=================
The flatpages app
=================
.. module:: django.contrib.flatpages
:synopsis: A framework for managing simple ?flat? HTML content in a database.
Django comes with an optional "flatpages" application. It lets you store simple
"flat" HTML content in a database and handles the management for you via
Django's admin interface and a Python API.
A flatpage is a simple object with a URL, title and content. Use it for
one-off, special-case pages, such as "About" or "Privacy Policy" pages, that
you want to store in a database but for which you don't want to develop a
custom Django application.
A flatpage can use a custom template or a default, systemwide flatpage
template. It can be associated with one, or multiple, sites.
The content field may optionally be left blank if you prefer to put your
content in a custom template.
Here are some examples of flatpages on Django-powered sites:
* http://www.lawrence.com/about/contact/
* http://www2.ljworld.com/site/rules/
Installation
============
To install the flatpages app, follow these steps:
1. Install the :mod:`sites framework <django.contrib.sites>` by adding
``'django.contrib.sites'`` to your :setting:`INSTALLED_APPS` setting,
if it's not already in there.
Also make sure you've correctly set :setting:`SITE_ID` to the ID of the
site the settings file represents. This will usually be ``1`` (i.e.
``SITE_ID = 1``, but if you're using the sites framework to manage
multiple sites, it could be the ID of a different site.
2. Add ``'django.contrib.flatpages'`` to your :setting:`INSTALLED_APPS`
setting.
3. Add ``'django.contrib.flatpages.middleware.FlatpageFallbackMiddleware'``
to your :setting:`MIDDLEWARE_CLASSES` setting.
4. Run the command :djadmin:`manage.py syncdb <syncdb>`.
.. currentmodule:: django.contrib.flatpages.middleware
How it works
============
``manage.py syncdb`` creates two tables in your database: ``django_flatpage``
and ``django_flatpage_sites``. ``django_flatpage`` is a simple lookup table
that simply maps a URL to a title and bunch of text content.
``django_flatpage_sites`` associates a flatpage with a site.
The :class:`~django.contrib.flatpages.middleware.FlatpageFallbackMiddleware`
does all of the work.
.. class:: FlatpageFallbackMiddleware
Each time any Django application raises a 404 error, this middleware
checks the flatpages database for the requested URL as a last resort.
Specifically, it checks for a flatpage with the given URL with a site ID
that corresponds to the :setting:`SITE_ID` setting.
If it finds a match, it follows this algorithm:
* If the flatpage has a custom template, it loads that template.
Otherwise, it loads the template :file:`flatpages/default.html`.
* It passes that template a single context variable, ``flatpage``,
which is the flatpage object. It uses
:class:`~django.template.RequestContext` in rendering the
template.
If it doesn't find a match, the request continues to be processed as usual.
The middleware only gets activated for 404s -- not for 500s or responses
of any other status code.
.. admonition:: Flatpages will not apply view middleware
Because the ``FlatpageFallbackMiddleware`` is applied only after
URL resolution has failed and produced a 404, the response it
returns will not apply any :ref:`view middleware <view-middleware>`
methods. Only requests which are successfully routed to a view via
normal URL resolution apply view middleware.
Note that the order of :setting:`MIDDLEWARE_CLASSES` matters. Generally, you can
put :class:`~django.contrib.flatpages.middleware.FlatpageFallbackMiddleware` at
the end of the list, because it's a last resort.
For more on middleware, read the :doc:`middleware docs
</topics/http/middleware>`.
.. admonition:: Ensure that your 404 template works
Note that the
:class:`~django.contrib.flatpages.middleware.FlatpageFallbackMiddleware`
only steps in once another view has successfully produced a 404 response.
If another view or middleware class attempts to produce a 404 but ends up
raising an exception instead (such as a ``TemplateDoesNotExist``
exception if your site does not have an appropriate template to
use for HTTP 404 responses), the response will become an HTTP 500
("Internal Server Error") and the
:class:`~django.contrib.flatpages.middleware.FlatpageFallbackMiddleware`
will not attempt to serve a flat page.
.. currentmodule:: django.contrib.flatpages.models
How to add, change and delete flatpages
=======================================
Via the admin interface
-----------------------
If you've activated the automatic Django admin interface, you should see a
"Flatpages" section on the admin index page. Edit flatpages as you edit any
other object in the system.
Via the Python API
------------------
.. class:: FlatPage
Flatpages are represented by a standard
:doc:`Django model </topics/db/models>`,
which lives in `django/contrib/flatpages/models.py`_. You can access
flatpage objects via the :doc:`Django database API </topics/db/queries>`.
.. _django/contrib/flatpages/models.py: http://code.djangoproject.com/browser/django/trunk/django/contrib/flatpages/models.py
.. currentmodule:: django.contrib.flatpages
Flatpage templates
==================
By default, flatpages are rendered via the template
:file:`flatpages/default.html`, but you can override that for a
particular flatpage: in the admin, a collapsed fieldset titled
"Advanced options" (clicking will expand it) contains a field for
specifying a template name. If you're creating a flat page via the
Python API you can simply set the template name as the field
``template_name`` on the ``FlatPage`` object.
Creating the :file:`flatpages/default.html` template is your responsibility;
in your template directory, just create a :file:`flatpages` directory
containing a file :file:`default.html`.
Flatpage templates are passed a single context variable, ``flatpage``,
which is the flatpage object.
Here's a sample :file:`flatpages/default.html` template:
.. code-block:: html+django
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
"http://www.w3.org/TR/REC-html40/loose.dtd">
<html>
<head>
<title>{{ flatpage.title }}</title>
</head>
<body>
{{ flatpage.content }}
</body>
</html>
Since you're already entering raw HTML into the admin page for a flatpage,
both ``flatpage.title`` and ``flatpage.content`` are marked as **not**
requiring :ref:`automatic HTML escaping <automatic-html-escaping>` in the
template.
Getting a list of :class:`~django.contrib.flatpages.models.FlatPage` objects in your templates
==============================================================================================
.. versionadded:: 1.3
The flatpages app provides a template tag that allows you to iterate
over all of the available flatpages on the :ref:`current site
<hooking-into-current-site-from-views>`.
Like all custom template tags, you'll need to :ref:`load its custom
tag library <loading-custom-template-libraries>` before you can use
it. After loading the library, you can retrieve all current flatpages
via the :ttag:`get_flatpages` tag:
.. code-block:: html+django
{% load flatpages %}
{% get_flatpages as flatpages %}
<ul>
{% for page in flatpages %}
<li><a href="{{ page.url }}">{{ page.title }}</a></li>
{% endfor %}
</ul>
.. templatetag:: get_flatpages
Displaying ``registration_required`` flatpages
----------------------------------------------
By default, the :ttag:`get_flatpages` templatetag will only show
flatpages that are marked ``registration_required = False``. If you
want to display registration-protected flatpages, you need to specify
an authenticated user using a``for`` clause.
For example:
.. code-block:: html+django
{% get_flatpages for someuser as about_pages %}
If you provide an anonymous user, :ttag:`get_flatpages` will behave
the same as if you hadn't provided a user -- i.e., it will only show you
public flatpages.
Limiting flatpages by base URL
------------------------------
An optional argument, ``starts_with``, can be applied to limit the
returned pages to those beginning with a particular base URL. This
argument may be passed as a string, or as a variable to be resolved
from the context.
For example:
.. code-block:: html+django
{% get_flatpages '/about/' as about_pages %}
{% get_flatpages about_prefix as about_pages %}
{% get_flatpages '/about/' for someuser as about_pages %}
