XEP-0277: new preview/mbPreview method:

This method does more or less the same thing as sending, but without actually sending the
item, and parse the generated element just after. This way, the triggers are run, and a
preview of the item can be made for the resulting microblog data.

sat/plugins/plugin_xep_0277.py

@@ -99,6 +99,14 @@ class XEP_0277(object):
             method=self._mbSend,
             async_=True,
         )
+        host.bridge.addMethod(
+            "mbPreview",
+            ".plugin",
+            in_sign="ssss",
+            out_sign="s",
+            method=self._mbPreview,
+            async_=True,
+        )
         host.bridge.addMethod(
             "mbRetract",
             ".plugin",
@@ -651,7 +659,7 @@ class XEP_0277(object):
 
         defer.returnValue(item_elt)
 
-    ## publish ##
+    ## publish/preview ##
 
     def getCommentsNode(self, item_id):
         """Generate comment node
@@ -803,27 +811,32 @@ class XEP_0277(object):
                         client, comments_service, comments_node, comments_affiliations
                     )
 
-    def _mbSend(self, service, node, data, profile_key):
-        service = jid.JID(service) if service else None
-        node = node if node else NS_MICROBLOG
-        client = self.host.getClient(profile_key)
-        data = data_format.deserialise(data)
-        return self.send(client, data, service, node)
-
     def friendlyId(self, data):
         """Generate a user friendly id from title or content"""
         id_base = regex.urlFriendlyText(data.get('title') or data.get('content', ''))
         return f"{id_base}-{token_urlsafe(3)}"
 
-    @defer.inlineCallbacks
-    def send(self, client, data, service=None, node=NS_MICROBLOG):
+    def _mbSend(self, service, node, data, profile_key):
+        service = jid.JID(service) if service else None
+        node = node if node else NS_MICROBLOG
+        client = self.host.getClient(profile_key)
+        data = data_format.deserialise(data)
+        return defer.ensureDeferred(self.send(client, data, service, node))
+
+    async def send(
+        self,
+        client: SatXMPPEntity,
+        data: dict,
+        service: Optional[jid.JID] = None,
+        node: Optional[str] = NS_MICROBLOG
+    ) -> None:
         """Send XEP-0277's microblog data
 
-        @param data(dict): microblog data (must include at least a "content" or a "title" key).
+        @param data: microblog data (must include at least a "content" or a "title" key).
             see http://wiki.goffi.org/wiki/Bridge_API_-_Microblogging/en for details
-        @param service(jid.JID, None): PubSub service where the microblog must be published
+        @param service: PubSub service where the microblog must be published
             None to publish on profile's PEP
-        @param node(unicode, None): PubSub node to use (defaut to microblog NS)
+        @param node: PubSub node to use (defaut to microblog NS)
             None is equivalend as using default value
         """
         # TODO: check that all data keys are used, this would avoid sending publicly a private message
@@ -839,12 +852,43 @@ class XEP_0277(object):
                 item_id = str(shortuuid.uuid())
 
         try:
-            yield self._manageComments(client, data, service, node, item_id, access=None)
+            await self._manageComments(client, data, service, node, item_id, access=None)
         except error.StanzaError:
             log.warning("Can't create comments node for item {}".format(item_id))
-        item = yield self.data2entry(client, data, item_id, service, node)
-        ret = yield self._p.publish(client, service, node, [item])
-        defer.returnValue(ret)
+        item = await self.data2entry(client, data, item_id, service, node)
+        return await self._p.publish(client, service, node, [item])
+
+    def _mbPreview(self, service, node, data, profile_key):
+        service = jid.JID(service) if service else None
+        node = node if node else NS_MICROBLOG
+        client = self.host.getClient(profile_key)
+        data = data_format.deserialise(data)
+        d = defer.ensureDeferred(self.preview(client, data, service, node))
+        d.addCallback(data_format.serialise)
+        return d
+
+    async def preview(
+        self,
+        client: SatXMPPEntity,
+        data: dict,
+        service: Optional[jid.JID] = None,
+        node: Optional[str] = NS_MICROBLOG
+    ) -> dict:
+        """Preview microblog data without publishing them
+
+        params are the same as for [send]
+        @return: microblog data as would be retrieved from published item
+        """
+        if node is None:
+            node = NS_MICROBLOG
+
+        item_id = data.get("id", "")
+
+        # we have to serialise then deserialise to be sure that all triggers are called
+        item_elt = await self.data2entry(client, data, item_id, service, node)
+        item_elt.uri = pubsub.NS_PUBSUB
+        return await self.item2mbdata(client, item_elt, service, node)
+
 
     ## retract ##