DRF - web development mode, API interface, API interface testing tool, restful specification, serialization and deserialization, DRF installation and use

List of articles

drf
Chapter one django web Development mode 、api Interface 、api Interface testing tool 、restful standard 、 Serialization deserialization 、drf Install and use

Chapter two drf Use 、APIView Source code analysis 、Request Source code analysis 、Serializer Serialization

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Preface

Learned before django Template layer of 、 The routing layer 、 View layer 、 The model layer , So let's start learning django Of drf Use of third-party plug-ins

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One 、web Development mode

web Development falls into two broad categories ：
1. Mixed development without separation of front and back ends
For hybrid development , The impact between front-end and back-end projects is great , Once the front-end or back-end changes, it will cause a chain reaction , Such development will make the efficiency insufficient , At the same time, it causes more bug The emergence of makes error checking more difficult to find .

2. Separate front and rear development
The separation of the front and rear ends makes , The front end and the back end perform their respective duties , Let's do our best . There is a change , Can be easily combined , Improve the development efficiency, and it is more convenient to troubleshoot errors .

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Two 、api Interface

The medium of front and back information interaction

front end —》 Interface —》 Back end

front end 《— Interface 《— Back end

adopt api The interface converts the data type and sends it to the front-end or back-end implementation , Interaction between front and back ends

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3、 ... and 、api Interface testing tool

postman Originally free software, but later began to charge , This software is highly used
postwoman imitation postman Developed software , It's open source and free

Aim at postwoman The installation process is basically the next step .

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Four 、restful standard

To write api Interface in order to reduce api The use of , When writing, the mainstream is to follow restful Specification

1. Use https Data interaction

https Is based on http Based on the protocol tsl/ssl Encrypt data , While using api It is required to use https To interact with data

2. Interface address with api identification

To write api The interface needs to be marked as a api Interface instead of the corresponding file 、 Page etc.
for example ：

https://api.baidu.com/books    The identity is in the domain name 
https://www.baidu.com/api      The identity is in the address 

3. Identify the version ID in the interface address

If a standard application adapts to the application of the old version, it needs to use the version to identify the corresponding api Interface

for example ：

-https://api.baidu.com/v1   # Use here v Add numbers to indicate api edition 
-https://api.weibo.com/2/statuses/user_timeline.json # Numbers are used here to indicate api edition 

4. Data is a resource , They all use nouns , Do not appear verbs

Writing api Interface is no longer url Use the verb , avoid api Repeated compilation of interfaces , Can also increase api Interface security

for example ：

https://api.baidu.com/v1/user_login # This is wrong 
https://api.baidu.com/v1/user # This writing is correct 

5. Resource operation is determined by the request mode

For the same interface, it needs to produce multiple functions , This requires the request mode to decide what function to call
for example ：

https://api.baidu.com/v1/user  Use post Request to add data 
https://api.baidu.com/v1/user  Use pdelete Request to delete data 
https://api.baidu.com/v1/user  Use put Request to modify the data 
https://api.baidu.com/v1/user  Use get Request to query the data 

6. Address with search criteria

When we need corresponding parameters to send a request, we can directly send it in the corresponding request url You can carry it after
for example ：

https://api.baidu.com/v1/user?username=bbs123&user_id=1

7. Response status code

The response status code can make the development process clear and know the problem
for example ：

1XX  The request is being processed 
2XX  The request is successful   Common are  200 The request is successful  201 Create success 
3XX  Redirect   Common are  301 Temporary redirection  302 Permanent redirection 
4XX  Client error   Common are  403 No omnidirectional  404 The resource address is not used 
5XX  Server error   Common are  500 Encountered a request that I don't know how to handle  501 The requested method is not supported  502 The server cannot respond to the request 

8. There is an error message in the response

When the request is successfully triggered , The response returned by the server will be accompanied by the corresponding response status code and the corresponding status information
for example ：

{
    'code':200, 'msg':' Registered successfully '}

9. The result returned by the response should conform to the specification

for example ：

GET /collection： Returns a list of resource objects （ Array ） 
 The result returned by the response ：[{
    'food_name':' Apple ', 'num':5,'price'：12},{
    'food_name':' pears ', num:8,price：12}]
GET /collection/resource： Return a single resource object 
 The result returned by the response ：{
    'food_name':' Apple ', 'num':5,'price'：12}
POST /collection： Return the newly generated resource object 
 The result returned by the response ：{
    'food_name':' Apple ', 'num':5,'price'：12}
PUT /collection/resource： Returns the complete resource object 
 The result returned by the response ：{
    'food_name':' Apple ', 'num':5,'price'：12}
PATCH /collection/resource： Returns the complete resource object 
 The result returned by the response ：{
    'food_name':' Apple ', 'num':5,'price'：12}
DELETE /collection/resource： Return an empty document 
 The result returned by the response ：[]

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5、 ... and 、 Serialization and deserialization

Serialization refers to converting the written content into a format that the receiver can parse
Deserialization refers to the conversion of data , Through the conversion method given by the sender, the direction is resolved to the data format that the receiver can use

At this time, the information transmission between the front and back ends can be realized through serialization and deserialization

Serialization and deserialization are also api Key knowledge of interface

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6、 ... and 、drf install

drf Namely djangorestframework Abbreviation , It is djagno One of the app（ Third party plug-ins ）, Can only be used in django On the frame

drf It can help developers write quickly api Interface

drf and django The version of has a certain correspondence

Mode one
pip3 install djangorestframework

Mode two ：
stay pycharm Search for installation

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7、 ... and 、drf Quick to use

The model layer
models.py

from django.db import models

# Create your models here.


class Book(models.Model):
    name=models.CharField(max_length=32)
    price=models.IntegerField()

drf Registration of
serializer.py

from rest_framework import serializers
from .models import Book
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model=Book
        fields='__all__'

View layer
views.py

from django.shortcuts import render

# Create your views here.


from rest_framework.viewsets import ModelViewSet
from .models import Book
from .serializer import BookSerializer
class BookView(ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializer

Then you can call api Interface to directly add, delete, modify and query
for example ：

https://127.0.0.1:8080/book  # At this time to use get You can get all the book information objects 
https://127.0.0.1:8080/book
#formdata Carry the corresponding book title and price in use post You can add books by requesting