Added conditional tracking consent for Matomo

Modified utils.build_paq_cmd to remove the trailing comma and white space as well as add a semi colon to the end of the push command.
Added context_providers directory with matomo.py file with a context provider that builds the tracking consent code and adds it to the context.
Modified matomo.MatomoNode.render. Removed original ugly settings check code with simply rendering the 'consent_script' context variable and adding it to the html variable only if its length is greater than 1.
NOTE: The context provider and rendering it (line 110 templatetags/matomo.py) are untested. Both utils.build_paq_cmd and utils.get_event_bind_js are tested but need need more rigorous testing to be sure it won't break.

analytical/context_providers/matomo.py

@@ -0,0 +1,34 @@
+import utils
+from django.conf import settings
+
+def matomo_consent_provider(request):
+    """
+    Add Mamoto consent script to the requests context.
+    :Cases:
+        - If MATOMO_REQURE_CONSENT is True OR If ALWAYS_TRACK_REGISTERED True == continue on
+        - If ALWAYS_TRACK_REGISTERED is True AND the user is authenticated
+    """
+    # Do we require consent?
+    if getattr(settings, 'MATOMO_REQUIRE_CONSENT', False):
+        provide_script = True
+        if request.user.is_authenticated and not getattr(settings, "ALWAYS_TRACK_REGISTERED", True):
+            provide_script = False
+        if provide_script:
+            grant_class_name = getattr(settings, 'GRANT_CONSENT_TAG_CLASSNAME')
+            revoke_class_name = getattr(settings, 'REVOKE_CONSENT_CLASSNAME')
+            return {"consent_script":"""
+            %s;
+            %s
+            %s
+            """ % (
+                utils.build_paq_cmd('requireConsent'),
+                utils.get_event_bind_js(
+                    class_name=grant_class_name,
+                    matomo_event="rememberConsentGiven",
+                ),
+                utils.get_event_bind_js(
+                    class_name=revoke_class_name,
+                    matomo_event="forgetConsentGiven",
+                )
+            )}
+    return {'consent_script': ""}

analytical/templatetags/matomo.py

@@ -7,15 +7,12 @@ from collections import namedtuple
 from itertools import chain
 
 from django.conf import settings
-from django.template import Library, Node, TemplateSyntaxError
-
+from django.template import Library, Node, TemplateSyntaxError, Template
 from analytical.utils import (
     disable_html,
     get_identity,
     get_required_setting,
-    is_internal_ip,
-    build_paq_cmd,
-    get_event_bind_js
+    is_internal_ip
 )
 
 # domain name (characters separated by a dot), optional port, optional URI path, no slash
@@ -97,19 +94,6 @@ class MatomoNode(Node):
         if getattr(settings, 'MATOMO_DISABLE_COOKIES', False):
             commands.append(DISABLE_COOKIES_CODE)
 
-        if getattr(settings, "MATOMO_REQUIRE_CONSENT", False):
-            grant_class_name = settings.GRANT_CONSENT_TAG_CLASSNAME
-            revoke_class_name = settings.REVOKE_CONSENT_CLASSNAME
-            commands.append(build_paq_cmd('requireConsent'))
-            commands.append(get_event_bind_js(
-                class_name=grant_class_name,
-                matomo_event="rememberConsentGiven",
-            ))
-            commands.append(get_event_bind_js(
-                class_name=revoke_class_name,
-                matomo_event="forgetConsentGiven",
-            ))
-
         userid = get_identity(context, 'matomo')
         if userid is not None:
             variables_code = chain(variables_code, (
@@ -122,8 +106,14 @@ class MatomoNode(Node):
             'variables': '\n  '.join(variables_code),
             'commands': '\n  '.join(commands)
         }
+        # Force the consent script to render so we can inject it into the template
+        consent_script = Template("{{consent_script}}").render(context)
+        if len(consent_script) > 1:
+            html += consent_script
+
         if is_internal_ip(context, 'MATOMO'):
             html = disable_html(html, 'Matomo')
+
         return html
 
 

analytical/utils.py

@@ -167,8 +167,8 @@ class AnalyticalException(Exception):
 def build_paq_cmd(cmd, args=[]):
     """
     :Args:
-        - cmd -> The command to be pushed to paq (i.e enableHeartbeatTimer or contentInteraction)
-        - args -> Arguments to be added to the paq command. This is mainly
+        - cmd: The command to be pushed to paq (i.e enableHeartbeatTimer or contentInteraction)
+        - args: Arguments to be added to the paq command. This is mainly
             used when building commands to be used on manual event trigger.
         
     :Returns:
@@ -176,12 +176,12 @@ def build_paq_cmd(cmd, args=[]):
     """
     def __to_js_arg(arg):
         """
+        Turn 'arg' into its javascript counter-part
         :Args:
-            - arg: The variable (Matomo argument) to be converted to JS.
+            - arg: the argument that's to be passed to the array in _paq.push()
         :Return:
-            Javascript version of the passed arg parameter
+            The javascript counter-part to the argument that was passed
         """
-        # Recursively handle dictionaries
         if isinstance(arg, dict):
             arg_cpy = deepcopy(arg)
             for k, v in arg_cpy.items():
@@ -196,18 +196,20 @@ def build_paq_cmd(cmd, args=[]):
         elif isinstance(arg, list):
             for elem_idx in range(len(arg)):
                 arg[elem_idx] = __to_js_arg(arg[elem_idx])
+
         return arg
 
-    paq = "_paq.push(['%s', " % (cmd)
+    paq = "_paq.push(['%s'" % (cmd)
     if len(args) > 0:
+        paq += ", "
         for arg_idx in range(len(args)):
             current_arg = __to_js_arg(args[arg_idx])
-            no_quotes = type(current_arg) in [bool, dict, list]
+            no_quotes = type(current_arg) in [bool, int, dict, list]
             if arg_idx == len(args)-1:
                 if no_quotes:
-                    segment = "%s])" % (current_arg)
+                    segment = "%s]);" % (current_arg)
                 else:
-                    segment = "'%s'])" % (current_arg)
+                    segment = "'%s']);" % (current_arg)
             else:
                 if no_quotes:
                     segment = "%s, "% (current_arg)
@@ -215,7 +217,7 @@ def build_paq_cmd(cmd, args=[]):
                     segment = "'%s', " % (current_arg)
             paq += segment
     else:
-        paq += "])"
+        paq += "]);"        
     return paq
 
 def get_event_bind_js(
@@ -248,4 +250,3 @@ def get_event_bind_js(
     }}
     """ % (class_name, js_event, build_paq_cmd(matomo_event, matomo_args))
     return script
-