Added extension support and converted PodcastGenerator to extension

feedgen/__main__.py

@@ -9,7 +9,6 @@
 '''
 
 from feedgen.feed import FeedGenerator
-from feedgen.podcast import PodcastGenerator
 import sys
 
 
@@ -32,7 +31,7 @@ if __name__ == '__main__':
 
 	arg = sys.argv[1]
 
-	fg = PodcastGenerator() if arg.endswith('podcast') else FeedGenerator()
+	fg = FeedGenerator()
 	fg.id('http://lernfunk.de/_MEDIAID_123')
 	fg.title('Testfeed')
 	fg.author( {'name':'Lars Kiesow','email':'lkiesow@uos.de'} )
@@ -64,16 +63,21 @@ if __name__ == '__main__':
 	elif arg == 'rss':
 		print fg.rss_str(pretty=True)
 	elif arg == 'podcast':
-		fg.itunes_author('Lars Kiesow')
+		# Load the podcast extension. It will automatically be loaded for all
-		fg.itunes_category('Technology', 'Podcasting')
+		# entries in the feed, too. Thus also for our “fe”.
-		fg.itunes_explicit('no')
+		fg.load_extension('podcast')
-		fg.itunes_complete('no')
+		fg.podcast.itunes_author('Lars Kiesow')
-		fg.itunes_new_feed_url('http://example.com/new-feed.rss')
+		fg.podcast.itunes_category('Technology', 'Podcasting')
-		fg.itunes_owner('John Doe', 'john@example.com')
+		fg.podcast.itunes_explicit('no')
-		fg.itunes_summary('Lorem ipsum dolor sit amet, consectetur adipiscing elit. Verba tu fingas et ea dicas, quae non sentias?')
+		fg.podcast.itunes_complete('no')
-		fe.itunes_author('Lars Kiesow')
+		fg.podcast.itunes_new_feed_url('http://example.com/new-feed.rss')
+		fg.podcast.itunes_owner('John Doe', 'john@example.com')
+		fg.podcast.itunes_summary('Lorem ipsum dolor sit amet, ' + \
+				'consectetur adipiscing elit. ' + \
+				'Verba tu fingas et ea dicas, quae non sentias?')
+		fe.podcast.itunes_author('Lars Kiesow')
 
-		print fg.podcast_str(pretty=True)
+		print fg.rss_str(pretty=True)
 	elif arg.endswith('atom'):
 		fg.atom_file(arg)
 	elif arg.endswith('rss'):

feedgen/entry.py

@@ -50,8 +50,11 @@ class FeedEntry(object):
 	__rss_source = None
 	__rss_title = None
 
+	# Extension list:
+	__extensions = {}
 
-	def atom_entry(self, feed):
+
+	def atom_entry(self, feed, extensions=True):
 		'''Insert an ATOM entry into a existing XML structure. Normally you
 		would pass the feed node of an ATOM feed XML to this function.
 
@@ -139,10 +142,15 @@ class FeedEntry(object):
 			rights = etree.SubElement(feed, 'rights')
 			rights.text = self.__atom_rights
 
+		if extensions:
+			for ext in self.__extensions.values() or []:
+				if ext.get('atom'):
+					entry = ext['inst'].extend_atom(entry)
+
 		return entry
 
 
-	def rss_entry(self, feed):
+	def rss_entry(self, feed, extensions=True):
 		'''Insert an RSS item into a existing XML structure. Normally you
 		would pass the channel node of an RSS feed XML to this function.
 
@@ -184,6 +192,12 @@ class FeedEntry(object):
 			pubDate = etree.SubElement(channel, 'pubDate')
 			pubDate.text = self.__rss_pubDate.strftime(
 					'%a, %e %b %Y %H:%M:%S %z')
+
+		if extensions:
+			for ext in self.__extensions.values() or []:
+				if ext.get('rss'):
+					entry = ext['inst'].extend_rss(entry)
+
 		return entry
 
 
@@ -575,3 +589,34 @@ class FeedEntry(object):
 		if not ttl is None:
 			self.__rss_ttl = int(ttl)
 		return self.__rss_ttl
+
+	
+	def load_extension(self, name, atom=True, rss=True):
+		'''Load a specific extension by name.
+
+		:param name: Name of the extension to load.
+		:param atom: If the extension should be used for ATOM feeds.
+		:param rss: If the extension should be used for RSS feeds.
+		'''
+		# Check loaded extensions
+		if not isinstance(self.__extensions, dict):
+			self.__extensions = {}
+		if name in self.__extensions.keys():
+			raise ImportError('Extension already loaded')
+
+		# Load extension
+		extname = name[0].upper() + name[1:] + 'EntryExtension'
+
+		# Try to import extension from dedicated module for entry:
+		try:
+			supmod = __import__('feedgen.ext.%s_entry' % name)
+			extmod = getattr(supmod.ext, name + '_entry')
+		except ImportError:
+			# Try the FeedExtension module instead
+			supmod = __import__('feedgen.ext.%s' % name)
+			extmod = getattr(supmod.ext, name)
+
+		ext    = getattr(extmod, extname)
+		extinst = ext()
+		setattr(self, name, extinst)
+		self.__extensions[name] = {'inst':extinst,'atom':atom,'rss':rss}

feedgen/ext/__init__.py

@@ -0,0 +1,6 @@
+# -*- coding: utf-8 -*-
+"""
+	===========
+	feedgen.ext
+	===========
+"""

feedgen/ext/base.py

@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+'''
+	feedgen.ext.base
+	~~~~~~~~~~~~~~~~
+
+	Basic FeedGenerator which does nothing but provides all necessary methods.
+
+	:copyright: 2013, Lars Kiesow <lkiesow@uos.de>
+
+	:license: FreeBSD and LGPL, see license.* for more details.
+'''
+
+
+class BaseExtension(object):
+	'''Basic FeedGenerator extension.
+	'''
+
+	def extend_rss(self, feed):
+		'''Create an RSS feed xml structure containing all previously set fields.
+
+		:param feed: The feed xml root element.
+		:returns: The feed root element.
+		'''
+		return feed
+
+
+	def extend_atom(self, feed, doc=None):
+		'''Create an ATOM feed xml structure containing all previously set
+		fields.
+
+		:param feed: The feed xml root element.
+		:returns: The feed root element.
+		'''
+		return feed, doc
+
+
+class BaseEntryExtension(BaseExtension):
+	'''Basic FeedEntry extension.
+	'''

feedgen/ext/podcast.py

@@ -14,12 +14,11 @@ from lxml import etree
 from datetime import datetime
 import dateutil.parser
 import dateutil.tz
-from feedgen.feed import FeedGenerator
+from feedgen.ext.base import BaseExtension
-from feedgen.podcast_entry import PodcastEntry
 from feedgen.util import ensure_format
 
 
-class PodcastGenerator(FeedGenerator):
+class PodcastExtension(BaseExtension):
 	'''FeedGenerator extension for podcasts.
 	'''
 
@@ -40,21 +39,18 @@ class PodcastGenerator(FeedGenerator):
 
 
 
-	def __create_podcast(self):
+	def extend_rss(self, rss_feed):
 		'''Create an RSS feed xml structure containing all previously set fields.
 
 		:returns: Tuple containing the feed root element and the element tree.
 		'''
-		rss_feed, _ = super(PodcastGenerator,self)._create_rss()
 		ITUNES_NS = 'http://www.itunes.com/dtds/podcast-1.0.dtd'
 		# Replace the root element to add the itunes namespace
-		feed = etree.Element('rss', version='2.0',
+		nsmap = rss_feed.nsmap
-				nsmap={
+		nsmap['itunes'] = ITUNES_NS
-					'atom'  :'http://www.w3.org/2005/Atom', 
+		feed = etree.Element('rss', version='2.0', nsmap=nsmap )
-					'itunes':ITUNES_NS} )
 		feed[:] = rss_feed[:]
 		channel = feed[0]
-		doc     = etree.ElementTree(feed)
 
 		if self.__itunes_author:
 			author = etree.SubElement(channel, '{%s}author' % ITUNES_NS)
@@ -102,28 +98,7 @@ class PodcastGenerator(FeedGenerator):
 			summary = etree.SubElement(channel, '{%s}summary' % ITUNES_NS)
 			summary.text = self.__itunes_summary
 
-		return feed, doc
+		return feed
-
-
-	def podcast_str(self, pretty=False):
-		'''Generates an RSS feed and returns the feed XML as string.
-		
-		:param pretty: If the feed should be split into multiple lines and
-			properly indented.
-		:returns: String representation of the RSS feed.
-		'''
-		feed, doc = self.__create_podcast()
-		return etree.tostring(feed, pretty_print=pretty)
-
-
-	def podcast_file(self, filename):
-		'''Generates an RSS feed and write the resulting XML to a file.
-		
-		:param filename: Name of file to write.
-		'''
-		feed, doc = self.__create_podcast()
-		with open(filename, 'w') as f:
-			doc.write(f)
 
 
 	def itunes_author(self, itunes_author=None):
@@ -313,20 +288,6 @@ class PodcastGenerator(FeedGenerator):
 		return self.__itunes_summary
 
 
-	def add_entry(self, podcastEntry=None):
-		'''This method will add a new entry to the podcast. If the podcastEntry
-		argument is omittet a new PodcstEntry object is created automatically.
-		This is the prefered way to add new entries to a feed.
-
-		:param podcastEntry: PodcastEntry object to add.
-		:returns: PodcastEntry object created or passed to this function.
-		'''
-		if podcastEntry is None:
-			podcastEntry = PodcastEntry()
-		super(PodcastGenerator, self).add_entry( podcastEntry )
-		return podcastEntry
-
-
 	_itunes_categories = {
 			'Arts': [ 'Design', 'Fashion & Beauty', 'Food', 'Literature',
 				'Performing Arts', 'Visual Arts' ],

feedgen/ext/podcast_entry.py

@@ -14,11 +14,11 @@ from lxml import etree
 from datetime import datetime
 import dateutil.parser
 import dateutil.tz
-from feedgen.entry import FeedEntry
+from feedgen.ext.base import BaseExtension
 from feedgen.util import ensure_format
 
 
-class PodcastEntry(FeedEntry):
+class PodcastEntryExtension(BaseExtension):
 	'''FeedEntry extension for podcasts.
 	'''
 
@@ -36,13 +36,11 @@ class PodcastEntry(FeedEntry):
 	__itunes_summary             = None
 
 
-	def rss_entry(self, feed):
+	def extend_rss(self, entry):
-		'''Insert an RSS item into a existing XML structure. Normally you
+		'''Add additional fields to an RSS item.
-		would pass the channel node of an RSS feed XML to this function.
 
-		:param feed: The XML element to use as parent node for the item.
+		:param feed: The RSS item XML element to use.
 		'''
-		entry = super(PodcastEntry,self).rss_entry(feed)
 		ITUNES_NS = 'http://www.itunes.com/dtds/podcast-1.0.dtd'
 
 		if self.__itunes_author:

feedgen/feed.py

@@ -69,9 +69,12 @@ class FeedGenerator(object):
 	__rss_ttl            = None
 	__rss_webMaster      = None
 
+	# Extension list:
+	__extensions = {}
 
 
-	def _create_atom(self):
+
+	def _create_atom(self, extensions=True):
 		'''Create a ATOM feed xml structure containing all previously set fields.
 
 		:returns: Tuple containing the feed root element and the element tree.
@@ -81,7 +84,6 @@ class FeedGenerator(object):
 			feed.attrib['{http://www.w3.org/XML/1998/namespace}lang'] = \
 					self.__atom_feed_xml_lang
 
-		doc     = etree.ElementTree(feed)
 		if not ( self.__atom_id and self.__atom_title and self.__atom_updated ):
 			raise ValueError('Required fields not set')
 		id      = etree.SubElement(feed, 'id')
@@ -165,41 +167,50 @@ class FeedGenerator(object):
 			subtitle = etree.SubElement(feed, 'subtitle')
 			subtitle.text = self.__atom_subtitle
 
+		if extensions:
+			for ext in self.__extensions.values() or []:
+				if ext.get('atom'):
+					feed = ext['inst'].extend_atom(feed)
+
 		for entry in self.__feed_entries:
 			entry.atom_entry(feed)
 
+		doc = etree.ElementTree(feed)
 		return feed, doc
 
 
-	def atom_str(self, pretty=False):
+	def atom_str(self, pretty=False, extensions=True):
 		'''Generates an ATOM feed and returns the feed XML as string.
 		
 		:param pretty: If the feed should be split into multiple lines and
 			properly indented.
+		:param extensions: Enable or disable the loaded extensions for the xml
+			generation (default: enabled).
 		:returns: String representation of the ATOM feed.
 		'''
-		feed, doc = self._create_atom()
+		feed, doc = self._create_atom(extensions=extensions)
 		return etree.tostring(feed, pretty_print=pretty)
 
 
-	def atom_file(self, filename):
+	def atom_file(self, filename, extensions=True):
 		'''Generates an ATOM feed and write the resulting XML to a file.
 		
 		:param filename: Name of file to write.
+		:param extensions: Enable or disable the loaded extensions for the xml
+			generation (default: enabled).
 		'''
-		feed, doc = self._create_atom()
+		feed, doc = self._create_atom(extensions=extensions)
 		with open(filename, 'w') as f:
 			doc.write(f)
 
 
-	def _create_rss(self):
+	def _create_rss(self, extensions=True):
 		'''Create an RSS feed xml structure containing all previously set fields.
 
 		:returns: Tuple containing the feed root element and the element tree.
 		'''
 		feed    = etree.Element('rss', version='2.0',
 				nsmap={'atom':  'http://www.w3.org/2005/Atom'} )
-		doc     = etree.ElementTree(feed)
 		channel = etree.SubElement(feed, 'channel')
 		if not ( self.__rss_title and self.__rss_link and self.__rss_description ):
 			raise ValueError('Required fields not set')
@@ -306,29 +317,39 @@ class FeedGenerator(object):
 			webMaster = etree.SubElement(channel, 'webMaster')
 			webMaster.text = self.__rss_webMaster
 
+		if extensions:
+			for ext in self.__extensions.values() or []:
+				if ext.get('rss'):
+					feed = ext['inst'].extend_rss(feed)
+
 		for entry in self.__feed_entries:
 			entry.rss_entry(channel)
 
+		doc = etree.ElementTree(feed)
 		return feed, doc
 
 
-	def rss_str(self, pretty=False):
+	def rss_str(self, pretty=False, extensions=True):
 		'''Generates an RSS feed and returns the feed XML as string.
 		
 		:param pretty: If the feed should be split into multiple lines and
 			properly indented.
+		:param extensions: Enable or disable the loaded extensions for the xml
+			generation (default: enabled).
 		:returns: String representation of the RSS feed.
 		'''
-		feed, doc = self._create_rss()
+		feed, doc = self._create_rss(extensions=extensions)
 		return etree.tostring(feed, pretty_print=pretty)
 
 
-	def rss_file(self, filename):
+	def rss_file(self, filename, extensions=True):
 		'''Generates an RSS feed and write the resulting XML to a file.
 		
 		:param filename: Name of file to write.
+		:param extensions: Enable or disable the loaded extensions for the xml
+			generation (default: enabled).
 		'''
-		feed, doc = self._create_rss()
+		feed, doc = self._create_rss(extensions=extensions)
 		with open(filename, 'w') as f:
 			doc.write(f)
 
@@ -916,6 +937,14 @@ class FeedGenerator(object):
 		'''
 		if feedEntry is None:
 			feedEntry = FeedEntry()
+
+		# Try to load extensions:
+		for extname,ext in self.__extensions.iteritems():
+			try:
+				feedEntry.load_extension( extname, ext['atom'], ext['rss'] )
+			except ImportError:
+				pass
+
 		self.__feed_entries.append( feedEntry )
 		return feedEntry
 
@@ -942,6 +971,16 @@ class FeedGenerator(object):
 				entry = [entry]
 			if replace:
 				self.__feed_entries = []
+
+
+			# Try to load extensions:
+			for e in entry:
+				for extname,ext in self.__extensions.iteritems():
+					try:
+						e.load_extension( extname, ext['atom'], ext['rss'] )
+					except ImportError:
+						pass
+
 			self.__feed_entries += entry
 		return self.__feed_entries
 
@@ -969,3 +1008,33 @@ class FeedGenerator(object):
 		remove_entry.
 		'''
 		self.remove_entry(item)
+
+	
+	def load_extension(self, name, atom=True, rss=True):
+		'''Load a specific extension by name.
+
+		:param name: Name of the extension to load.
+		:param atom: If the extension should be used for ATOM feeds.
+		:param rss: If the extension should be used for RSS feeds.
+		'''
+		# Check loaded extensions
+		if not isinstance(self.__extensions, dict):
+			self.__extensions = {}
+		if name in self.__extensions.keys():
+			raise ImportError('Extension already loaded')
+
+		# Load extension
+		extname = name[0].upper() + name[1:] + 'Extension'
+		supmod = __import__('feedgen.ext.%s' % name)
+		extmod = getattr(supmod.ext, name)
+		ext    = getattr(extmod, extname)
+		extinst = ext()
+		setattr(self, name, extinst)
+		self.__extensions[name] = {'inst':extinst,'atom':atom,'rss':rss}
+
+		# Try to load the extension for already existing entries:
+		for entry in self.__feed_entries:
+			try:
+				entry.load_extension( name, atom, rss )
+			except ImportError:
+				pass