From b729b012b1d7928212872bef2620e34217a363ca Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Jun 18 2015 11:04:26 +0000
Subject: Add a new endpoint streaming information about a given issue


This endpoint streams all information about a given issue put in the
redis queue and sends it to the browser.

The browser can then listen to this stream and adjust the UI on the fly

---

diff --git a/pagure/ui/issues.py b/pagure/ui/issues.py
index bd80924..cf8ee0e 100644
--- a/pagure/ui/issues.py
+++ b/pagure/ui/issues.py
@@ -21,8 +21,8 @@ import mimetypes
 import pagure.doc_utils
 import pagure.lib
 import pagure.forms
-from pagure import (APP, SESSION, LOG, __get_file_in_tree, cla_required,
-                    is_repo_admin, authenticated)
+from pagure import (APP,  SESSION, REDIS, LOG, __get_file_in_tree,
+                    cla_required, is_repo_admin, authenticated)
 
 
 # pylint: disable=E1101
@@ -497,6 +497,42 @@ def view_issue(repo, issueid, username=None):
     )
 
 
+@APP.route('/<repo>/issue/<int:issueid>/stream')
+@APP.route('/fork/<username>/<repo>/issue/<int:issueid>/stream')
+def stream_issue(repo, issueid, username=None):
+    """ Streams the changes made to an issue live
+    """
+
+    repo = pagure.lib.get_project(SESSION, repo, user=username)
+
+    if repo is None:
+        flask.abort(404, 'Project not found')
+
+    if not repo.settings.get('issue_tracker', True):
+        flask.abort(404, 'No issue tracker found for this project')
+
+    issue = pagure.lib.search_issues(SESSION, repo, issueid=issueid)
+
+    if issue is None or issue.project != repo:
+        flask.abort(404, 'Issue not found')
+
+    if issue.private and not is_repo_admin(repo) \
+            and (not authenticated() or
+                 not issue.user.user == flask.g.fas_user.username):
+        flask.abort(
+            403, 'This issue is private and you are not allowed to view it')
+
+    pubsub = REDIS.pubsub()
+    pubsub.subscribe(issue.uid)
+    def event_stream(pubsub):
+        for message in pubsub.listen():
+            yield 'data: %s\n\n' % message['data']
+
+    return flask.Response(
+        event_stream(pubsub),
+        mimetype="text/event-stream")
+
+
 @APP.route('/<repo>/issue/<int:issueid>/drop', methods=['POST'])
 @APP.route('/fork/<username>/<repo>/issue/<int:issueid>/drop',
            methods=['POST'])