Correct RENDER_PANELS functionality and when enabled disable HistoryPanel.

The render panels setting used to control whether the toolbar would keep
the contents of the panels in the background or render the toolbar on
every page. The history panel relies on loading panels in the background.
If panels should be rendered on the request, then the history panel is
can't/shouldn't work.

Author: tim-schilling

debug_toolbar/panels/history/panel.py

@@ -20,6 +20,12 @@ class HistoryPanel(Panel):
     nav_title = _("History")
     template = "debug_toolbar/panels/history.html"
 
+    @property
+    def enabled(self):
+        # Do not show the history panel if the panels are rendered on request
+        # rather than loaded via ajax.
+        return super().enabled and not self.toolbar.should_render_panels()
+
     @property
     def is_historical(self):
         """The HistoryPanel should not be included in the historical panels."""

debug_toolbar/templates/debug_toolbar/base.html

@@ -7,7 +7,10 @@
 <script type="module" src="{% static 'debug_toolbar/js/toolbar.js' %}" async></script>
 {% endblock %}
 <div id="djDebug" class="djdt-hidden" dir="ltr"
-     {% if toolbar.store_id %}data-store-id="{{ toolbar.store_id }}" data-render-panel-url="{% url 'djdt:render_panel' %}"{% endif %}
+     {% if not toolbar.should_render_panels %}
+     data-store-id="{{ toolbar.store_id }}"
+     data-render-panel-url="{% url 'djdt:render_panel' %}"
+     {% endif %}
      data-default-show="{% if toolbar.config.SHOW_COLLAPSED %}false{% else %}true{% endif %}"
      {{ toolbar.config.ROOT_TAG_EXTRA_ATTRS|safe }}>
   <div class="djdt-hidden" id="djDebugToolbar">

debug_toolbar/templates/debug_toolbar/includes/panel_content.html

@@ -7,11 +7,11 @@
       <h3>{{ panel.title }}</h3>
     </div>
     <div class="djDebugPanelContent">
-      {% if toolbar.store_id %}
+      {% if toolbar.should_render_panels %}
+        <div class="djdt-scroll">{{ panel.content }}</div>
+      {% else %}
         <div class="djdt-loader"></div>
         <div class="djdt-scroll"></div>
-      {% else %}
-        <div class="djdt-scroll">{{ panel.content }}</div>
       {% endif %}
     </div>
   </div>

debug_toolbar/toolbar.py

@@ -78,6 +78,10 @@ def render_toolbar(self):
                 raise
 
     def should_render_panels(self):
+        """Determine whether the panels should be rendered during the request
+
+        If False, the panels will be loaded via Ajax.
+        """
         render_panels = self.config["RENDER_PANELS"]
         if render_panels is None:
             render_panels = self.request.META["wsgi.multiprocess"]

docs/changes.rst

@@ -9,6 +9,10 @@ Next version
 * Added ``PRETTIFY_SQL`` configuration option to support controlling
   SQL token grouping. By default it's set to True. When set to False,
   a performance improvement can be seen by the SQL panel.
+* ``HistoryPanel`` will be disabled when ``RENDER_PANELS`` is ``True``
+  or if it's not set, but the server is running with multiple processes.
+* Fixes ``RENDER_PANELS`` functionality so that when ``True`` panels are
+  rendered during the request and not loaded asynchronously.
 
 
 3.2 (2020-12-03)

docs/configuration.rst

@@ -66,6 +66,8 @@ Toolbar options
   The toolbar searches for this string in the HTML and inserts itself just
   before.
 
+.. _RENDER_PANELS:
+
 * ``RENDER_PANELS``
 
   Default: ``None``

docs/installation.rst

@@ -147,3 +147,11 @@ And for Apache:
 .. _JavaScript module: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
 .. _CORS errors: https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSMissingAllowOrigin
 .. _Access-Control-Allow-Origin header: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
+
+Django Channels & Async
+^^^^^^^^^^^^^^^^^^^^^^^
+
+The Debug Toolbar currently doesn't support Django Channels or async projects.
+If you are using Django channels are having issues getting panels to load,
+please review the documentation for the configuration option
+:ref:`RENDER_PANELS <RENDER_PANELS>`.

docs/panels.rst

@@ -17,6 +17,11 @@ History
 This panel shows the history of requests made and allows switching to a past
 snapshot of the toolbar to view that request's stats.
 
+.. caution::
+   If :ref:`RENDER_PANELS <RENDER_PANELS>` configuration option is set to
+   ``True`` or if the server runs with multiple processes, the History Panel
+   will be disabled.
+
 Version
 ~~~~~~~
 
@@ -184,9 +189,9 @@ URL: https://github.com/danyi1212/django-windowsauth
 
 Path: ``windows_auth.panels.LDAPPanel``
 
-LDAP Operations performed during the request, including timing, request and response messages, 
+LDAP Operations performed during the request, including timing, request and response messages,
 the entries received, write changes list, stack-tracing and error debugging.
-This panel also shows connection usage metrics when it is collected. 
+This panel also shows connection usage metrics when it is collected.
 `Check out the docs <https://django-windowsauth.readthedocs.io/en/latest/howto/debug_toolbar.html>`_.
 
 Line Profiler

tests/test_integration.py

@@ -289,11 +289,44 @@ def test_sql_profile_checks_show_toolbar(self):
             self.assertEqual(response.status_code, 404)
 
     @override_settings(DEBUG_TOOLBAR_CONFIG={"RENDER_PANELS": True})
-    def test_data_store_id_not_rendered_when_none(self):
+    def test_render_panels_in_request(self):
+        """
+        Test that panels are are rendered during the request with
+        RENDER_PANELS=TRUE
+        """
         url = "/regular/basic/"
         response = self.client.get(url)
         self.assertIn(b'id="djDebug"', response.content)
+        # Verify the store id is not included.
         self.assertNotIn(b"data-store-id", response.content)
+        # Verify the history panel was disabled
+        self.assertIn(
+            b'<input type="checkbox" data-cookie="djdtHistoryPanel" '
+            b'title="Enable for next and successive requests">',
+            response.content,
+        )
+        # Verify the a panel was rendered
+        self.assertIn(b"Response headers", response.content)
+
+    @override_settings(DEBUG_TOOLBAR_CONFIG={"RENDER_PANELS": False})
+    def test_load_panels(self):
+        """
+        Test that panels are not rendered during the request with
+        RENDER_PANELS=False
+        """
+        url = "/execute_sql/"
+        response = self.client.get(url)
+        self.assertIn(b'id="djDebug"', response.content)
+        # Verify the store id is included.
+        self.assertIn(b"data-store-id", response.content)
+        # Verify the history panel was not disabled
+        self.assertNotIn(
+            b'<input type="checkbox" data-cookie="djdtHistoryPanel" '
+            b'title="Enable for next and successive requests">',
+            response.content,
+        )
+        # Verify the a panel was not rendered
+        self.assertNotIn(b"Response headers", response.content)
 
     def test_view_returns_template_response(self):
         response = self.client.get("/template_response/basic/")