mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2024-12-23 01:25:58 +00:00
Code Issues 25 Releases Wiki Activity

Beefed up docs/url_dispatch.txt

Browse Source 
git-svn-id: http://code.djangoproject.com/svn/django/trunk@1291 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Adrian Holovaty 2005-11-19 18:20:30 +00:00
parent cdbc94dbd2
commit f125fb0afc
3 changed files with 255 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
docs/overview.txt
View File

@ -162,9 +162,9 @@ Reporter/Article example, here's what that might look like::
from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^/articles/(?P<year>\d{4})/$', 'myproject.news.views.articles.year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'myproject.news.views.articles.month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<article_id>\d+)/$', 'myproject.news.views.articles.article_detail'),
(r'^/articles/(?P<year>\d{4})/$', 'myproject.news.views.year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'myproject.news.views.month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<article_id>\d+)/$', 'myproject.news.views.article_detail'),
)
The code above maps URLs, as regular expressions, to the location of Python
@ -181,7 +181,7 @@ dictionaries -- and the values captured in the regex, via keyword
arguments.
For example, if a user requested the URL "/articles/2005/05/39323/", Django
would call the function ``myproject.news.views.articles.article_detail(request,
would call the function ``myproject.news.views.article_detail(request,
year='2005', month='05', article_id='39323')``.
Write your views
@ -280,8 +280,8 @@ This has been only a quick overview of Django's functionality. Some more useful
features:
* A caching framework that integrates with memcached or other backends.
* An RSS framework that makes creating RSS feeds as easy as writing a
small Python class.
* A syndication framework that makes creating RSS and Atom feeds as easy as
writing a small Python class.
* More sexy automatically-generated admin features -- this overview barely
scratched the surface.

14
docs/tutorial03.txt
View File

@ -60,6 +60,7 @@ regular expression as keyword arguments, and, optionally, arbitrary keyword
arguments from the dictionary (an optional third item in the tuple).
For more on ``HTTPRequest`` objects, see the `request and response documentation`_.
For more details on URLconfs, see the `URLconf documentation`_.
When you ran ``django-admin.py startproject myproject`` at the beginning of
Tutorial 1, it created a default URLconf in ``myproject/urls.py``. It also
@ -67,8 +68,7 @@ automatically set your ``ROOT_URLCONF`` setting to point at that file::
ROOT_URLCONF = 'myproject.urls'
Time for an example. Edit ``myproject/urls.py`` so it looks like
this::
Time for an example. Edit ``myproject/urls.py`` so it looks like this::
from django.conf.urls.defaults import *
@ -88,9 +88,9 @@ associated Python package/module: ``myproject.apps.polls.views.detail``. That
corresponds to the function ``detail()`` in ``myproject/apps/polls/views.py``.
Finally, it calls that ``detail()`` function like so::
detail(request=<HttpRequest object>, poll_id=23)
detail(request=<HttpRequest object>, poll_id='23')
The ``poll_id=23`` part comes from ``(?P<poll_id>\d+)``. Using
The ``poll_id='23'`` part comes from ``(?P<poll_id>\d+)``. Using
``(?P<name>pattern)`` "captures" the text matched by ``pattern`` and sends it
as a keyword argument to the view function.
@ -103,6 +103,11 @@ something like this::
But, don't do that. It's silly.
Note that these regular expressions do not search GET and POST parameters, or
the domain name. For example, in a request to ``http://www.example.com/myapp/``,
the URLconf will look for ``/myapp/``. In a request to
``http://www.example.com/myapp/?page=3``, the URLconf will look for ``/myapp/``.
If you need help with regular expressions, see `Wikipedia's entry`_ and the
`Python documentation`_. Also, the O'Reilly book "Mastering Regular
Expressions" by Jeffrey Friedl is fantastic.
@ -113,6 +118,7 @@ time the URLconf module is loaded. They're super fast.
.. _Wikipedia's entry: http://en.wikipedia.org/wiki/Regular_expression
.. _Python documentation: http://www.python.org/doc/current/lib/module-re.html
.. _request and response documentation: http://www.djangoproject.com/documentation/request_response/
.. _URLconf documentation: http://www.djangoproject.com/documentation/url_dispatch/
Write your first view
=====================

271
docs/url_dispatch.txt
View File

@ -2,52 +2,244 @@
URL dispatcher
==============
We're fanatics about good URLs. No ".php" or ".cgi", and certainly not any of
that "0,2097,1-1-1928,00" nonsense. Django's URL dispatcher lets you design
your URLs to be as pretty as the rest of your application.
A clean, elegant URL scheme is an important detail in a high-quality Web
application. Django lets you design URLs however you want, with no framework
limitations.
See `the Django overview`_ for a quick introduction to URL configurations; this
document will continue from there.
There's no ``.php`` or ``.cgi`` required, and certainly none of that
``0,2097,1-1-1928,00`` nonsense.
.. _`the Django overview`: http://www.djangoproject.com/documentation/overview/#design-your-urls
See `Cool URIs don't change`_, by World Wide Web creator Tim Berners-Lee, for
excellent arguments on why URLs should be clean and usable.
The view prefix
===============
.. _http://www.w3.org/Provider/Style/URI: Cool URIs don't change
Here's the example from that overview::
Overview
========
To design URLs for an app, you create a Python module informally called a
**URLconf** (URL configuration). This module is pure Python code and
is a simple mapping between URL patterns (as simple regular expressions) to
Python callback functions (your views).
This mapping can be as short or as long as needed. It can reference other
mappings. And, because it's pure Python code, it can be constructed
dynamically.
How Django processes a request
==============================
When a user requests a page from your Django-powered site, this is the
algorithm the system follows to determine which Python code to execute:
1. The system looks at the ``ROOT_URLCONF`` setting in your
`settings file`_. This should be a string representing the full Python
import path to your URLconf. For example: ``"mydjangoapps.urls"``.
2. The system loads that Python module and looks for the variable
``urlpatterns``. This should be a Python list, in the format returned
by the function ``django.conf.urls.defaults.patterns()``.
3. The system runs through each URL pattern, in order, and stops at the
first one that matches the requested URL.
4. Once one of the regexes matches, Django imports and calls the given
view, which is a simple Python function. The view gets passed a
`request object`_ and any values captured in the regex as keyword
arguments.
.. _settings file: http://www.djangoproject.com/documentation/settings/
.. _request object: http://www.djangoproject.com/documentation/request_response/#httprequest-objects
Example
=======
Here's a sample URLconf::
from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^/articles/(?P<year>\d{4})/$', 'myproject.news.views.articles.year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'myproject.news.views.articles.month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d+)/$', 'myproject.news.views.articles.article_detail'),
(r'^/articles/2003/$', 'news.views.special_case_2003'),
(r'^/articles/(?P<year>\d{4})/$', 'news.views.year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'news.views.month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d+)/$', 'news.views.article_detail'),
)
The first argument to ``patterns`` is an empty string in the above example, but
that argument can be useful. The first argument is prepended to all the view
functions in the urlpatterns list, so the above example could be written more
concisely as::
Notes:
urlpatterns = patterns('myproject.news.views.articles',
* ``from django.conf.urls.defaults import *`` makes the ``patterns``
function available.
* To capture a value from the URL, use the syntax ``(?P<name>pattern)``,
where ``name`` is the name for that value and ``pattern`` is some pattern
to match.
* The ``"r"`` in front of each regular expression string is optional but
recommended. It tells Python that a string is "raw" -- that nothing in
the string should be escaped. See `Dive Into Python's explanation`_.
Examples:
* A request to ``/articles/2005/03/`` would match the third entry in the
list. Django would call the function
``news.views.month_archive(request, year='2005', month='03')``.
* ``/articles/2005/3/`` would not match any URL patterns, because the
third entry in the list requires two digits for the month.
* ``/articles/2003/`` would match the first pattern in the list, not the
second one, because the patterns are tested in order, and the first one
is the first test to pass. Feel free to exploit the ordering to insert
special cases like this.
* ``/articles/2003`` would not match any of these patterns, because each
pattern requires that the URL end with a slash.
* ``/articles/2003/03/3/`` would match the final pattern. Django would call
the function
``news.views.article_detail(request, year='2003', month='03', day='3')``.
.. _Dive Into Python's explanation: http://diveintopython.org/regular_expressions/street_addresses.html#re.matching.2.3
What the URLconf searches against
=================================
The URLconf searches against the requested URL, as a normal Python string. This
does not include GET or POST parameters, or the domain name.
For example, in a request to ``http://www.example.com/myapp/``, the URLconf
will look for ``/myapp/``.
In a request to ``http://www.example.com/myapp/?page=3``, the URLconf will look
for ``/myapp/``.
Syntax of the urlpatterns variable
==================================
``urlpatterns`` should be a Python list, in the format returned by the function
``django.conf.urls.defaults.patterns()``. Always use ``patterns()`` to create
the ``urlpatterns`` variable.
Convention is to use ``from django.conf.urls.defaults import *`` at the top of
your URLconf. This gives your module access to these objects:
patterns
--------
A function that takes a prefix an arbitrary number of URL patterns and returns
a list of URL patterns in the format Django needs.
The first argument to ``patterns()`` is a string ``prefix``. See
"The view prefix" below.
The remaining arguments should be tuples in this format::
(regular expression, Python callback function [, optional dictionary])
...where ``dictionary_of_extra_arguments`` is optional. (See
"Passing extra options to view functions" below.)
handler404
----------
A string representing the full Python import path to the view that should be
called if none of the URL patterns match.
By default, this is ``'django.views.defaults.page_not_found'``. That default
value should suffice.
handler500
----------
A string representing the full Python import path to the view that should be
called in case of server errors. Server errors happen when you have runtime
errors in view code.
By default, this is ``'django.views.defaults.server_error'``. That default
value should suffice.
include
-------
A function that takes a full Python import path to another URLconf that should
be "included" in this place. See "Including other URLconfs" below.
Notes on capturing text in URLs
===============================
Each captured argument is sent to the view as a plain Python string, regardless
of what sort of match the regular expression makes. For example, in this
URLconf::
(r'^/articles/(?P<year>\d{4})/$', 'news.views.year_archive'),
...the ``year`` argument to ``news.views.year_archive()`` will be a string, not
an integer, even though the ``\d{4}`` will only match integer strings.
A convenient trick is to specify default parameters for your views' arguments.
Here's an example URLconf and view::
# URLconf
urlpatterns = patterns('',
(r'^/blog/$', 'blog.views.page'),
(r'^/blog/page(?P<num>\d+)/$', 'blog.views.page'),
)
# View (in blog/views.py)
def page(request, num="1"):
# Output the appropriate page of blog entries, according to num.
In the above example, both URL patterns point to the same view --
``blog.views.page`` -- but the first pattern doesn't capture anything from the
URL. If the first pattern matches, the ``page()`` function will use its
default argument for ``num``, ``"1"``. If the second pattern matches,
``page()`` will use whatever ``num`` value was captured by the regex.
Performance
===========
Each regular expression in a ``urlpatterns`` is compiled the first time it's
accessed. This makes the system blazingly fast.
The view prefix
===============
You can specify a common prefix in your ``patterns()`` call, to cut down on
code duplication.
Here's the example URLconf from the `Django overview`_::
from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^/articles/(?P<year>\d{4})/$', 'myproject.news.views.year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'myproject.news.views.month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d+)/$', 'myproject.news.views.article_detail'),
)
In this example, each view has a common prefix -- ``"myproject.news.views"``.
Instead of typing that out for each entry in ``urlpatterns``, you can use the
first argument to the ``patterns()`` function to specify a prefix to apply to
each view function.
With this in mind, the above example can be written more concisely as::
from django.conf.urls.defaults import *
urlpatterns = patterns('myproject.news.views',
(r'^/articles/(?P<year>\d{4})/$', 'year_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/$', 'month_archive'),
(r'^/articles/(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d+)/$', 'article_detail'),
)
.. admonition:: Note
More precisely, the actual view function used is ``prefix + "." +
function_name``. The trailing "dot" does not need to be put in the prefix.
Note that you don't put a trailing dot (``"."``) in the prefix. Django puts
that in automatically.
Including other URLconfs
========================
You can also "include" other URLconf modules at any point along the path. This
essentially "roots" a set of URLs below other ones. This is most often used
for a site's "base" URLconf; the ``ROOT_URLCONF`` setting points to a urlconf
module that will be used for the entire site. Here's the URLconf for the
`Django website`_ itself. It includes a number of other URLconfs::
At any point, your ``urlpatterns`` can "include" other URLconf modules. This
essentially "roots" a set of URLs below other ones.
For example, here's the URLconf for the `Django website`_ itself. It includes a
number of other URLconfs::
from django.conf.urls.defaults import *
@ -70,6 +262,7 @@ URLconfs, so the following example is valid::
urlpatterns = patterns('foo.views'
(r'^$', 'blog.index'),
(r'^archive/$', 'blog.archive'),
)
In the above example, the captured ``"username"`` variable is passed to the
included URLconf, as expected.
@ -79,11 +272,25 @@ included URLconf, as expected.
Passing extra options to view functions
=======================================
There are two ways of passing arguments into your view functions: named captures
from the regex (which you've already seen) and the optional third element
in URLconf tuples. This third element can be a dictionary of extra keyword
arguments that will be passed to the view function::
URLconfs have a hook that lets you pass extra arguments to your view functions,
as a Python dictionary.
urlpatterns = patterns('myproject.news.views.articles',
(r'^/articles/(?P<year>\d{4})/$', 'year_archive', {key: value, key2: value2}),
Any URLconf tuple can have an optional third element, which should be a
dictionary of extra keyword arguments to pass to the view function.
For example::
urlpatterns = patterns('blog.views',
(r'^/blog/(?P<year>\d{4})/$', 'year_archive', {'foo': 'bar'}),
)
In this example, for a request to ``/blog/2005/``, Django will call the
``blog.views.year_archive()`` view, passing it these keyword arguments::
year='2005', foo='bar'
This technique is used in `generic views`_ and in the `syndication framework`_
to pass metadata and options to views.
.. _generic views: http://www.djangoproject.com/documentation/generic_views/
.. _syndication framework: http://www.djangoproject.com/documentation/syndication/