add a general context checker

InvenTree/common/notifications.py

@@ -18,8 +18,10 @@ logger = logging.getLogger('inventree')
 # region base classes
 class NotificationMethod:
     METHOD_NAME = ''
+    CONTEXT_BUILTIN = ['name', 'message', ]
+    CONTEXT_EXTRA = []
 
-    def __init__(self, obj, entry_name, receivers) -> None:
+    def __init__(self, obj, entry_name, receivers, context) -> None:
         # Check if a sending fnc is defined
         if (not hasattr(self, 'send')) and (not hasattr(self, 'send_bulk')):
             raise NotImplementedError('A NotificationMethod must either define a `send` or a `send_bulk` method')
@@ -32,10 +34,46 @@ class NotificationMethod:
         self.obj = obj
         self.entry_name = entry_name
         self.receivers = receivers
+        self.context = self.check_context(context)
 
         # Gather recipients
         self.recipients = self.get_recipients()
 
+    def check_context(self, context):
+        def check(ref, obj):
+            # the obj is not accesible so we are on the end
+            if not isinstance(obj, (list, dict, tuple, )):
+                return ref
+
+            # check if the ref exsists
+            if isinstance(ref, str):
+                if not obj.get(ref):
+                    return ref
+                return False
+
+            # nested
+            elif isinstance(ref, (tuple, list)):
+                if len(ref) == 1:
+                    return check(ref[0], obj)
+                ret = check(ref[0], obj)
+                if ret:
+                    return ret
+                return check(ref[1:], obj[ref[0]])
+
+            # other cases -> raise
+            raise NotImplementedError('This type can not be used as a context reference')
+
+        missing = []
+        for item in (*self.CONTEXT_BUILTIN, *self.CONTEXT_EXTRA):
+            ret = check(item, context)
+            if ret:
+                missing.append(ret)
+
+        if missing:
+            raise NotImplementedError(f'The `context` is missing the following items:\n{missing}')
+
+        return context
+
     def get_recipients(self):
         raise NotImplementedError('The `get_recipients` method must be implemented!')
 
@@ -50,12 +88,12 @@ class NotificationMethod:
 
 
 class SingleNotificationMethod(NotificationMethod):
-    def send(self, receiver, context):
+    def send(self, receiver):
         raise NotImplementedError('The `send` method must be overriden!')
 
 
 class BulkNotificationMethod(NotificationMethod):
-    def send_bulk(self, context):
+    def send_bulk(self):
         raise NotImplementedError('The `send` method must be overriden!')
 # endregion
 
@@ -63,26 +101,22 @@ class BulkNotificationMethod(NotificationMethod):
 # region implementations
 class EmailNotification(BulkNotificationMethod):
     METHOD_NAME = 'mail'
+    CONTEXT_EXTRA = [
+        ('template', ),
+        ('template', 'html', ),
+        ('template', 'subject', ),
+    ]
 
     def get_recipients(self):
         return EmailAddress.objects.filter(
             user__in=self.receivers,
         )
 
-    def send_bulk(self, context):
-        # TODO: In the future, include the part image in the email template
-
-        if 'template' not in context:
-            raise NotImplementedError('Templates must be provided in the `context`')
-        if 'html' not in context['template']:
-            raise NotImplementedError("template['html'] must be provided in the `context`")
-        if 'subject' not in context['template']:
-            raise NotImplementedError("template['subject'] must be provided in the `context`")
-
-        html_message = render_to_string(context['template']['html'], context)
+    def send_bulk(self):
+        html_message = render_to_string(self.context['template']['html'], self.context)
         recipients = self.recipients.values_list('email', flat=True)
 
-        InvenTree.tasks.send_email(context['template']['subject'], '', recipients, html_message=html_message)
+        InvenTree.tasks.send_email(self.context['template']['subject'], '', recipients, html_message=html_message)
 
         return True
 
@@ -92,14 +126,14 @@ class UIMessageNotification(SingleNotificationMethod):
     def get_recipients(self):
         return self.receivers
 
-    def send(self, receiver, context):
+    def send(self, receiver):
         NotificationMessage.objects.create(
             target_object = self.obj,
             source_object = receiver,
             user = receiver,
             category = self.entry_name,
-            name = context['name'],
-            message = context['message'],
+            name = self.context['name'],
+            message = self.context['message'],
         )
 # endregion
 # endregion
@@ -165,7 +199,7 @@ def trigger_notifaction(obj, entry_name=None, obj_ref='pk', receivers=None, rece
 
 def deliver_notification(cls: NotificationMethod, obj, entry_name: str, receivers, notification_context: dict):
     # Init delivery method
-    method = cls(obj, entry_name, receivers)
+    method = cls(obj, entry_name, receivers, notification_context)
 
     if method.recipients and len(method.recipients) > 0:
         # Log start
@@ -179,12 +213,12 @@ def deliver_notification(cls: NotificationMethod, obj, entry_name: str, receiver
 
         # Select delivery method and execute it
         if hasattr(method, 'send_bulk'):
-            success = method.send_bulk(notification_context)
+            success = method.send_bulk()
             success_count = len(method.recipients)
 
         elif hasattr(method, 'send'):
             for rec in method.recipients:
-                if method.send(rec, notification_context):
+                if method.send(rec):
                     success_count += 1
                 else:
                     success = False