OVPNconsole/Django-1.0/docs/ref/contrib/sitemaps.txt

.. _ref-contrib-sitemaps:

=====================
The sitemap framework
=====================

.. module:: django.contrib.sitemaps
   :synopsis: A framework for generating Google sitemap XML files.

Django comes with a high-level sitemap-generating framework that makes
creating sitemap_ XML files easy.

.. _sitemap: http://www.sitemaps.org/

Overview
========

A sitemap is an XML file on your Web site that tells search-engine indexers how
frequently your pages change and how "important" certain pages are in relation
to other pages on your site. This information helps search engines index your
site.

The Django sitemap framework automates the creation of this XML file by letting
you express this information in Python code.

It works much like Django's :ref:`syndication framework
<ref-contrib-syndication>`. To create a sitemap, just write a
:class:`~django.contrib.sitemaps.Sitemap` class and point to it in your
:ref:`URLconf <topics-http-urls>`.

Installation
============

To install the sitemap app, follow these steps:

    1. Add ``'django.contrib.sitemaps'`` to your :setting:`INSTALLED_APPS`
       setting.
       
    2. Make sure ``'django.template.loaders.app_directories.load_template_source'``
       is in your :setting:`TEMPLATE_LOADERS` setting. It's in there by default,
       so you'll only need to change this if you've changed that setting.

    3. Make sure you've installed the 
       :mod:`sites framework <django.contrib.sites>`.

(Note: The sitemap application doesn't install any database tables. The only
reason it needs to go into :setting:`INSTALLED_APPS` is so that the
:func:`~django.template.loaders.app_directories.load_template_source` template
loader can find the default templates.)

Initialization
==============

To activate sitemap generation on your Django site, add this line to your
:ref:`URLconf <topics-http-urls>`::

   (r'^sitemap.xml$', 'django.contrib.sitemaps.views.sitemap', {'sitemaps': sitemaps})

This tells Django to build a sitemap when a client accesses :file:`/sitemap.xml`.

The name of the sitemap file is not important, but the location is. Search
engines will only index links in your sitemap for the current URL level and
below. For instance, if :file:`sitemap.xml` lives in your root directory, it may
reference any URL in your site. However, if your sitemap lives at
:file:`/content/sitemap.xml`, it may only reference URLs that begin with
:file:`/content/`.

The sitemap view takes an extra, required argument: ``{'sitemaps': sitemaps}``.
``sitemaps`` should be a dictionary that maps a short section label (e.g.,
``blog`` or ``news``) to its :class:`~django.contrib.sitemaps.Sitemap` class
(e.g., ``BlogSitemap`` or ``NewsSitemap``). It may also map to an *instance* of
a :class:`~django.contrib.sitemaps.Sitemap` class (e.g.,
``BlogSitemap(some_var)``).

Sitemap classes
===============

A :class:`~django.contrib.sitemaps.Sitemap` class is a simple Python
class that represents a "section" of entries in your sitemap. For example,
one :class:`~django.contrib.sitemaps.Sitemap` class could represent
all the entries of your weblog, while another could represent all of the
events in your events calendar.

In the simplest case, all these sections get lumped together into one
:file:`sitemap.xml`, but it's also possible to use the framework to generate a
sitemap index that references individual sitemap files, one per section. (See
`Creating a sitemap index`_ below.)

:class:`~django.contrib.sitemaps.Sitemap` classes must subclass
``django.contrib.sitemaps.Sitemap``. They can live anywhere in your codebase.

A simple example
================

Let's assume you have a blog system, with an ``Entry`` model, and you want your
sitemap to include all the links to your individual blog entries. Here's how
your sitemap class might look::

    from django.contrib.sitemaps import Sitemap
    from mysite.blog.models import Entry

    class BlogSitemap(Sitemap):
        changefreq = "never"
        priority = 0.5

        def items(self):
            return Entry.objects.filter(is_draft=False)

        def lastmod(self, obj):
            return obj.pub_date

Note:

    * :attr:`~Sitemap.changefreq` and :attr:`~Sitemap.priority` are class
      attributes corresponding to ``<changefreq>`` and ``<priority>`` elements,
      respectively. They can be made callable as functions, as
      :attr:`~Sitemap.lastmod` was in the example.
    * :attr:`~Sitemap.items()` is simply a method that returns a list of
      objects. The objects returned will get passed to any callable methods
      corresponding to a sitemap property (:attr:`~Sitemap.location`,
      :attr:`~Sitemap.lastmod`, :attr:`~Sitemap.changefreq`, and
      :attr:`~Sitemap.priority`).
    * :attr:`~Sitemap.lastmod` should return a Python ``datetime`` object.
    * There is no :attr:`~Sitemap.location` method in this example, but you
      can provide it in order to specify the URL for your object. By default,
      :attr:`~Sitemap.location()` calls ``get_absolute_url()`` on each object
      and returns the result.

Sitemap class reference
=======================

.. class:: Sitemap

    A ``Sitemap`` class can define the following methods/attributes:

    .. attribute:: Sitemap.items

        **Required.** A method that returns a list of objects. The framework
        doesn't care what *type* of objects they are; all that matters is that
        these objects get passed to the :attr:`~Sitemap.location()`,
        :attr:`~Sitemap.lastmod()`, :attr:`~Sitemap.changefreq()` and
        :attr:`~Sitemap.priority()` methods.

    .. attribute:: Sitemap.location

        **Optional.** Either a method or attribute.

        If it's a method, it should return the absolute URL for a given object as
        returned by :attr:`~Sitemap.items()`.

        If it's an attribute, its value should be a string representing an absolute URL
        to use for *every* object returned by :attr:`~Sitemap.items()`.

        In both cases, "absolute URL" means a URL that doesn't include the protocol or
        domain. Examples:

            * Good: :file:`'/foo/bar/'`
            * Bad: :file:`'example.com/foo/bar/'`
            * Bad: :file:`'http://example.com/foo/bar/'`

        If :attr:`~Sitemap.location` isn't provided, the framework will call the
        ``get_absolute_url()`` method on each object as returned by
        :attr:`~Sitemap.items()`.

    .. attribute:: Sitemap.lastmod

        **Optional.** Either a method or attribute.

        If it's a method, it should take one argument -- an object as returned by
        :attr:`~Sitemap.items()` -- and return that object's last-modified date/time, as a Python
        ``datetime.datetime`` object.

        If it's an attribute, its value should be a Python ``datetime.datetime`` object
        representing the last-modified date/time for *every* object returned by
        :attr:`~Sitemap.items()`.

    .. attribute:: Sitemap.changefreq

        **Optional.** Either a method or attribute.

        If it's a method, it should take one argument -- an object as returned by
        :attr:`~Sitemap.items()` -- and return that object's change frequency, as a Python string.

        If it's an attribute, its value should be a string representing the change
        frequency of *every* object returned by :attr:`~Sitemap.items()`.

        Possible values for :attr:`~Sitemap.changefreq`, whether you use a method or attribute, are:

            * ``'always'``
            * ``'hourly'``
            * ``'daily'``
            * ``'weekly'``
            * ``'monthly'``
            * ``'yearly'``
            * ``'never'``

    .. method:: Sitemap.priority

        **Optional.** Either a method or attribute.

        If it's a method, it should take one argument -- an object as returned by
        :attr:`~Sitemap.items()` -- and return that object's priority, as either a string or float.

        If it's an attribute, its value should be either a string or float representing
        the priority of *every* object returned by :attr:`~Sitemap.items()`.

        Example values for :attr:`~Sitemap.priority`: ``0.4``, ``1.0``. The default priority of a
        page is ``0.5``. See the `sitemaps.org documentation`_ for more.

        .. _sitemaps.org documentation: http://www.sitemaps.org/protocol.html#prioritydef

Shortcuts
=========

The sitemap framework provides a couple convenience classes for common cases:

.. class:: FlatPageSitemap

    The :class:`django.contrib.sitemaps.FlatPageSitemap` class looks at all
    :mod:`flatpages <django.contrib.flatpages>` defined for the current
    :setting:`SITE_ID` (see the
    :mod:`sites documentation <django.contrib.sites>`) and
    creates an entry in the sitemap. These entries include only the
    :attr:`~Sitemap.location` attribute -- not :attr:`~Sitemap.lastmod`,
    :attr:`~Sitemap.changefreq` or :attr:`~Sitemap.priority`.

.. class:: GenericSitemap

    The :class:`django.contrib.sitemaps.GenericSitemap` class works with any
    :ref:`generic views <ref-generic-views>` you already have.
    To use it, create an instance, passing in the same :data:`info_dict` you pass to
    the generic views. The only requirement is that the dictionary have a
    :data:`queryset` entry. It may also have a :data:`date_field` entry that specifies a
    date field for objects retrieved from the :data:`queryset`. This will be used for
    the :attr:`~Sitemap.lastmod` attribute in the generated sitemap. You may
    also pass :attr:`~Sitemap.priority` and :attr:`~Sitemap.changefreq`
    keyword arguments to the :class:`~django.contrib.sitemaps.GenericSitemap`
    constructor to specify these attributes for all URLs.

Example
-------

Here's an example of a :ref:`URLconf <topics-http-urls>` using both::

    from django.conf.urls.defaults import *
    from django.contrib.sitemaps import FlatPageSitemap, GenericSitemap
    from mysite.blog.models import Entry

    info_dict = {
        'queryset': Entry.objects.all(),
        'date_field': 'pub_date',
    }

    sitemaps = {
        'flatpages': FlatPageSitemap,
        'blog': GenericSitemap(info_dict, priority=0.6),
    }

    urlpatterns = patterns('',
        # some generic view using info_dict
        # ...

        # the sitemap
        (r'^sitemap.xml$', 'django.contrib.sitemaps.views.sitemap', {'sitemaps': sitemaps})
    )

.. _URLconf: ../url_dispatch/

Creating a sitemap index
========================

The sitemap framework also has the ability to create a sitemap index that
references individual sitemap files, one per each section defined in your
:data:`sitemaps` dictionary. The only differences in usage are:

    * You use two views in your URLconf: :func:`django.contrib.sitemaps.views.index`
      and :func:`django.contrib.sitemaps.views.sitemap`.
    * The :func:`django.contrib.sitemaps.views.sitemap` view should take a
      :data:`section` keyword argument.

Here is what the relevant URLconf lines would look like for the example above::

   (r'^sitemap.xml$', 'django.contrib.sitemaps.views.index', {'sitemaps': sitemaps})
   (r'^sitemap-(?P<section>.+)\.xml$', 'django.contrib.sitemaps.views.sitemap', {'sitemaps': sitemaps})

This will automatically generate a :file:`sitemap.xml` file that references both
:file:`sitemap-flatpages.xml` and :file:`sitemap-blog.xml`. The
:class:`~django.contrib.sitemaps.Sitemap` classes and the :data:`sitemaps` dict
don't change at all.

If one of your sitemaps is going to have more than 50,000 URLs you should 
create an index file. Your sitemap will be paginated and the index will 
reflect that.

Pinging Google
==============

You may want to "ping" Google when your sitemap changes, to let it know to
reindex your site. The sitemaps framework provides a function to do just 
that: :func:`django.contrib.sitemaps.ping_google()`.

.. function:: ping_google

    :func:`ping_google` takes an optional argument, :data:`sitemap_url`,
    which should be the absolute URL of your site's sitemap (e.g.,
    :file:`'/sitemap.xml'`). If this argument isn't provided,
    :func:`ping_google` will attempt to figure out your
    sitemap by performing a reverse looking in your URLconf.

    :func:`ping_google` raises the exception
    :exc:`django.contrib.sitemaps.SitemapNotFound` if it cannot determine your
    sitemap URL.

.. admonition:: Register with Google first!

    The :func:`ping_google` command only works if you have registered your
    site with `Google Webmaster Tools`_.
        
.. _`Google Webmaster Tools`: http://www.google.com/webmasters/tools/
        
One useful way to call :func:`ping_google` is from a model's ``save()``
method::

   from django.contrib.sitemaps import ping_google
  
    class Entry(models.Model):
        # ...
        def save(self, force_insert=False, force_update=False):
            super(Entry, self).save(force_insert, force_update)
            try:
                ping_google()
            except Exception:
                # Bare 'except' because we could get a variety
                # of HTTP-related exceptions.
                pass

A more efficient solution, however, would be to call :func:`ping_google` from a
cron script, or some other scheduled task. The function makes an HTTP request
to Google's servers, so you may not want to introduce that network overhead
each time you call ``save()``.

Pinging Google via `manage.py`
------------------------------

.. versionadded:: 1.0

Once the sitemaps application is added to your project, you may also
ping the Google server's through the command line manage.py interface::

    python manage.py ping_google [/sitemap.xml]