django/docs/intro/tutorial06.txt

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=====================================
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
: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" type="text/css" 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, 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
:caption: polls/static/polls/style.css
body {
background: white url("images/background.gif") no-repeat;
}
Reload ``http://localhost:8000/polls/`` and you should see the background
loaded in the top left 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
: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.