Make SHOW_TOOLBAR_CALLBACK a dotted path.

Fix #473.

3 files changed, 20 insertions, 16 deletions

diff --git a/debug_toolbar/middleware.py b/debug_toolbar/middleware.py
index e402553..b7114af 100644
--- a/debug_toolbar/middleware.py
+++ b/debug_toolbar/middleware.py
@@ -37,12 +37,8 @@ class DebugToolbarMiddleware(object):
     """
     debug_toolbars = {}
 
-    def __init__(self):
-        self.show_toolbar = dt_settings.CONFIG['SHOW_TOOLBAR_CALLBACK'] or show_toolbar
-        self.insert_before = dt_settings.CONFIG['INSERT_BEFORE']
-
     def process_request(self, request):
-        if not self.show_toolbar(request):
+        if not dt_settings.CONFIG['SHOW_TOOLBAR_CALLBACK'](request):
             return
         response = None
         toolbar = DebugToolbar(request)
@@ -82,7 +78,7 @@ class DebugToolbarMiddleware(object):
                 response.get('Content-Type', '').split(';')[0] in _HTML_TYPES):
             content = force_text(response.content, encoding=settings.DEFAULT_CHARSET)
             try:
-                insert_at = content.lower().rindex(self.insert_before.lower())
+                insert_at = content.lower().rindex(dt_settings.CONFIG['INSERT_BEFORE'].lower())
             except ValueError:
                 pass
             else:
diff --git a/debug_toolbar/settings.py b/debug_toolbar/settings.py
index 5a58b6b..8534c2a 100644
--- a/debug_toolbar/settings.py
+++ b/debug_toolbar/settings.py
@@ -20,7 +20,7 @@ CONFIG_DEFAULTS = {
     'RESULTS_STORE_SIZE': 10,
     'ROOT_TAG_EXTRA_ATTRS': '',
     'SHOW_COLLAPSED': False,
-    'SHOW_TOOLBAR_CALLBACK': None,
+    'SHOW_TOOLBAR_CALLBACK': 'debug_toolbar.middleware.show_toolbar',
     # Panel options
     'EXTRA_SIGNALS': [],
     'ENABLE_STACKTRACES': True,
@@ -36,7 +36,6 @@ CONFIG_DEFAULTS = {
     'SQL_WARNING_THRESHOLD': 500,   # milliseconds
 }
 
-CONFIG = CONFIG_DEFAULTS.copy()
 USER_CONFIG = getattr(settings, 'DEBUG_TOOLBAR_CONFIG', {})
 # Backward-compatibility for 1.0, remove in 2.0.
 _RENAMED_CONFIG = {
@@ -60,7 +59,18 @@ if 'TAG' in USER_CONFIG:
         "TAG was replaced by INSERT_BEFORE. Update your "
         "DEBUG_TOOLBAR_CONFIG setting.", DeprecationWarning)
     USER_CONFIG['INSERT_BEFORE'] = '</%s>' % USER_CONFIG.pop('TAG')
+
+CONFIG = CONFIG_DEFAULTS.copy()
 CONFIG.update(USER_CONFIG)
+if isinstance(CONFIG['SHOW_TOOLBAR_CALLBACK'], six.string_types):
+    # Replace this with import_by_path in Django >= 1.6.
+    mod_path, func_name = CONFIG['SHOW_TOOLBAR_CALLBACK'].rsplit('.', 1)
+    mod = import_module(mod_path)
+    CONFIG['SHOW_TOOLBAR_CALLBACK'] = getattr(mod, func_name)
+else:
+    warnings.warn(
+        "SHOW_TOOLBAR_CALLBACK is now a dotted path. Update your "
+        "DEBUG_TOOLBAR_CONFIG setting.", DeprecationWarning)
 
 
 PANELS_DEFAULTS = [
diff --git a/docs/configuration.rst b/docs/configuration.rst
index a276aa3..c1fe65d 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -85,15 +85,13 @@ Toolbar options
 
 * ``SHOW_TOOLBAR_CALLBACK``
 
-  Default: ``None``
+  Default: 'debug_toolbar.middleware.show_toolbar'
 
-  If set to ``None``, the debug toolbar middleware will use its built-in
-  ``show_toolbar`` method for determining whether the toolbar should show or
-  not. The default checks are that ``DEBUG`` must be set to ``True``, the IP
-  of the request must be in ``INTERNAL_IPS``, and the request must no be an
-  AJAX request. You can provide your own method for displaying the toolbar
-  which contains your custom logic. This method should return ``True`` or
-  ``False``.
+  This is the dotted path to a function used for determining whether the
+  toolbar should show or not. The default checks are that ``DEBUG`` must be
+  set to ``True``, the IP of the request must be in ``INTERNAL_IPS``, and the
+  request must no be an AJAX request. You can provide your own function that
+  accepts a request in argument and returns ``True`` or ``False``.
 
 Panel options
 ~~~~~~~~~~~~~