229 lines
6.4 KiB
Plaintext
229 lines
6.4 KiB
Plaintext
.. _topics-http-shortcuts:
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=========================
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Django shortcut functions
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=========================
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.. module:: django.shortcuts
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:synopsis:
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Convience shortcuts that spam multiple levels of Django's MVC stack.
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.. index:: shortcuts
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The package ``django.shortcuts`` collects helper functions and classes that
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"span" multiple levels of MVC. In other words, these functions/classes
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introduce controlled coupling for convenience's sake.
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``render_to_response``
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======================
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.. function:: render_to_response(template[, dictionary][, context_instance][, mimetype])
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Renders a given template with a given context dictionary and returns an
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:class:`~django.http.HttpResponse` object with that rendered text.
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Required arguments
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------------------
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``template``
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The full name of a template to use.
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Optional arguments
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------------------
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``dictionary``
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A dictionary of values to add to the template context. By default, this
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is an empty dictionary. If a value in the dictionary is callable, the
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view will call it just before rendering the template.
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``context_instance``
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The context instance to render the template with. By default, the template
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will be rendered with a ``Context`` instance (filled with values from
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``dictionary``). If you need to use :ref:`context processors
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<subclassing-context-requestcontext>`, render the template with a
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``RequestContext`` instance instead. Your code might look something like
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this::
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return render_to_response('my_template.html',
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my_data_dictionary,
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context_instance=RequestContext(request))
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``mimetype``
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.. versionadded:: 1.0
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The MIME type to use for the resulting document. Defaults to the value of
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the :setting:`DEFAULT_CONTENT_TYPE` setting.
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Example
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-------
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The following example renders the template ``myapp/index.html`` with the
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MIME type ``application/xhtml+xml``::
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from django.shortcuts import render_to_response
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def my_view(request):
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# View code here...
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return render_to_response('myapp/index.html', {"foo": "bar"},
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mimetype="application/xhtml+xml")
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This example is equivalent to::
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from django.http import HttpResponse
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from django.template import Context, loader
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def my_view(request):
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# View code here...
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t = loader.get_template('myapp/template.html')
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c = Context({'foo': 'bar'})
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return HttpResponse(t.render(c),
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mimetype="application/xhtml+xml")
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``redirect``
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============
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.. function:: redirect(to[, permanent=False], *args, **kwargs)
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.. versionadded:: 1.1
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Returns an HttpResponseRedirect to the apropriate URL for the arguments
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passed.
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The arguments could be:
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* A model: the model's `get_absolute_url()` function will be called.
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* A view name, possibly with arguments: `urlresolvers.reverse()` will
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be used to reverse-resolve the name.
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* A URL, which will be used as-is for the redirect location.
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By default issues a temporary redirect; pass permanent=True to issue a
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permanent redirect
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Examples
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--------
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You can use the :func:`redirect` function in a number of ways.
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1. By passing some object; that object's
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:meth:`~django.db.models.Model.get_absolute_url` method will be called
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to figure out the redirect URL::
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def my_view(request):
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...
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object = MyModel.objects.get(...)
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return redirect(object)
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2. By passing the name of a view and optionally some positional or
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keyword arguments; the URL will be reverse resolved using the
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:func:`~django.core.urlresolvers.reverse` method::
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def my_view(request):
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...
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return redirect('some-view-name', foo='bar')
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3. By passing a hardcoded URL to redirect to::
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def my_view(request):
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...
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return redirect('/some/url/')
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This also works with full URLs::
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def my_view(request):
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...
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return redirect('http://example.com/')
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By default, :func:`redirect` returns a temporary redirect. All of the above
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forms accept a ``permanent`` argument; if set to ``True`` a permanent redirect
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will be returned::
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def my_view(request):
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...
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object = MyModel.objects.get(...)
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return redirect(object, permanent=True)
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``get_object_or_404``
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=====================
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.. function:: get_object_or_404(object, *args, **kwargs)
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Calls :meth:`~django.db.models.QuerySet.get()` on a given model manager,
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but it raises ``django.http.Http404`` instead of the model's
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``DoesNotExist`` exception.
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Required arguments
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------------------
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``klass``
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A ``Model``, ``Manager`` or ``QuerySet`` instance from which to get the
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object.
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``**kwargs``
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Lookup parameters, which should be in the format accepted by ``get()`` and
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``filter()``.
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Example
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-------
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The following example gets the object with the primary key of 1 from
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``MyModel``::
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from django.shortcuts import get_object_or_404
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def my_view(request):
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my_object = get_object_or_404(MyModel, pk=1)
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This example is equivalent to::
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from django.http import Http404
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def my_view(request):
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try:
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my_object = MyModel.objects.get(pk=1)
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except MyModel.DoesNotExist:
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raise Http404
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Note: As with ``get()``, an ``MultipleObjectsReturned`` exception will be
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raised if more than one object is found.
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``get_list_or_404``
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===================
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.. function:: get_list_or_404(klass, *args, **kwargs)
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Returns the result of :meth:`~django.db.models.QuerySet.filter()` on a
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given model manager, raising ``django.http.Http404`` if the resulting list
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is empty.
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Required arguments
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------------------
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``klass``
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A ``Model``, ``Manager`` or ``QuerySet`` instance from which to get the
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object.
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``**kwargs``
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Lookup parameters, which should be in the format accepted by ``get()`` and
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``filter()``.
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Example
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-------
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The following example gets all published objects from ``MyModel``::
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from django.shortcuts import get_list_or_404
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def my_view(request):
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my_objects = get_list_or_404(MyModel, published=True)
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This example is equivalent to::
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from django.http import Http404
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def my_view(request):
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my_objects = list(MyModel.objects.filter(published=True))
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if not my_objects:
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raise Http404
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