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django/docs/topics/http/shortcuts.txt
Ramiro Morales 932b1b8d6d Converted links to external topics so they use intersphinx extension markup.
This allows to make these links more resilent to changes in the target URLs.
Thanks Jannis for the report and Aymeric Augustin for the patch.

Fixes #16586.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16720 bcc190cf-cafb-0310-a4f2-bffc1f526a37
2011-09-04 21:17:30 +00:00

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=========================
Django shortcut functions
=========================
.. module:: django.shortcuts
:synopsis:
Convenience shortcuts that spam multiple levels of Django's MVC stack.
.. index:: shortcuts
The package ``django.shortcuts`` collects helper functions and classes that
"span" multiple levels of MVC. In other words, these functions/classes
introduce controlled coupling for convenience's sake.
``render``
==========
.. function:: render(request, template[, dictionary][, context_instance][, content_type][, status][, current_app])
.. versionadded:: 1.3
Combines a given template with a given context dictionary and returns an
:class:`~django.http.HttpResponse` object with that rendered text.
:func:`render()` is the same as a call to
:func:`render_to_response()` with a `context_instance` argument that
forces the use of a :class:`~django.template.RequestContext`.
Required arguments
------------------
``request``
The request object used to generate this response.
``template``
The full name of a template to use or sequence of template names.
Optional arguments
------------------
``dictionary``
A dictionary of values to add to the template context. By default, this
is an empty dictionary. If a value in the dictionary is callable, the
view will call it just before rendering the template.
``context_instance``
The context instance to render the template with. By default, the template
will be rendered with a ``RequestContext`` instance (filled with values from
``request`` and ``dictionary``).
``content_type``
The MIME type to use for the resulting document. Defaults to the value of
the :setting:`DEFAULT_CONTENT_TYPE` setting.
``status``
The status code for the response. Defaults to ``200``.
``current_app``
A hint indicating which application contains the current view. See the
:ref:`namespaced URL resolution strategy <topics-http-reversing-url-namespaces>`
for more information.
Example
-------
The following example renders the template ``myapp/index.html`` with the
MIME type :mimetype:`application/xhtml+xml`::
from django.shortcuts import render
def my_view(request):
# View code here...
return render(request, 'myapp/index.html', {"foo": "bar"},
content_type="application/xhtml+xml")
This example is equivalent to::
from django.http import HttpResponse
from django.template import RequestContext, loader
def my_view(request):
# View code here...
t = loader.get_template('myapp/template.html')
c = RequestContext(request, {'foo': 'bar'})
return HttpResponse(t.render(c),
content_type="application/xhtml+xml")
``render_to_response``
======================
.. function:: render_to_response(template_name[, dictionary][, context_instance][, mimetype])
Renders a given template with a given context dictionary and returns an
:class:`~django.http.HttpResponse` object with that rendered text.
Required arguments
------------------
``template_name``
The full name of a template to use or sequence of template names. If a
sequence is given, the first template that exists will be used. See the
:ref:`template loader documentation <ref-templates-api-the-python-api>`
for more information on how templates are found.
Optional arguments
------------------
``dictionary``
A dictionary of values to add to the template context. By default, this
is an empty dictionary. If a value in the dictionary is callable, the
view will call it just before rendering the template.
``context_instance``
The context instance to render the template with. By default, the template
will be rendered with a :class:`~django.template.Context` instance (filled
with values from ``dictionary``). If you need to use :ref:`context
processors <subclassing-context-requestcontext>`, render the template with
a :class:`~django.template.RequestContext` instance instead. Your code
might look something like this::
return render_to_response('my_template.html',
my_data_dictionary,
context_instance=RequestContext(request))
``mimetype``
The MIME type to use for the resulting document. Defaults to the value of
the :setting:`DEFAULT_CONTENT_TYPE` setting.
Example
-------
The following example renders the template ``myapp/index.html`` with the
MIME type :mimetype:`application/xhtml+xml`::
from django.shortcuts import render_to_response
def my_view(request):
# View code here...
return render_to_response('myapp/index.html', {"foo": "bar"},
mimetype="application/xhtml+xml")
This example is equivalent to::
from django.http import HttpResponse
from django.template import Context, loader
def my_view(request):
# View code here...
t = loader.get_template('myapp/template.html')
c = Context({'foo': 'bar'})
return HttpResponse(t.render(c),
mimetype="application/xhtml+xml")
``redirect``
============
.. function:: redirect(to[, permanent=False], *args, **kwargs)
Returns an :class:`~django.http.HttpResponseRedirect` to the appropriate URL
for the arguments passed.
The arguments could be:
* A model: the model's `get_absolute_url()` function will be called.
* A view name, possibly with arguments: `urlresolvers.reverse()` will
be used to reverse-resolve the name.
* A URL, which will be used as-is for the redirect location.
By default issues a temporary redirect; pass ``permanent=True`` to issue a
permanent redirect
Examples
--------
You can use the :func:`redirect` function in a number of ways.
1. By passing some object; that object's
:meth:`~django.db.models.Model.get_absolute_url` method will be called
to figure out the redirect URL::
def my_view(request):
...
object = MyModel.objects.get(...)
return redirect(object)
2. By passing the name of a view and optionally some positional or
keyword arguments; the URL will be reverse resolved using the
:func:`~django.core.urlresolvers.reverse` method::
def my_view(request):
...
return redirect('some-view-name', foo='bar')
3. By passing a hardcoded URL to redirect to::
def my_view(request):
...
return redirect('/some/url/')
This also works with full URLs::
def my_view(request):
...
return redirect('http://example.com/')
By default, :func:`redirect` returns a temporary redirect. All of the above
forms accept a ``permanent`` argument; if set to ``True`` a permanent redirect
will be returned::
def my_view(request):
...
object = MyModel.objects.get(...)
return redirect(object, permanent=True)
``get_object_or_404``
=====================
.. function:: get_object_or_404(klass, *args, **kwargs)
Calls :meth:`~django.db.models.query.QuerySet.get()` on a given model manager,
but it raises :class:`~django.http.Http404` instead of the model's
:class:`~django.core.exceptions.DoesNotExist` exception.
Required arguments
------------------
``klass``
A :class:`~django.db.models.Model`, :class:`~django.db.models.Manager` or
:class:`~django.db.models.query.QuerySet` instance from which to get the
object.
``**kwargs``
Lookup parameters, which should be in the format accepted by ``get()`` and
``filter()``.
Example
-------
The following example gets the object with the primary key of 1 from
``MyModel``::
from django.shortcuts import get_object_or_404
def my_view(request):
my_object = get_object_or_404(MyModel, pk=1)
This example is equivalent to::
from django.http import Http404
def my_view(request):
try:
my_object = MyModel.objects.get(pk=1)
except MyModel.DoesNotExist:
raise Http404
Note: As with ``get()``, a
:class:`~django.core.exceptions.MultipleObjectsReturned` exception
will be raised if more than one object is found.
``get_list_or_404``
===================
.. function:: get_list_or_404(klass, *args, **kwargs)
Returns the result of :meth:`~django.db.models.query.QuerySet.filter()` on a
given model manager, raising :class:`~django.http.Http404` if the resulting
list is empty.
Required arguments
------------------
``klass``
A :class:`~django.db.models.Model`, :class:`~django.db.models.Manager` or
:class:`~django.db.models.query.QuerySet` instance from which to get the
list.
``**kwargs``
Lookup parameters, which should be in the format accepted by ``get()`` and
``filter()``.
Example
-------
The following example gets all published objects from ``MyModel``::
from django.shortcuts import get_list_or_404
def my_view(request):
my_objects = get_list_or_404(MyModel, published=True)
This example is equivalent to::
from django.http import Http404
def my_view(request):
my_objects = list(MyModel.objects.filter(published=True))
if not my_objects:
raise Http404