django/docs/intro/tutorial06.txt

=====================================
Writing your first Django app, part 6
=====================================

This tutorial begins where :doc:`Tutorial 5 </intro/tutorial05>` left off.
We've built a tested Web-poll application, and we'll now add a stylesheet and
an image.

Aside from the HTML generated by the server, web applications generally need
to serve additional files — such as images, JavaScript, or CSS — necessary to
render the complete web page. In Django, we refer to these files as "static
files".

For small projects, this isn't a big deal, because you can just keep the
static files somewhere your web server can find it. However, in bigger
projects -- especially those comprised of multiple apps -- dealing with the
multiple sets of static files provided by each application starts to get
tricky.

That's what ``django.contrib.staticfiles`` is for: it collects static files
from each of your applications (and any other places you specify) into a
single location that can easily be served in production.

Customize your *app's* look and feel
====================================

First, create a directory called ``static`` in your ``polls`` directory. Django
will look for static files there, similarly to how Django finds templates
inside ``polls/templates/``.

Django's :setting:`STATICFILES_FINDERS` setting contains a list
of finders that know how to discover static files from various
sources. One of the defaults is ``AppDirectoriesFinder`` which
looks for a "static" subdirectory in each of the
:setting:`INSTALLED_APPS`, like the one in ``polls`` we just created. The admin
site uses the same directory structure for its static files.

Within the ``static`` directory you have just created, create another directory
called ``polls`` and within that create a file called ``style.css``. In other
words, your stylesheet should be at ``polls/static/polls/style.css``. Because
of how the ``AppDirectoriesFinder`` staticfile finder works, you can refer to
this static file in Django simply as ``polls/style.css``, similar to how you
reference the path for templates.

.. admonition:: Static file namespacing

    Just like templates, we *might* be able to get away with putting our static
    files directly in ``polls/static`` (rather than creating another ``polls``
    subdirectory), but it would actually be a bad idea. Django will choose the
    first static file it finds whose name matches, and if you had a static file
    with the same name in a *different* application, Django would be unable to
    distinguish between them. We need to be able to point Django at the right
    one, and the easiest way to ensure this is by *namespacing* them. That is,
    by putting those static files inside *another* directory named for the
    application itself.

Put the following code in that stylesheet (``polls/static/polls/style.css``):

.. code-block:: css

    li a {
        color: green;
    }

Next, add the following at the top of ``polls/templates/polls/index.html``:

.. code-block:: html+django

    {% load staticfiles %}

    <link rel="stylesheet" type="text/css" href="{% static 'polls/style.css' %}" />

``{% load staticfiles %}`` loads the :ttag:`{% static %} <staticfiles-static>`
template tag from the ``staticfiles`` template library. The ``{% static %}``
template tag generates the absolute URL of the static file.

That's all you need to do for development. Reload
``http://localhost:8000/polls/`` and you should see that the poll links are
green (Django style!) which means that your stylesheet was properly loaded.

Adding a background-image
=========================

Next, we'll create a subdirectory for images. Create an ``images`` subdirectory
in the ``polls/static/polls/`` directory. Inside this directory, put an image
called ``background.gif``. In other words, put your image in
``polls/static/polls/images/background.gif``.

Then, add to your stylesheet (``polls/static/polls/style.css``):

.. code-block:: css

    body {
        background: white url("images/background.gif") no-repeat right bottom;
    }

Reload ``http://localhost:8000/polls/`` and you should see the background
loaded in the bottom right of the screen.

.. warning::

    Of course the ``{% static %}`` template tag is not available for use in
    static files like your stylesheet which aren't generated by Django. You
    should always use **relative paths** to link your static files between each
    other, because then you can change :setting:`STATIC_URL` (used by the
    :ttag:`static` template tag to generate its URLs) without having to modify
    a bunch of paths in your static files as well.

These are the **basics**. For more details on settings and other bits included
with the framework see
:doc:`the static files howto </howto/static-files/index>` and the
:doc:`the staticfiles reference </ref/contrib/staticfiles>`. :doc:`Deploying
static files </howto/static-files/deployment>` discusses how to use static
files on a real server.

What's next?
============

The beginner tutorial ends here for the time being. In the meantime, you might
want to check out some pointers on :doc:`where to go from here
</intro/whatsnext>`.

If you are familiar with Python packaging and interested in learning how to
turn polls into a "reusable app", check out :doc:`Advanced tutorial: How to
write reusable apps</intro/reusable-apps>`.