Adding heuristic function for observing requests

Also adding generate_headers function

Author: gone

debug_toolbar/middleware.py

@@ -21,6 +21,13 @@ def show_toolbar(request):
     return settings.DEBUG and request.META.get("REMOTE_ADDR") in settings.INTERNAL_IPS
 
 
+def observe_request(request):
+    """
+    Default function to determine whether to update the toolbar from a client side request
+    """
+    return not DebugToolbar.is_toolbar_request(request)
+
+
 @lru_cache()
 def get_show_toolbar():
     # If SHOW_TOOLBAR_CALLBACK is a string, which is the recommended
@@ -32,6 +39,17 @@ def get_show_toolbar():
         return func_or_path
 
 
+@lru_cache()
+def get_observe_request():
+    # If OBSERVE_REQUEST_CALLBACK is a string, which is the recommended
+    # setup, resolve it to the corresponding callable.
+    func_or_path = dt_settings.get_config()["OBSERVE_REQUEST_CALLBACK"]
+    if isinstance(func_or_path, str):
+        return import_string(func_or_path)
+    else:
+        return func_or_path
+
+
 class DebugToolbarMiddleware:
     """
     Middleware to set up Debug Toolbar on incoming request and render toolbar
@@ -67,12 +85,12 @@ def __call__(self, request):
             panel.generate_stats(request, response)
             panel.generate_server_timing(request, response)
 
-        response = self.generate_server_timing_header(response, toolbar.enabled_panels)
-
         # Always render the toolbar for the history panel, even if it is not
         # included in the response.
         rendered = toolbar.render_toolbar()
 
+        response = self.generate_headers(request, response, toolbar.enabled_panels)
+
         # Check for responses where the toolbar can't be inserted.
         content_encoding = response.get("Content-Encoding", "")
         content_type = response.get("Content-Type", "").split(";")[0]
@@ -96,22 +114,24 @@ def __call__(self, request):
         return response
 
     @staticmethod
-    def generate_server_timing_header(response, panels):
-        data = []
+    def generate_headers(request, response, panels):
+        stats_data = []
 
         for panel in panels:
+            response = panel.generate_headers(request, response)
             stats = panel.get_server_timing_stats()
             if not stats:
                 continue
 
             for key, record in stats.items():
                 # example: `SQLPanel_sql_time;dur=0;desc="SQL 0 queries"`
-                data.append(
+                stats_data.append(
                     '{}_{};dur={};desc="{}"'.format(
                         panel.panel_id, key, record.get("value"), record.get("title")
                     )
                 )
 
-        if data:
-            response["Server-Timing"] = ", ".join(data)
+        if stats_data:
+            response["Server-Timing"] = ", ".join(stats_data)
+
         return response

debug_toolbar/panels/__init__.py

@@ -192,6 +192,15 @@ def process_request(self, request):
         """
         return self.get_response(request)
 
+    def generate_headers(self, request, response):
+        """
+        Attach headers to response.
+
+        Call after procssing the request, gives the panel an opportunity to
+        add headers to the outgoing response
+        """
+        return response
+
     def generate_stats(self, request, response):
         """
         Called after :meth:`process_request

debug_toolbar/panels/history/panel.py

@@ -8,6 +8,7 @@
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 
+from debug_toolbar.middleware import get_observe_request
 from debug_toolbar.panels import Panel
 from debug_toolbar.panels.history import views
 from debug_toolbar.panels.history.forms import HistoryStoreForm
@@ -20,11 +21,10 @@ class HistoryPanel(Panel):
     nav_title = _("History")
     template = "debug_toolbar/panels/history.html"
 
-    def process_request(self, request):
-        response = super().process_request(request)
-        if not self.toolbar.should_render_panels():
-            self.toolbar.store()
-            store_id = self.toolbar.store_id
+    def generate_headers(self, request, response):
+        observe_request = get_observe_request()
+        store_id = getattr(self.toolbar, "store_id")
+        if store_id and observe_request(request):
             sig = SignedDataForm(
                 initial=HistoryStoreForm(initial={"store_id": store_id}).initial
             ).initial.get("signed")

debug_toolbar/settings.py

@@ -37,7 +37,7 @@
     "SHOW_TEMPLATE_CONTEXT": True,
     "SKIP_TEMPLATE_PREFIXES": ("django/forms/widgets/", "admin/widgets/"),
     "SQL_WARNING_THRESHOLD": 500,  # milliseconds
-    "UPDATE_ON_AJAX": False,
+    "OBSERVE_REQUEST_CALLBACK": "debug_toolbar.middleware.observe_request",
 }
 
 

debug_toolbar/templates/debug_toolbar/base.html

@@ -11,8 +11,9 @@
      data-store-id="{{ toolbar.store_id }}"
      data-render-panel-url="{% url 'djdt:render_panel' %}"
      {% endif %}
-     {% if toolbar.should_update_on_ajax %}
-     data-sidebar-url="{% url 'djdt:history_sidebar' %}"
+     {% url 'djdt:history_sidebar' as history_url %}
+     {% if history_url %}
+     data-sidebar-url="{{ history_url }}"
      {% endif %}
      data-default-show="{% if toolbar.config.SHOW_COLLAPSED %}false{% else %}true{% endif %}"
      {{ toolbar.config.ROOT_TAG_EXTRA_ATTRS|safe }}>

debug_toolbar/toolbar.py

@@ -9,8 +9,8 @@
 from django.core.exceptions import ImproperlyConfigured
 from django.template import TemplateSyntaxError
 from django.template.loader import render_to_string
-from django.urls import path, resolve, reverse
-from django.urls.exceptions import NoReverseMatch, Resolver404
+from django.urls import path, resolve
+from django.urls.exceptions import Resolver404
 from django.utils.module_loading import import_string
 
 from debug_toolbar import settings as dt_settings
@@ -88,17 +88,6 @@ def should_render_panels(self):
             render_panels = self.request.META["wsgi.multiprocess"]
         return render_panels
 
-    def should_update_on_ajax(self):
-        """Determine whether the toolbar should consider ajax requests as updates or not"""
-        has_endpoint_registered = False
-        try:
-            reverse("djdt:history_sidebar")
-            has_endpoint_registered = True
-        except NoReverseMatch:
-            pass
-        should_watch = self.config["UPDATE_ON_AJAX"]
-        return should_watch and has_endpoint_registered
-
     # Handle storing toolbars in memory and fetching them later on
 
     _store = OrderedDict()