add realtime update notification

websocket_server.js

@@ -0,0 +1,32 @@
+
+var WebSocketServer = require('ws').Server;
+var Redis = require('redis');
+
+var port = 8077;
+
+var wss = new WebSocketServer({port: port});
+
+wss.on('connection', function(ws) {
+  // console.log("New websockets connection");
+  ws.on('message', function(channel) {
+    var redis = Redis.createClient(6379, 'localhost');
+    redis.subscribe(channel);
+    // console.log('Listening for comments on channel ' + channel);
+    redis.on('message', function (channel, message) {
+      console.log('Sent comment to channel ' + channel);
+      ws.send(message);
+    });
+    ws.on('close', function(){
+      // console.log('Killing listener for channel ' + channel);
+      redis.unsubscribe();
+      redis.end();
+    });
+    ws.on('error', function(){
+      // console.log('Killing listener for channel ' + channel);
+      redis.unsubscribe();
+      redis.end();
+    });
+  });
+});
+
+console.log("WebSocket Server Listening on port "+port);

woodwind/static/feed.js

@@ -66,7 +66,5 @@ $(function(){
         });
     }
 
-
-
     attachListeners();
 });

woodwind/static/websocket_client.js

@@ -0,0 +1,23 @@
+
+// topic will be woodwind::user:id or woodwind::feed:id
+function webSocketSubscribe(topic) {
+    if ('WebSocket' in window) {
+
+        var ws = new WebSocket(window.location.origin
+                               .replace(/https?:\/\//, 'ws://')
+                               .replace(/(:\d+)?$/, ':8077'));
+
+        ws.onopen = function(event) {
+            // send the topic
+            console.log('subscribing to topic: ' + topic);
+            ws.send(topic);
+        };
+
+        ws.onmessage = function(event) {
+            var data = JSON.parse(event.data);
+            data.entries.forEach(function(entryHtml) {
+                $('body main').prepend(entryHtml);
+            });
+        };
+    }
+}

woodwind/tasks.py

@@ -1,11 +1,13 @@
 from config import Config
 from contextlib import contextmanager
 from woodwind.models import Feed, Entry
+from redis import StrictRedis
 import bs4
 import celery
 import celery.utils.log
 import datetime
 import feedparser
+import json
 import mf2py
 import mf2util
 import re
@@ -27,6 +29,8 @@ logger = celery.utils.log.get_task_logger(__name__)
 engine = sqlalchemy.create_engine(Config.SQLALCHEMY_DATABASE_URI)
 Session = sqlalchemy.orm.sessionmaker(bind=engine)
 
+redis = StrictRedis()
+
 
 @contextmanager
 def session_scope():
@@ -65,7 +69,7 @@ def update_feed(feed_id):
 
 def process_feed(session, feed):
     now = datetime.datetime.utcnow()
-    found_new = False
+    new_entries = []
     try:
         logger.info('fetching feed: %s', feed)
         response = requests.get(feed.feed)
@@ -102,14 +106,17 @@ def process_feed(session, feed):
                 for in_reply_to in entry.get_property('in-reply-to', []):
                     fetch_reply_context.delay(entry.id, in_reply_to)
 
-                found_new = True
+                new_entries.append(entry)
             else:
                 logger.info('skipping previously seen post %s', old.permalink)
 
     finally:
         feed.last_checked = now
-        if found_new:
+        if new_entries:
             feed.last_updated = now
+        session.commit()
+        if new_entries:
+            notify_feed_updated(session, feed, new_entries)
 
 
 def check_push_subscription(session, feed, response):
@@ -168,6 +175,28 @@ def check_push_subscription(session, feed, response):
             send_request('subscribe', hub, topic)
 
 
+def notify_feed_updated(session, feed, entries):
+    """Render the new entries and publish them to redis
+    """
+    from . import create_app
+    from flask import render_template
+    import flask.ext.login as flask_login
+    flask_app = create_app()
+
+    for user in feed.users:
+        with flask_app.test_request_context():
+            flask_login.login_user(user, remember=True)
+            message = json.dumps({
+                'user': user.id,
+                'feed': feed.id,
+                'entries': [
+                    render_template('_entry.jinja2', feed=feed, entry=e)
+                    for e in entries
+                ],
+            })
+            redis.publish('woodwind:user:{}'.format(user.id), message)
+
+
 def is_content_equal(e1, e2):
     """The criteria for determining if an entry that we've seen before
     has been updated. If any of these fields have changed, we'll scrub the

woodwind/templates/_entry.jinja2

@@ -0,0 +1,50 @@
+{% for context in entry.reply_context %}
+  <article class="reply-context">
+    <header>
+      {% if context.author_photo %}
+        <img src="{{context.author_photo}}"/>
+      {% endif %}
+      {% if context.author_name %}
+        {{ context.author_name }} -
+      {% endif %}
+      {{ context.permalink | domain_for_url }}
+    </header>
+    {% if context.title %}
+      <h1>{{ context.title }}</h1>
+    {% endif %}
+    {% if context.content %}
+      <div>
+        {{ context.content_cleaned() | add_preview }}
+      </div>
+    {% endif %}
+    <footer>
+      <a href="{{ context.permalink }}">{{ context.published }}</a>
+    </footer>
+  </article>
+{% endfor %}
+
+<article>
+  <header>
+    {% if entry.author_photo %}
+      <img src="{{entry.author_photo}}"/>
+    {% endif %}
+    {% if entry.author_name %}
+      {{ entry.author_name }} -
+    {% endif %}
+    {{ entry.feed.name }}
+  </header>
+  {% if entry.title %}
+    <h1>{{ entry.title }}</h1>
+  {% endif %}
+  {% if entry.content %}
+    <div>
+      {{ entry.content_cleaned() | add_preview }}
+    </div>
+  {% endif %}
+  <footer>
+    <a href="{{ entry.permalink }}">{{ entry.published }}</a>
+    <div class="reply-area">
+      {% include '_reply.jinja2' with context %}
+    </div>
+  </footer>
+</article>

woodwind/templates/feed.jinja2

@@ -1,6 +1,7 @@
 {% extends "base.jinja2" %}
 {% block head %}
   <script src="{{url_for('static', filename='feed.js', version='2015-02-19')}}"></script>
+  <script src="{{ url_for('static', filename='websocket_client.js', version='2015-02-22') }}"></script>
 
   {% if current_user and current_user.settings
         and current_user.settings.get('reply-method') == 'indie-config' %}
@@ -21,56 +22,7 @@
 {% block body %}
 
   {% for entry in entries %}
-    {% for context in entry.reply_context %}
-      <article class="reply-context">
-        <header>
-          {% if context.author_photo %}
-            <img src="{{context.author_photo}}"/>
-          {% endif %}
-          {% if context.author_name %}
-            {{ context.author_name }} -
-          {% endif %}
-          {{ context.permalink | domain_for_url }}
-        </header>
-        {% if context.title %}
-          <h1>{{ context.title }}</h1>
-        {% endif %}
-        {% if context.content %}
-          <div>
-            {{ context.content_cleaned() | add_preview }}
-          </div>
-        {% endif %}
-        <footer>
-          <a href="{{ context.permalink }}">{{ context.published }}</a>
-        </footer>
-      </article>
-    {% endfor %}
-
-    <article>
-      <header>
-        {% if entry.author_photo %}
-          <img src="{{entry.author_photo}}"/>
-        {% endif %}
-        {% if entry.author_name %}
-          {{ entry.author_name }} -
-        {% endif %}
-        {{ entry.feed.name }}
-      </header>
-      {% if entry.title %}
-        <h1>{{ entry.title }}</h1>
-      {% endif %}
-      {% if entry.content %}
-        <div>
-          {{ entry.content_cleaned() | add_preview }}
-        </div>
-      {% endif %}
-      <footer>
-        <a href="{{ entry.permalink }}">{{ entry.published }}</a>
-        <div class="reply-area">
-          {% include '_reply.jinja2' with context %}
-        </div>
-      </footer>
-    </article>
+    {% include '_entry.jinja2' with context %}
   {% endfor %}
 
   {% if entries %}
@@ -79,4 +31,10 @@
     </div>
   {% endif %}
 
+  {% if current_user %}
+    <script>
+      webSocketSubscribe('woodwind:user:' + {{ current_user.id }});
+    </script>
+  {% endif %}
+
 {% endblock body %}