=========================
Django shortcut functions
=========================
.. module:: django.shortcuts
:synopsis:
Convenience shortcuts that span 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_name[, 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_name``
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
