pelican/docs/plugins.rst

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.. _plugins:
Plugins
#######
Since version 3.0, Pelican manages plugins. Plugins are a way to add features
to Pelican without having to directly hack Pelican code.
Pelican is shipped with a set of core plugins, but you can easily implement
your own (and this page describes how).
How to use plugins
==================
To load plugins, you have to specify them in your settings file. You have two
ways to do so.
Either by specifying strings with the path to the callables::
PLUGINS = ['pelican.plugins.gravatar',]
Or by importing them and adding them to the list::
from pelican.plugins import gravatar
PLUGINS = [gravatar, ]
If your plugins are not in an importable path, you can specify a ``PLUGIN_PATH``
in the settings::
PLUGIN_PATH = "plugins"
PLUGINS = ["list", "of", "plugins"]
How to create plugins
=====================
Plugins are based on the concept of signals. Pelican sends signals, and plugins
subscribe to those signals. The list of signals are defined in a following
section.
The only rule to follow for plugins is to define a ``register`` callable, in
which you map the signals to your plugin logic. Let's take a simple example::
from pelican import signals
def test(sender):
print "%s initialized !!" % sender
def register():
signals.initialized.connect(test)
List of signals
===============
Here is the list of currently implemented signals:
========================= ============================ ===========================================================================
Signal Arguments Description
========================= ============================ ===========================================================================
initialized pelican object
finalized pelican object invoked after all the generators are executed and just before pelican exits
usefull for custom post processing actions, such as:
- minifying js/css assets.
- notify/ping search engines with an updated sitemap.
article_generate_context article_generator, metadata
article_generator_init article_generator invoked in the ArticlesGenerator.__init__
get_generators generators invoked in Pelican.get_generator_classes,
can return a Generator, or several
generator in a tuple or in a list.
pages_generate_context pages_generator, metadata
pages_generator_init pages_generator invoked in the PagesGenerator.__init__
========================= ============================ ===========================================================================
The list is currently small, don't hesitate to add signals and make a pull
request if you need them!
List of plugins
===============
Not all the list are described here, but a few of them have been extracted from
the Pelican core and provided in ``pelican.plugins``. They are described here:
Tag cloud
---------
Translation
-----------
GitHub activity
---------------
This plugin makes use of the ``feedparser`` library that you'll need to
install.
Set the ``GITHUB_ACTIVITY_FEED`` parameter to your GitHub activity feed.
For example, my setting would look like::
GITHUB_ACTIVITY_FEED = 'https://github.com/kpanic.atom'
On the templates side, you just have to iterate over the ``github_activity``
variable, as in the example::
{% if GITHUB_ACTIVITY_FEED %}
<div class="social">
<h2>Github Activity</h2>
<ul>
{% for entry in github_activity %}
<li><b>{{ entry[0] }}</b><br /> {{ entry[1] }}</li>
{% endfor %}
</ul>
</div><!-- /.github_activity -->
{% endif %}
``github_activity`` is a list of lists. The first element is the title
and the second element is the raw HTML from GitHub.
Sitemap
-------
The plugin generates a sitemap of the blog.
It can generates plain text sitemaps or XML sitemaps.
Configuration
"""""""""""""
You can use the setting ``SITEMAP`` variable to configure the behavior of the
plugin.
The ``SITEMAP`` variable must be a Python dictionary, it can contain tree keys:
- ``format``, which set the output format of the plugin (``xml`` or ``txt``)
- ``priorities``, which is a dictionary with three keys:
- ``articles``, the priority for the URLs of the articles and their
translations
- ``pages``, the priority for the URLs of the static pages
- ``indexes``, the priority for the URLs of the index pages, such as tags,
author pages, categories indexes, archives, etc...
All the values of this dictionary must be decimal numbers between ``0`` and ``1``.
- ``changefreqs``, which is a dictionary with three items:
- ``articles``, the update frequency of the articles
- ``pages``, the update frequency of the pages
- ``indexes``, the update frequency of the index pages
An valid value is ``always``, ``hourly``, ``daily``, ``weekly``, ``monthly``,
``yearly`` or ``never``.
If a key is missing or a value is incorrect, it will be replaced with the
default value.
The sitemap is saved in ``<output_path>/sitemap.<format>``.
.. note::
``priorities`` and ``changefreqs`` are informations for search engines.
They are only used in the XML sitemaps.
For more information: <http://www.sitemaps.org/protocol.html#xmlTagDefinitions>
Example
"""""""
Here is an example of configuration (it's also the default settings):
.. code-block:: python
PLUGINS=['pelican.plugins.sitemap',]
SITEMAP = {
'format': 'xml',
'priorities': {
'articles': 0.5,
'indexes': 0.5,
'pages': 0.5
},
'changefreqs': {
'articles': 'monthly',
'indexes': 'daily',
'pages': 'monthly'
}
}