Djangos framework HttpRequest object details

The HttpRequest object

Remember, how many ways can you use the HTTP protocol to send parameters to the server?

• Extracting specific parts of a URL, such as /weather/ Beijing /2018, can be intercepted using regular expressions in server-side routes;
• Query string key1=value1&key2=value2;
• Data sent in the body of the request, such as form data, JSON, XML;
• In the header of an HTTP packet.

1 URL path parameters

- Position Parameter The position of the parameter must be correct. - Keyword Parameter The position of the parameter can be changed to be the same as the keywordCopy the code

http://127.0. 01.:8000/18/188/
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Positional arguments

• Application of urls. Py

 url(r'^(\d+)/(\d+)/$', views.index),
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• Function in view: The position of the argument cannot be wrong

def index(request, value1, value2) :
      # construct context
      context = {'v1':value1, 'v2':value2}
      return render(request, 'Book/index.html', context)
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Keyword parameter

- among them? The P<value1> part indicates that the name of this parameter is defined as value1 - it can be any other name.r'^(? P
      
       \d+)/(? P
       
        \d+)/$'
       
      , views.index),
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def index(request, value2, value1) :
      # construct context
      context = {'v1':value1, 'v2':value2}
      return render(request, 'Book/index.html', context)
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2 QueryDict objects in Django

The GET and POST attributes of the HttpRequest object are QueryDict objects

Unlike Python dictionaries, objects of type QueryDict deal with multiple values for the same key

• Method get() : gets the value based on the key

  If a key has multiple values at the same time, the last value is retrieved

  Returns None if the key does not exist. You can set the default value for further processing

get('key', default)Copy the code

• Method getList () : gets values by key. Values are returned as a list that can get all the values of the specified key

  If the key does not exist, the empty list [] is returned, and the default can be set for subsequent processing

getlist('key', default)Copy the code

3. Query String Query String

# /get/? a=1&b=2&a=3

def get(request) :
    a = request.GET.get('a')
    b = request.GET.get('b')
    alist = request.GET.getlist('a')
    print(a)  # 3
    print(b)  # 2
    print(alist)  # (' 1 ', '3')
    return HttpResponse('OK')
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4 request body

The format of the request body data is not fixed. It can be a form string, a JSON string, or an XML string and should be treated differently.

The request body data can be sent in POST, PUT, PATCH, or DELETE modes.

Djangos CSRF protection is enabled by default and validates the above request for CSRF protection. You can disable CSRF protection during testing by commenting out the CSRF middleware in settings.py, as shown in the following example:

4.1 Form Type Form Data

def post(request) :
    a = request.POST.get('a')
    b = request.POST.get('b')
    alist = request.POST.getlist('a')
    print(a)
    print(b)
    print(alist)
    return HttpResponse('OK')
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4.2 Non-form Data

Django does not automatically parse non-form request body data. Instead, use the Request. body attribute to retrieve the original request body data and parse the request body data in JSON, XML, etc. Request. body returns bytes.

For example, to get the following JSON data in the request body

{"a": 1."b": 2}
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You can perform the following operations:

import json

def post_json(request) :
    json_str = request.body
    json_str = json_str.decode()  # python3.6 This step is not required
    req_data = json.loads(json_str)
    print(req_data['a'])
    print(req_data['b'])
    return HttpResponse('OK')
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5 request header

def get_headers(request) :
    print(request.META['CONTENT_TYPE'])
    return HttpResponse('OK')
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6 Other common HttpRequest object attributes

• Method: a string that indicates the HTTP method used in a request. Common values include GET and POST.
• User: requested user object.
• Path: A string representing the full path to the requested page, excluding the domain name and parameter parts.
• Encoding: A string that specifies the encoding method of the submitted data.

If it isNoneThe default setting of the browser is UTF -8. This property is writable and can be modified to modify the encoding used to access the form data, and any subsequent access to the property will use the new Encoding value.Copy the code

• FILES: a dictionary-like object that contains all uploaded FILES.