=True
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.defer_load==True
+
+    # Clean Up
+    config.defer_load=config.param.defer_load.default
+
+def test_param_function_pane_loading_indicator():
+    # When
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==False
+
+    # When
+    config.loading_indicator=False
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==False
+
+    # When
+    config.loading_indicator=True
+    app = ParameterizedMock()
+    test = ParamMethod(app.click_view)
+    # Then
+    assert test.loading_indicator==True
+
+    # Clean Up
+    config.loading_indicator=config.param.loading_indicator.default
 
 def test_param_function_pane_update(document, comm):
     test = View()