--- a/src/plugins/plugin_comp_file_sharing.py	Fri Mar 16 17:06:35 2018 +0100
+++ b/src/plugins/plugin_comp_file_sharing.py	Fri Mar 16 18:43:11 2018 +0100
@@ -23,6 +23,7 @@
 from sat.core.log import getLogger
 log = getLogger(__name__)
 from sat.tools.common import regex
+from sat.tools.common import uri
 from sat.tools import stream
 from twisted.internet import defer
 from twisted.words.protocols.jabber import error
@@ -48,6 +49,7 @@
 }
 
 HASH_ALGO = u'sha-256'
+NS_COMMENTS = 'org.salut-a-toi.comments'
 COMMENT_NODE_PREFIX = 'org.salut-a-toi.file_comments/'
 
 
@@ -62,6 +64,9 @@
         self._t = host.plugins['XEP-0264']
         host.trigger.add("FILE_getDestDir", self._getDestDirTrigger)
         host.trigger.add("XEP-0234_fileSendingRequest", self._fileSendingRequestTrigger, priority=1000)
+        host.trigger.add("XEP-0234_buildFileElement", self._addFileComments)
+        host.trigger.add("XEP-0234_parseFileElement", self._getFileComments)
+        host.trigger.add("XEP-0329_compGetFilesFromNode", self._addCommentsData)
         self.files_path = host.getLocalPath(None, C.FILES_DIR, profile=False)
 
     def getHandler(self, client):
@@ -77,6 +82,11 @@
 
     @defer.inlineCallbacks
     def _fileTransferedCb(self, dummy, client, peer_jid, file_data, file_path):
+        """post file reception tasks
+
+        on file is received, this method create hash/thumbnails if necessary
+        move the file to the right location, and create metadata entry in database
+        """
         name = file_data[u'name']
         extra = {}
 
@@ -126,6 +136,7 @@
                                  extra=extra)
 
     def _getDestDirTrigger(self, client, peer_jid, transfer_data, file_data, stream_object):
+        """This trigger accept file sending request, and store file locally"""
         if not client.is_component:
             return True, None
         assert stream_object
@@ -143,6 +154,7 @@
 
     @defer.inlineCallbacks
     def _retrieveFiles(self, client, session, content_data, content_name, file_data, file_elt):
+        """This method retrieve a file on request, and send if after checking permissions"""
         peer_jid = session[u'peer_jid']
         try:
             found_files = yield self.host.memory.getFiles(client,
@@ -192,8 +204,43 @@
         else:
             return False, self._retrieveFiles(client, session, content_data, content_name, file_data, file_elt)
 
+    ## comments triggers ##
+
+    def _addFileComments(self, file_elt, extra_args):
+        try:
+            comments_url = extra_args.pop('comments_url')
+        except KeyError:
+            return
+
+        comment_elt = file_elt.addElement((NS_COMMENTS, 'comments'), content=comments_url)
+
+        try:
+            count = len(extra_args[u'extra'][u'comments'])
+        except KeyError:
+            count = 0
+
+        comment_elt['count'] = unicode(count)
+        return True
+
+    def _getFileComments(self, file_elt, file_data):
+        try:
+            comments_elt = next(file_elt.elements(NS_COMMENTS, 'comments'))
+        except StopIteration:
+            return
+        file_data['comments_url'] = unicode(comments_elt)
+        file_data['comments_count'] = comments_elt['count']
+        return True
+
+    def _addCommentsData(self, client, iq_elt, owner, node_path, files_data):
+        for file_data in files_data:
+            file_data['comments_url'] = uri.buildXMPPUri('pubsub',
+                                                         path=client.jid.full(),
+                                                         node=COMMENT_NODE_PREFIX + file_data['id'])
+        return True
+
 
 class Comments_handler(pubsub.PubSubService):
+    """This class is a minimal Pubsub service handling virtual nodes for comments"""
 
     def __init__(self, plugin_parent):
         super(Comments_handler, self).__init__() # PubsubVirtualResource())

--- a/src/plugins/plugin_xep_0264.py	Fri Mar 16 17:06:35 2018 +0100
+++ b/src/plugins/plugin_xep_0264.py	Fri Mar 16 18:43:11 2018 +0100
@@ -91,6 +91,7 @@
             width, height = thumbnail['size']
             thumbnail_elt['width'] = unicode(width)
             thumbnail_elt['height'] = unicode(height)
+        return True
 
     def _getFileThumbnails(self, file_elt, file_data):
         thumbnails = []
@@ -113,6 +114,7 @@
 
         if thumbnails:
             file_data.setdefault('extra', {})[C.KEY_THUMBNAILS] = thumbnails
+        return True
 
     ## thumbnails generation ##
 

--- a/src/plugins/plugin_xep_0329.py	Fri Mar 16 17:06:35 2018 +0100
+++ b/src/plugins/plugin_xep_0329.py	Fri Mar 16 18:43:11 2018 +0100
@@ -423,6 +423,11 @@
 
     @defer.inlineCallbacks
     def _compGetFilesFromNodeCb(self, client, iq_elt, owner, node_path):
+        """retrieve files from local files repository according to permissions
+
+        result stanza is then built and sent to requestor
+        @trigger XEP-0329_compGetFilesFromNode(client, iq_elt, owner, node_path, files_data): can be used to add data/elements
+        """
         peer_jid = jid.JID(iq_elt['from'])
         try:
             files_data = yield self.host.memory.getFiles(client, peer_jid=peer_jid, path=node_path, owner=owner)
@@ -432,6 +437,8 @@
         iq_result_elt = xmlstream.toResponse(iq_elt, 'result')
         query_elt = iq_result_elt.addElement((NS_FIS, 'query'))
         query_elt[u'node'] = node_path
+        if not self.host.trigger.point(u'XEP-0329_compGetFilesFromNode', client, iq_elt, owner, node_path, files_data):
+            return
         for file_data in files_data:
             file_elt = self._jf.buildFileElementFromDict(file_data,
                                                          modified=file_data.get(u'modified', file_data[u'created']))