=========================

Django shortcut functions

=========================

.. module:: django.shortcuts

   :synopsis:

       Convience 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_to_response``

======================

.. function:: render_to_response(template[, 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``

    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 ``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)

   .. versionadded:: 1.1

   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.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.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.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