testbed/django__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 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.

.. admonition:: Where to get help:

    If you're having trouble going through this tutorial, please head over to
    the :doc:`Getting Help</faq/help>` section of the FAQ.

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 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 best 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
    :caption: ``polls/static/polls/style.css``

    li a {
        color: green;
    }

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

.. code-block:: html+django
    :caption: ``polls/templates/polls/index.html``

    {% load static %}

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

The ``{% static %}`` template tag generates the absolute URL of static files.

That's all you need to do for development.

Start the server (or restart it if it's already running):

.. console::

    $ python manage.py runserver

Reload ``http://localhost:8000/polls/`` and you should see that the question
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, add any image
file that you'd like to use as a background. For the purposes of this tutorial,
we're using a file named ``background.png``, which will have the full path
``polls/static/polls/images/background.png``.

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

.. code-block:: css
    :caption: ``polls/static/polls/style.css``

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

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

.. warning::

    The ``{% static %}`` template tag is not available for use in static files
    which aren't generated by Django, like your stylesheet. 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
: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.

When you're comfortable with the static files, read :doc:`part 7 of this
tutorial </intro/tutorial07>` to learn how to customize Django's
automatically-generated admin site.