=============
Feedgenerator
=============

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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.

It is licensed under the terms of both, the FreeBSD license and the LGPLv3+.
Choose the one which is more convenient for you. For more details have a look
at license.bsd and license.lgpl.

More details about the project:

- Repository:            https://github.com/lkiesow/python-feedgen
- Documentation:         http://lkiesow.github.io/python-feedgen/
- Python Package Index:  https://pypi.python.org/pypi/feedgen/


------------
Installation
------------

**Prebuild packages**

If you are running Fedora Linux, RedHat Enterprise Linux, CentOS or Scientific
Linux you can use the RPM Copr repostiory:

http://copr.fedoraproject.org/coprs/lkiesow/python-feedgen/

Simply enable the repository and run::

    $ yum install python-feedgen

or for the Python 3 package::

    $ yum install python3-feedgen


**Using pip**

You can also use pip to install the feedgen module. Simply run::

    $ pip install feedgen


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

To create a feed simply instanciate 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 Doe', '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` control if the extension is used for ATOM and
RSS feeds, respectively. The default value for both parameters is `true`
meaning the extension is 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')
    ...
    >>> fe = fg.add_entry()
    >>> fe.id('http://lernfunk.de/media/654321/1/file.mp3')
    >>> fe.title('The First Episode')
    >>> fe.description('Enjoy our first episode.')
    >>> fe.enclosure('http://lernfunk.de/media/654321/1/file.mp3', 0, 'audio/mpeg')
    ...
    >>> 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.

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`.

**Custom Extensions**

If you want to load custom extension which are not part of the feedgen Python
package, you can use the method `register_extension` instead. You can directly
pass the classes for the feed and the entry extension to this method meaning
that you can define them everywhere.


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

You can test the module by simply executing::

    $ python -m feedgen

If you want to have a look at the code for this test to have a working code
example for a whole feed generation process, you can find it in the
`__main__.py <https://github.com/lkiesow/python-feedgen/blob/master/feedgen/__main__.py>`_.