Django快捷函数

Django快捷函数

包 django.shortcuts 收集助手函数和“跨”多级mvc的类，换句话说，为了方便起见，这些函数/类引入受控耦合。

render()

render(request, template_name, context=None, content_type=None, status=None, using=None)[源代码]
将给定的模板与给定的上下文字典组合在一起，并以渲染的文本返回一个 HttpResponse 对象。

Django没有提供返回:class:~django.template.response.TemplateResponse 的快捷函数，因为:class:~django.template.response.TemplateResponse 的构造函数提供了与:func:`render()`相同的方便程度。

必选参数

request
用于生成此响应的请求对象。
template_name
要使用的模板的全名或模板名称的序列。如果给定一个序列，则将使用存在的第一个模板。有关如何查找模板的更多信息，请参见 template loading documentation 。

可选参数

context
要添加到模板上下文的值的字典。默认情况下，这是一个空的字典。如果字典中的值是可调用的，则视图将在渲染模板之前调用它。
content_type
用于结果文档的MIME类型默认为：设置:setting:DEFAULT_CONTENT_TYPE 设置的值。
status
响应的状态代码默认为“200”。
using
用于加载模板的模板引擎的 :setting:`NAME ` 。

例如

下面的示例使用MIME类型呈现模板myapp/index.html 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')

此示例相当于：

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')

render_to_response()

renderto_response(_template_name, context=None, content_type=None, status=None, using=None)[源代码]

2.0 版后已移除.

该函数之前引入了:func:render ，并类似地工作，只是它不使响应中的 request 可用。

redirect()

redirect(to, *args, permanent=False, **kwargs)[源代码]
将一个 HttpResponseRedirect 返回到传递的参数的适当URL。

论点可以是：

A model: the model's get_absolute_url()function will be called.
A view name, possibly with arguments: reverse() will beused to reverse-resolve the name.
An absolute or relative URL, which will be used as-is for the redirectlocation.By default issues a temporary redirect; pass permanent=True to issue apermanent redirect.

示例

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

By passing some object; that object'sget_absolute_url() method will be calledto figure out the redirect URL:

from django.shortcuts import redirect
 
def my_view(request):
    ...
    obj = MyModel.objects.get(...)
    return redirect(obj)

By passing the name of a view and optionally some positional orkeyword arguments; the URL will be reverse resolved using thereverse() method:

def my_view(request):
    ...
    return redirect('some-view-name', foo='bar')

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 aboveforms accept a permanent argument; if set to True a permanent redirectwill be returned:

def my_view(request):
    ...
    obj = MyModel.objects.get(...)
    return redirect(obj, permanent=True)

get_object_or_404()

getobject_or_404(_klass, *args, **kwargs)[源代码]
Calls get() on a given model manager,but it raises Http404 instead of the model'sDoesNotExist exception.

必选参数

klass
A Model class,a Manager,or a QuerySet instance from which to getthe object.
**kwargs
Lookup parameters, which should be in the format accepted by get() andfilter().

例如

The following example gets the object with the primary key of 1 fromMyModel:

from django.shortcuts import get_object_or_404
 
def my_view(request):
    obj = get_object_or_404(MyModel, pk=1)

此示例相当于：

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, asshown above. However, you can also pass aQuerySet 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 somewhereelse.

Finally, you can also use a Manager. This is usefulfor example if you have acustom manager:

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

You can also userelated managers:

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

Note: As with get(), aMultipleObjectsReturned exceptionwill be raised if more than one object is found.

get_list_or_404()

getlist_or_404(_klass, *args, **kwargs)[源代码]
Returns the result of filter() on agiven model manager cast to a list, raising Http404 ifthe resulting list is empty.

必选参数

klass
A Model, Manager orQuerySet instance from which to get thelist.
**kwargs
Lookup parameters, which should be in the format accepted by get() andfilter().

例如

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)

此示例相当于：

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.")