bugfix: Do not send HTTP request when creating a local notification

README.md

@@ -32,7 +32,18 @@ An object allowing a User to be notified of any change on a resource or a contai
 | `object` | `URLField` |         | ID of the resource or the container to watch                 |
 | `inbox`  | `URLField` |         | ID of the inbox to notify when the resource or the container change |
 
+# Middlewares
 
+There is a `CurrentUserMiddleware` that catches the connected user of the last performed HTTP request and adds 
+to every model before it is saved. This is useful if you need to get the connected user that performed 
+the last HTTP request in a `pre_saved` signal. You can get it by using the following line :
+
+```python
+getattr(instance, MODEL_MODIFICATION_USER_FIELD, "Unknown user")
+```
+
+`MODEL_MODIFICATION_USER_FIELD` is a constant that lies in `djangoldp_notification.middlewares` and 
+`instance` is the instance of your model before save in DB.
 
 # Signals
 
@@ -40,8 +51,6 @@ An object allowing a User to be notified of any change on a resource or a contai
 
 When an object is saved, a notification is created for all the subscriptions related to this object.
 
-
-
 ## Send email when new notification
 
 When a notification is created, an email is sent to the user.

djangoldp_notification/middlewares.py

+from django.db.models import signals
+
+
+MODEL_MODIFICATION_USER_FIELD = 'modification_user'
+
+
+class CurrentUserMiddleware:
+    def __init__(self, get_response=None):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        self.process_request(request)
+        response = self.get_response(request)
+        signals.pre_save.disconnect(dispatch_uid=request)
+        return response
+
+    def process_request(self, request):
+        if request.method in ('GET', 'HEAD', 'OPTION'):
+            # this request shouldn't update anything
+            # so no signal handler should be attached
+            return
+
+        if hasattr(request, 'user') and request.user.is_authenticated():
+            user = request.user
+        else:
+            user = None
+
+        def _update_users(sender, instance, **kwargs):
+            setattr(instance, MODEL_MODIFICATION_USER_FIELD, user)
+
+        signals.pre_save.connect(_update_users, dispatch_uid=request, weak=False)

djangoldp_notification/models.py

@@ -16,6 +16,8 @@ from djangoldp.fields import LDPUrlField
 from djangoldp.models import Model
 
 from django.template import loader
+
+from djangoldp_notification.middlewares import MODEL_MODIFICATION_USER_FIELD
 from .permissions import InboxPermissions
 
 
@@ -47,32 +49,42 @@ class Subscription(Model):
     def __str__(self):
         return '{}'.format(self.object)
 
-
 # --- SUBSCRIPTION SYSTEM ---
 @receiver(post_save, dispatch_uid="callback_notif")
-def send_notification(sender, instance, **kwargs):
+def send_notification(sender, instance, created, **kwargs):
     if sender != Notification:
         threads = []
         try:
-            urlContainer = settings.BASE_URL + Model.container_id(instance)
-            urlResource = settings.BASE_URL + Model.resource_id(instance)
+            url_container = settings.BASE_URL + Model.container_id(instance)
+            url_resource = settings.BASE_URL + Model.resource_id(instance)
         except NoReverseMatch:
             return
 
-        for subscription in Subscription.objects.filter(models.Q(object=urlResource)|models.Q(object=urlContainer)):
-            process = Thread(target=send_request, args=[subscription.inbox, urlResource])
+        for subscription in Subscription.objects.filter(models.Q(object=url_resource) | models.Q(object=url_container)):
+            process = Thread(target=send_request, args=[subscription.inbox, url_resource, instance, created])
             process.start()
             threads.append(process)
 
 
-def send_request(target, object_iri):
+def send_request(target, object_iri, instance, created):
+    unknown = _("Unknown author")
+    author = getattr(getattr(instance, MODEL_MODIFICATION_USER_FIELD, unknown), "urlid", unknown)
+    request_type = "creation" if created else "update"
+
     try:
-        req = requests.post(target,
-                            json={"@context": "https://cdn.happy-dev.fr/owl/hdcontext.jsonld",
-                                  "object": object_iri, "type": "update"},
-                            headers={"Content-Type": "application/ld+json"})
-    except:
-        logging.error('Djangoldp_notifications: Error with request')
+        if target.startswith(settings.SITE_URL):
+            user = Model.resolve_parent(target.replace(settings.SITE_URL, ''))
+            Notification.objects.create(user=user, object=object_iri, type=request_type, author=author)
+        else:
+            json = {
+                "@context": settings.LDP_RDF_CONTEXT,
+                "object": object_iri,
+                "author": author,
+                "type": request_type
+            }
+            requests.post(target, json=json, headers={"Content-Type": "application/ld+json"})
+    except Exception as e:
+        logging.error('Djangoldp_notifications: Error with request: {}'.format(e))
     return True
 
 
@@ -81,7 +93,7 @@ def send_email_on_notification(sender, instance, created, **kwargs):
     if created and instance.summary and settings.JABBER_DEFAULT_HOST and instance.user.email:
         try:
             if instance.author.startswith(settings.SITE_URL):
-                who = str(Model.resolve_id(instance.author.replace(settings.SITE_URL,'')))
+                who = str(Model.resolve_id(instance.author.replace(settings.SITE_URL, '')))
             else:
                 who = requests.get(instance.author).json()['name']
         except:
@@ -89,13 +101,13 @@ def send_email_on_notification(sender, instance, created, **kwargs):
 
         try:
             if instance.object.startswith(settings.SITE_URL):
-                where = str(Model.resolve_id(instance.object.replace(settings.SITE_URL,'')))
+                where = str(Model.resolve_id(instance.object.replace(settings.SITE_URL, '')))
             else:
                 where = requests.get(instance.object).json()['name']
         except:
             where = "Unknown place"
 
-        if(who == where):
+        if who == where:
             where = "has sent you a private message"
         else:
             where = "mention you on " + where