Send all data to the client at startup

CHANGELOG

@@ -95,6 +95,8 @@ Other:
 - Added new caching system with support for Redis.
 - Support https as websocket protocol (wss).
 - Added migration path from 2.0.
+- Add an api for apps to send data when the websocket connection is established.
+- Used this api for all models expect of users to send all data to the client.
 
 
 Version 2.0 (2016-04-18)

openslides/agenda/apps.py

@@ -35,3 +35,7 @@ class AgendaAppConfig(AppConfig):
 
         # Register viewsets.
         router.register(self.get_model('Item').get_collection_string(), ItemViewSet)
+
+    def get_startup_elements(self):
+        from ..utils.collection import Collection
+        return [Collection(self.get_model('Item').get_collection_string())]

openslides/assignments/apps.py

@@ -24,3 +24,7 @@ class AssignmentsAppConfig(AppConfig):
         # Register viewsets.
         router.register(self.get_model('Assignment').get_collection_string(), AssignmentViewSet)
         router.register('assignments/poll', AssignmentPollViewSet)
+
+    def get_startup_elements(self):
+        from ..utils.collection import Collection
+        return [Collection(self.get_model('Assignment').get_collection_string())]

openslides/core/apps.py

@@ -14,10 +14,10 @@ class CoreAppConfig(AppConfig):
 
         # Import all required stuff.
         from django.db.models import signals
-        from openslides.core.config import config
+        from .config import config
-        from openslides.core.signals import post_permission_creation
+        from .signals import post_permission_creation
-        from openslides.utils.rest_api import router
+        from ..utils.rest_api import router
-        from openslides.utils.search import index_add_instance, index_del_instance
+        from ..utils.search import index_add_instance, index_del_instance
         from .config_variables import get_config_variables
         from .signals import delete_django_app_permissions
         from .views import (
@@ -55,3 +55,10 @@ class CoreAppConfig(AppConfig):
         signals.m2m_changed.connect(
             index_add_instance,
             dispatch_uid='m2m_index_add_instance')
+
+    def get_startup_elements(self):
+        from .config import config
+        from ..utils.collection import Collection
+        for model in ('Projector', 'ChatMessage', 'Tag', 'ProjectorMessage', 'Countdown'):
+            yield Collection(self.get_model(model).get_collection_string())
+        yield Collection(config.get_collection_string())

openslides/mediafiles/apps.py

@@ -18,3 +18,7 @@ class MediafilesAppConfig(AppConfig):
 
         # Register viewsets.
         router.register(self.get_model('Mediafile').get_collection_string(), MediafileViewSet)
+
+    def get_startup_elements(self):
+        from ..utils.collection import Collection
+        return [Collection(self.get_model('Mediafile').get_collection_string())]

openslides/motions/apps.py

@@ -34,3 +34,8 @@ class MotionsAppConfig(AppConfig):
         router.register(self.get_model('MotionChangeRecommendation').get_collection_string(),
                         MotionChangeRecommendationViewSet)
         router.register('motions/motionpoll', MotionPollViewSet)
+
+    def get_startup_elements(self):
+        from ..utils.collection import Collection
+        for model in ('Category', 'Motion', 'MotionBlock', 'Workflow', 'MotionChangeRecommendation'):
+            yield Collection(self.get_model(model).get_collection_string())

openslides/topics/apps.py

@@ -18,3 +18,7 @@ class TopicsAppConfig(AppConfig):
 
         # Register viewsets.
         router.register(self.get_model('Topic').get_collection_string(), TopicViewSet)
+
+    def get_startup_elements(self):
+        from ..utils.collection import Collection
+        return [Collection(self.get_model('Topic').get_collection_string())]

openslides/utils/autoupdate.py

@@ -4,6 +4,7 @@ from collections import Iterable
 from asgiref.inmemory import ChannelLayer
 from channels import Channel, Group
 from channels.auth import channel_session_user, channel_session_user_from_http
+from django.apps import apps
 from django.db import transaction
 
 from ..core.config import config
@@ -19,12 +20,33 @@ def ws_add_site(message):
     Adds the websocket connection to a group specific to the connecting user.
 
     The group with the name 'user-None' stands for all anonymous users.
+
+    Send all "starup-data" through the connection.
     """
     Group('site').add(message.reply_channel)
     message.channel_session['user_id'] = message.user.id
     # Saves the reply channel to the user. Uses 0 for anonymous users.
     websocket_user_cache.add(message.user.id or 0, message.reply_channel.name)
-    message.reply_channel.send({"accept": True})
+
+    # Collect all elements that shoud be send to the client when the websocket
+    # connection is established
+    output = []
+    for app in apps.get_app_configs():
+        try:
+            # Get the method get_startup_elements() from an app.
+            # This method has to return an iterable of Collection objects.
+            get_startup_elements = app.get_startup_elements
+        except AttributeError:
+            # Skip apps that do not implement get_startup_elements
+            continue
+        for collection in get_startup_elements():
+            output.extend(collection.as_autoupdate_for_user(message.user))
+
+    # Send all data. If there is no data, then onyl accept the connection
+    if output:
+        message.reply_channel.send({'text': json.dumps(output)})
+    else:
+        message.reply_channel.send({"accept": True})
 
 
 @channel_session_user

openslides/utils/collection.py

@@ -352,6 +352,17 @@ class Collection:
             output.append(content)
         return output
 
+    def as_autoupdate_for_user(self, user):
+        """
+        Returns a list of dicts, that can be send though the websocket to a user.
+        """
+        output = []
+        for collection_element in self.element_generator():
+            content = collection_element.as_autoupdate_for_user(user)
+            if content is not None:
+                output.append(content)
+        return output
+
     def as_list_for_user(self, user):
         """
         Returns a list of dictonaries to send them to a user, for example over