table of Contents

A, DRF mounting frame

DRF is a Django plugin, so you want to install Django in advance
Run commandpip install djangorstframework
To register app in settings.py use DRF:INSTALLED_APPS = [..., 'rest_framework']
CBV completed based on the interface specification to meet RSSTful

Second, the interface

(A) What is the interface

Provides for submission: Interface request parameters of the request method , you can get access to it in response to feedback data of url links
Four features
1. url link: link url looks like a return data
2. Request method: get, post, put, patch, delete
3. Request Parameters: key-valu e data type or xml format json
4. Response result: xml format data or json

(B) Interface Specification (RESTful)

(1) url links

Using the https protocol: an interface station data are data before and after the operation, it is necessary to ensure the security of data
API key: The interface used to manipulate data, and URL (operation page) are different, so the use of a specific keyword indicates
Resource terminology: called data interface resources, reflected only in the url resource name, resource does not reflect the manner (https://api.baidu.com/get_books/), but rather to determine the operating mode for requesting resources the way
- General Resource Interface
  1. https://api.baidu.com/books/
  2. https://api.baidu.com/books/(pk)/
- Unconventional interfaces: a resource and not a particularly close or more than one resource
  1. https://api.baidu.com/books/login/
  2. https://api.baidu.com/books/place/search/
Multi-version coexistence: If there are multiple versions of a resource results in url link to use specific symbols compatible with multi-version coexistence
- https://api.baidu.com/v1/books/
- https://api.baidu.com/v2/books/
? Restrictions: resource group operating in general as well as additional restrictions, such as sorting, limit testing, pagination, etc.
- https://api.baidu.com/v1/books/?ordering=price&limit=3/

(2) request method

get request: Get single or multiple resource
- https://api.baidu.com/books/: group search returns multiple result objects
- https://api.baidu.com/books/(pk)/: single check, returns a result object
post request: add single or multiple resource
- https://api.baidu.com/books: single whole and by increasing both the interface for a single or multiple return result objects
put request: single or a plurality of resources to modify the overall
- https://api.baidu.com/books/: modifying a plurality of integrally providing a plurality of dictionary data (the primary key to be included) in the array, the group completed change, return multiple result objects
- https://api.baidu.com/books/(pk)/: modify a single whole, provided a single data dictionary (embodied in the url primary key), a single change is completed, return a single result object
patch request: single or multiple local modification of resource (common)
- Exactly the same way and put
- Different points: resource operation if five key key-value pair, provides PUT request dictionary must contain full, but the patch to provide a key dictionary contains 0 to 5 can be
delete request: Delete single or multiple resources
- https://api.baidu.com/books/: Multi-delete, providing more resources to primary key data, no resources to return (usually custom information returned result: success or failure)
- https://api.baidu.com/books/(pk)/: single delete, do not need to provide additional data, no resources to return (usually custom information returned result: success or failure)

(3) a response result

Network Status Code: response object to include in the network state (network status information and network status code bundle occurs, no extra setting)
- 1xx: Basic Information
- 2xx: Success
  - 200: Basic
  - 201: What's New Success
- 3xx: Redirection
- 4xx: Client Error
  - 400: Bad Request
  - 403: no permission request
  - 404: requested resource does not exist
- 5xx: server error
  - 500: Server Error
Data status code (usually around the table agreed rules, specific information to be written in a clear interface document)
- 0: Success
- 1: Failed
- 2: No data
Data Status Code Information: General interpretation of the data is not only the status code, the result is a description of more of the developer to the front and rear ends of the reading
```
{
    "status":0,
    'msg':'ok'
}
```

Data result (constants, arrays, dictionaries), if there are sub-resource (images, video, audio), returns connection resources url

{
    "status":0,
    "msg":'ok',
    "results":[{
        "name":"西游记",
        "img":"https://api.naidu.com/book/xyj.jpg"
    },{}]
}

(C) Data Interface Documentation: YApi

Where YApi is a large network of front-end technology center open-source visualization interface management platform
Can build on any local or cloud server, complete the preparation of the interface at the time of project development background
YApi test site: http://yapi.demo.qunar.com/

(D) Postman interface testing tool

Postman is a free visual interface to debugging tools, and support a variety of operating platforms
Postman Download: https://www.getpostman.com/downloads/

Three, DRF request lifecycle (CBV source)

Project starts, it will automatically execute as_view method, return to the calling function view (FBV is essentially)

View function returns the dispatch method of calling object

@classonlymethod
def as_view(cls, **initkwargs):
    for key in initkwargs:……  # initkwargs没有进行赋值，该逻辑不会执行 
    def view(request, *args, **kwargs):  # 请求来了完成响应的函数
        self = cls(**initkwargs)  # cls是我们自己写的类 MyLogin  self是我们自己定义的类的对象

        self.request = request  # wsgi协议包装数据后的request 
        self.args = args  # 无名分组参数
        self.kwargs = kwargs  # 有名分组参数
        return self.dispatch(request, *args, **kwargs)  # view返回什么，用户就能看到什么

    # 将请求来调用view的修改信息保存在view对象中
    view.view_class  = cls
    view.view_initkwargs = initkwargs

    # 看源码的时候一定要注意在查找属性和方法的时候先从对象自身找，再去类中查找，再去父类查找
    return view  # 返回请求调用的函数地址，进行路由绑定

dispatch function using the reflection method of obtaining a mode request to call the corresponding methods

def dispatch(self, request, *args, **kwargs):
    # Try to dispatch to the right method; if a method doesn't exist,
    # defer to the error handler. Also defer to the error handler if the
    # request method isn't on the approved list.
    # 判断当前请求方式在不在默认的八个方法内
    # 1.先以GET请求为例
    if request.method.lower() in self.http_method_names:
        # 利用反射去我们自己定义类的对象中查找get属性或者是方法  getattr(obj,'get')
        # handler = get方法
        handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
    else:
        handler = self.http_method_not_allowed
    return handler(request, *args, **kwargs)  # 调用get方法

Fourth, the use DEBUG function

(Day70) DRF mounting, the interface, the CBV source, the DEBUG function