Django shortcut functions

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()

render(request, template_name, context=None, content_type=None, status=None, using=None)[źródło]

Łączy podany szablon z podanym słownikiem kontekstu i zwraca obiekt HttpResponse z tym wyrenderowanym tekstem.

Django nie dostarcza funkcji skrótowej, która zwraca TemplateResponse, ponieważ konstruktor TemplateResponse oferuje ten sam poziom wygody co render().

Wymagane argumenty

request

Obiekt żądania użyty do wygenerowania tej odpowiedzi

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 template loading documentation for more information on how templates are found.

Optional arguments

context

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.

content_type

The MIME type to use for the resulting document. Defaults to 'text/html'.

status

The status code for the response. Defaults to 200.

using

The NAME of a template engine to use for loading the template.

Przykład

The following example renders the template myapp/index.html with the MIME type 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 loader


def my_view(request):
    # View code here...
    t = loader.get_template("myapp/index.html")
    c = {"foo": "bar"}
    return HttpResponse(t.render(c, request), content_type="application/xhtml+xml")

redirect()

redirect(to, *args, permanent=False, **kwargs)[źródło]

Returns an 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: reverse() will be used to reverse-resolve the name.

  • An absolute or relative 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.

Przykłady

You can use the redirect() function in a number of ways.

  1. By passing some object; that object’s get_absolute_url() method will be called to figure out the redirect URL:

    from django.shortcuts import redirect
    
    
    def my_view(request):
        ...
        obj = MyModel.objects.get(...)
        return redirect(obj)
    
  2. By passing the name of a view and optionally some positional or keyword arguments; the URL will be reverse resolved using the 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("https://example.com/")
    

By default, 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):
    ...
    obj = MyModel.objects.get(...)
    return redirect(obj, permanent=True)

get_object_or_404()

get_object_or_404(klass, *args, **kwargs)[źródło]
aget_object_or_404(klass, *args, **kwargs)

Asynchronous version: aget_object_or_404()

Calls get() on a given model manager, but it raises Http404 instead of the model’s DoesNotExist exception.

Argumenty

klass

A Model class, a Manager, or a QuerySet instance from which to get the object.

*args

Q objects.

**kwargs

Lookup parameters, which should be in the format accepted by get() and filter().

Przykład

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):
    obj = get_object_or_404(MyModel, pk=1)

This example is equivalent to:

from django.http import Http404


def my_view(request):
    try:
        obj = MyModel.objects.get(pk=1)
    except MyModel.DoesNotExist:
        raise Http404("No MyModel matches the given query.")

The most common use case is to pass a Model, as shown above. However, you can also pass a QuerySet instance:

queryset = Book.objects.filter(title__startswith="M")
get_object_or_404(queryset, pk=1)

The above example is a bit contrived since it’s equivalent to doing:

get_object_or_404(Book, title__startswith="M", pk=1)

but it can be useful if you are passed the queryset variable from somewhere else.

Finally, you can also use a Manager. This is useful for example if you have a custom manager:

get_object_or_404(Book.dahl_objects, title="Matilda")

You can also use related managers:

author = Author.objects.get(name="Roald Dahl")
get_object_or_404(author.book_set, title="Matilda")

Note: As with get(), a MultipleObjectsReturned exception will be raised if more than one object is found.

Changed in Django 5.0:

aget_object_or_404() function was added.

get_list_or_404()

get_list_or_404(klass, *args, **kwargs)[źródło]
aget_list_or_404(klass, *args, **kwargs)

Asynchronous version: aget_list_or_404()

Returns the result of filter() on a given model manager cast to a list, raising Http404 if the resulting list is empty.

Argumenty

klass

A Model, Manager or QuerySet instance from which to get the list.

*args

Q objects.

**kwargs

Lookup parameters, which should be in the format accepted by get() and filter().

Przykład

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("No MyModel matches the given query.")
Changed in Django 5.0:

aget_list_or_404() function was added.

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