Support for RSS feeds update events, solves #48

platypush/backend/http/request/__init__.py

@@ -24,12 +24,14 @@ class HttpRequest(object):
             self.kwargs = kwargs
 
 
-    def __init__(self, args, bus=None, poll_seconds=None, timeout=None, **kwargs):
+    def __init__(self, args, bus=None, poll_seconds=None, timeout=None,
+                 skip_first_call=True, **kwargs):
         super().__init__()
 
         self.poll_seconds = poll_seconds or self.poll_seconds
         self.timeout = timeout or self.timeout
         self.bus = bus
+        self.skip_first_call = skip_first_call
         self.last_request_timestamp = 0
 
         if isinstance(args, self.HttpRequestArguments):
@@ -62,7 +64,9 @@ class HttpRequest(object):
             else:
                 event = HttpEvent(dict(self), new_items)
 
-            if new_items and not is_first_call and self.bus:
+            if new_items and self.bus:
+                if not self.skip_first_call or (
+                        self.skip_first_call and not is_first_call):
                     self.bus.post(event)
 
             response.raise_for_status()

platypush/backend/http/request/rss/__init__.py

@@ -0,0 +1,147 @@
+import datetime
+import feedparser
+import logging
+import os
+import requests
+import time
+
+from sqlalchemy import create_engine, Column, Integer, String, DateTime, \
+    UniqueConstraint, ForeignKey
+
+from sqlalchemy.orm import sessionmaker, scoped_session
+from sqlalchemy.ext.declarative import declarative_base
+
+from platypush.backend.http.request import HttpRequest
+from platypush.config import Config
+from platypush.message.event.http.rss import NewFeedEvent
+from platypush.utils import mkdir_p
+
+Base = declarative_base()
+Session = scoped_session(sessionmaker())
+
+
+class GetRssUpdates(HttpRequest):
+    """ Gets new items in an RSS feed """
+
+    dbfile = os.path.join(os.path.expanduser(Config.get('workdir')), 'feeds', 'rss.db')
+
+    def __init__(self, url, headers=None, params=None, dbfile=None,
+                 mercury_api_key=None, *args, **kwargs):
+
+        self.url = url
+        self.mercury_api_key = mercury_api_key  # Mercury Reader API used to parse the content of the link
+
+        if dbfile: self.dbfile = dbfile
+        mkdir_p(os.path.dirname(self.dbfile))
+
+        self.engine = create_engine('sqlite:///{}'.format(self.dbfile))
+        Base.metadata.create_all(self.engine)
+        Session.configure(bind=self.engine)
+        self._get_or_create_source(session=Session())
+
+        request_args = {
+            'method': 'get',
+            'url': self.url,
+            'headers': headers or {},
+            'params': params or {},
+        }
+
+        super().__init__(*args, skip_first_call=False, args=request_args, **kwargs)
+
+
+    def _get_or_create_source(self, session):
+        record = session.query(FeedSource).filter_by(url=self.url).first()
+        if record is None:
+            record = FeedSource(url=self.url)
+            session.add(record)
+
+        session.commit()
+        return record
+
+
+    def _parse_entry_content(self, link):
+        response = None
+
+        try:
+            logging.info('Parsing content for {}'.format(link))
+            response = requests.get('https://mercury.postlight.com/parser',
+                                    params = {'url': link},
+                                    headers = {'x-api-key': self.mercury_api_key })
+        except Exception as e: logging.exception(e)
+
+        return response.json()['content'] if response and response.ok else None
+
+
+    def get_new_items(self, response):
+        feed = feedparser.parse(response.text)
+        session = Session()
+        source_record = self._get_or_create_source(session=session)
+        session.add(source_record)
+        parse_start_time = datetime.datetime.utcnow()
+
+        entries = []
+        last_updated_at = source_record.last_updated_at
+
+        if source_record.title != feed.feed['title']:
+            source_record.title = feed.feed['title']
+
+        for entry in feed.entries:
+            entry_timestamp = datetime.datetime(*entry.published_parsed[:6])
+
+            if last_updated_at is None: last_updated_at = entry_timestamp
+            if source_record.last_updated_at is None \
+                    or entry_timestamp > source_record.last_updated_at:
+                last_updated_at = max(entry_timestamp, last_updated_at)
+
+                entry.content = self._parse_entry_content(entry.link) \
+                    if self.mercury_api_key else None
+
+                e = {
+                    'entry_id': entry.id,
+                    'title': entry.title,
+                    'link': entry.link,
+                    'summary': entry.summary,
+                    'content': entry.content,
+                    'source_id': source_record.id,
+                    'published': entry_timestamp,
+                }
+
+                entries.append(e)
+                session.add(FeedEntry(**e))
+
+        source_record.last_updated_at = parse_start_time
+        session.commit()
+
+        if entries:
+            logging.info('Parsed {} new entries from the RSS feed {}'.format(
+                len(entries), source_record.title))
+
+        return NewFeedEvent(dict(self), entries)
+
+
+class FeedSource(Base):
+    __tablename__ = 'FeedSource'
+    __table_args__ = ({ 'sqlite_autoincrement': True })
+
+    id = Column(Integer, primary_key=True)
+    title = Column(String)
+    url = Column(String, unique=True)
+    last_updated_at = Column(DateTime)
+
+
+class FeedEntry(Base):
+    __tablename__ = 'FeedEntry'
+    __table_args__ = ({ 'sqlite_autoincrement': True })
+
+    id = Column(Integer, primary_key=True)
+    entry_id = Column(String)
+    source_id = Column(Integer, ForeignKey('FeedSource.id'), nullable=False)
+    title = Column(String)
+    link = Column(String)
+    summary = Column(String)
+    content = Column(String)
+    published = Column(DateTime)
+
+
+# vim:sw=4:ts=4:et:
+

platypush/config/__init__.py

@@ -1,11 +1,13 @@
 import datetime
-import errno
 import logging
 import os
 import socket
 import time
 import yaml
 
+from platypush.utils import mkdir_p
+
+
 """ Config singleton instance """
 _default_config_instance = None
 
@@ -237,12 +239,6 @@ class Config(object):
         _default_config_instance._config[key] = key
 
 
-def mkdir_p(path):
-    try: os.makedirs(path)
-    except OSError as exc:  # Python >2.5
-        if exc.errno == errno.EEXIST and os.path.isdir(path): pass
-        else: raise
-
 
 # vim:sw=4:ts=4:et:
 

platypush/message/event/http/rss.py

@@ -0,0 +1,9 @@
+from platypush.message.event.http import HttpEvent
+
+class NewFeedEvent(HttpEvent):
+    def __init__(self, request, response, *args, **kwargs):
+        super().__init__(request=request, response=response, *args, **kwargs)
+
+
+# vim:sw=4:ts=4:et:
+

platypush/utils/__init__.py

@@ -1,10 +1,9 @@
+import errno
 import importlib
 import logging
+import os
 import signal
 
-from platypush.config import Config
-from platypush.message import Message
-
 
 def get_module_and_method_from_action(action):
     """ Input  : action=music.mpd.play
@@ -65,5 +64,12 @@ def clear_timeout():
     signal.alarm(0)
 
 
+def mkdir_p(path):
+    try: os.makedirs(path)
+    except OSError as exc:  # Python >2.5
+        if exc.errno == errno.EEXIST and os.path.isdir(path): pass
+        else: raise
+
+
 # vim:sw=4:ts=4:et:
 

requirements.txt

@@ -20,6 +20,9 @@ sqlalchemy
 # Dates support
 python-dateutil
 
+# RSS feeds support
+feedparser
+
 # Philips Hue plugin support
 phue
 

setup.py

@@ -65,7 +65,8 @@ setup(
         'Support for Pushbullet backend': ['requests', 'websocket-client'],
         'Support for HTTP backend': ['flask'],
         'Support for HTTP poll backend': ['frozendict'],
-        'Support for database plugin': ['sqlalchemy', 'python-dateutil'],
+        'Support for database plugin': ['sqlalchemy'],
+        'Support for RSS feeds': ['feedparser'],
         'Support for Philips Hue plugin': ['phue'],
         'Support for MPD/Mopidy music server plugin': ['python-mpd2'],
         'Support for Belkin WeMo Switch plugin': ['ouimeaux'],