API Documentation
*****************


feedgen
=======

This module can be used to generate web feeds in both ATOM and RSS
format. It has support for extensions. Included is for example an
extension to produce Podcasts.

copyright:
   2013 by Lars Kiesow

license:
   FreeBSD and LGPL, see license.* for more details.


Create a Feed
-------------

To create a feed simply instantiate the FeedGenerator class and insert
some data:

   >>> from feedgen.feed import FeedGenerator
   >>> fg = FeedGenerator()
   >>> fg.id('http://lernfunk.de/media/654321')
   >>> fg.title('Some Testfeed')
   >>> fg.author( {'name':'John Doe','email':'john@example.de'} )
   >>> fg.link( href='http://example.com', rel='alternate' )
   >>> fg.logo('http://ex.com/logo.jpg')
   >>> fg.subtitle('This is a cool feed!')
   >>> fg.link( href='http://larskiesow.de/test.atom', rel='self' )
   >>> fg.language('en')

Note that for the methods which set fields that can occur more than
once in a feed you can use all of the following ways to provide data:

* Provide the data for that element as keyword arguments

* Provide the data for that element as dictionary

* Provide a list of dictionaries with the data for several elements

Example:

   >>> fg.contributor(name='John Doe', email='jdoe@example.com' )
   >>> fg.contributor({'name':'John Doe', 'email':'jdoe@example.com'})
   >>> fg.contributor([{'name':'John', 'email':'jdoe@example.com'}, …])


Generate the Feed
-----------------

After that you can generate both RSS or ATOM by calling the respective
method:

   >>> atomfeed = fg.atom_str(pretty=True) # Get the ATOM feed as string
   >>> rssfeed  = fg.rss_str(pretty=True) # Get the RSS feed as string
   >>> fg.atom_file('atom.xml') # Write the ATOM feed to a file
   >>> fg.rss_file('rss.xml') # Write the RSS feed to a file


Add Feed Entries
----------------

To add entries (items) to a feed you need to create new FeedEntry
objects and append them to the list of entries in the FeedGenerator.
The most convenient way to go is to use the FeedGenerator itself for
the instantiation of the FeedEntry object:

   >>> fe = fg.add_entry()
   >>> fe.id('http://lernfunk.de/media/654321/1')
   >>> fe.title('The First Episode')

The FeedGenerators method add_entry(...) without argument provides
will automatically generate a new FeedEntry object, append it to the
feeds internal list of entries and return it, so that additional data
can be added.


Extensions
----------

The FeedGenerator supports extension to include additional data into
the XML structure of the feeds. Extensions can be loaded like this:

   >>> fg.load_extension('someext', atom=True, rss=True)

This will try to load the extension “someext” from the file
*ext/someext.py*. It is required that *someext.py* contains a class
named “SomextExtension” which is required to have at least the two
methods *extend_rss(...)* and *extend_atom(...)*. Although not
required, it is strongly suggested to use BaseExtension from
*ext/base.py* as superclass.

*load_extension('someext', ...)* will also try to load a class named
“SomextEntryExtension” for every entry of the feed. This class can be
located either in the same file as SomextExtension or in
*ext/someext_entry.py* which is suggested especially for large
extensions.

The parameters *atom* and *rss* tell the FeedGenerator if the
extensions should only be used for either ATOM or RSS feeds. The
default value for both parameters is true which means that the
extension would be used for both kinds of feeds.

**Example: Producing a Podcast**

One extension already provided is the podcast extension. A podcast is
an RSS feed with some additional elements for ITunes.

To produce a podcast simply load the *podcast* extension:

   >>> from feedgen.feed import FeedGenerator
   >>> fg = FeedGenerator()
   >>> fg.load_extension('podcast')
   ...
   >>> fg.podcast.itunes_category('Technology', 'Podcasting')
   ...
   >>> fg.rss_str(pretty=True)
   >>> fg.rss_file('podcast.xml')

Of cause the extension has to be loaded for the FeedEntry objects as
well but this is done automatically by the FeedGenerator for every
feed entry if the extension is loaded for the whole feed. You can,
however, load an extension for a specific FeedEntry by calling
*load_extension(...)* on that entry. But this is a rather uncommon
use.

Of cause you can still produce a normal ATOM or RSS feed, even if you
have loaded some plugins by temporary disabling them during the feed
generation. This can be done by calling the generating method with the
keyword argument *extensions* set to *False*.


Testing the Generator
---------------------

You can test the module by simply executing:

   $ python -m feedgen

Contents:

* feedgen.feed

* feedgen.entry

* feedgen.util

* feedgen.ext.base

* feedgen.ext.dc

* feedgen.ext.podcast

* feedgen.ext.podcast_entry

* feedgen.ext.torrent
