django-rest-framework笔记-序列化篇

一、搭建环境

#新建虚拟环境
virtualenv venv
source venv/bin/activate
#在虚拟环境中安装项目依赖库
cat requirements.txt

coreapi==2.3.1
django==1.11.4
django-filter==1.0.4
django-crispy-forms==1.6.1
django-guardian==1.4.9
httpie-0.9.9
Markdown==2.6.8
Pygments==2.2.0

pip install -r requirements.txt

二、创建项目，配置

#新建项目
django-admin startproject tutorial
#创建应用
cd tutorial
python manage.py startapp snippets

配置：

#将我们新建的snippets app和rest_framework添加到INSTALLED_APPS
INSTALLED_APPS = [
    ...
    'rest_framework',
    'snippets.apps.SnippetsConfig' #Djangp<1.9 替换为snippets
]

#数据库配置
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'rest', # database
        'USER': 'root',
        'PASSWORD': 'root',
        'HOST': '192.168.1.115',
        'OPTIONS': {
            'autocommit': True,
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
        }
    }
}

注：如果mysql-python安装不上去，可以使用pymysql替代

在tutorial包中的__init__.py 将pymysql转为mysql-python

try:
    import pymysql
    pymysql.install_as_MySQLdb()
except ImportError:
    pass

三、模型

编辑文件snippets/models.py

from django.db import models
from pygments.lexers import get_all_lexers
from pygments.styles import get_all_styles

LEXERS = [item for item in get_all_lexers() if item[1]]
LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS])
STYLE_CHOICES = sorted((item, item) for item in get_all_styles())


class Snippet(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=100, blank=True, default='')
    code = models.TextField()
    linenos = models.BooleanField(default=False)
    language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100)
    style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100)

    class Meta:
        ordering = ('created',)

创建表

python manage.py makemigrations snippets
python manage.py migrate

四、序列化

新建snippets/serializers.py文件

#!/usr/bin/env python
# coding:utf-8
from __future__ import absolute_import, print_function, division
from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES


class SnippetSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(required=False, allow_blank=True, max_length=100)
    code = serializers.CharField(style={'base_template': 'textarea.html'})
    linenos = serializers.BooleanField(required=False)
    language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default='python')
    style = serializers.ChoiceField(choices=STYLE_CHOICES, default='friendly')

    def create(self, validated_data):
        """
        Create and return a new `Snippet` instance, given the validated data.
        """
        return Snippet.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        Update and return an existing `Snippet` instance, given the validated data.
        """
        instance.title = validated_data.get('title', instance.title)
        instance.code = validated_data.get('code', instance.code)
        instance.linenos = validated_data.get('linenos', instance.linenos)
        instance.language = validated_data.get('language', instance.language)
        instance.style = validated_data.get('style', instance.style)
        instance.save()
        return instance

注：就像django里的Form和ModelForm一样，序列化也有Serializer和ModelSerializer

#!/usr/bin/env python
# coding:utf-8
from __future__ import absolute_import, print_function, division
from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES

#已实现create和update
class SnippetSerializer(serializers.ModelSerializer):
    class Meta:
        model = Snippet
        fields = ("id", "title", "code", "linenos", "language", "style")

In [1]: from snippets.serializers import  SnippetSerializer

In [2]: serializer = SnippetSerializer()

In [3]: print(repr(serializer))
SnippetSerializer():
    id = IntegerField(label='ID', read_only=True)
    title = CharField(allow_blank=True, max_length=100, required=False)
    code = CharField(style={'base_template': 'textarea.html'})
    linenos = BooleanField(required=False)
    language = ChoiceField(choices=[('abap', 'ABAP'), ('abnf', 'ABNF'), ('ada', 'Ada'), ...], required=False)
    style = ChoiceField(choices=[('abap', 'abap'), ..., ('xcode', 'xcode')], required=False)

五、视图

编辑snippets/views.py

# -*- coding: utf-8 -*-
from __future__ import unicode_literals
# Create your views here.

from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.renderers import JSONRenderer
from rest_framework.parsers import JSONParser
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer

@csrf_exempt
def snippet_list(request):
    """
    List all code snippets, or create a new snippet.
    """
    if request.method == 'GET':
        snippets = Snippet.objects.all()
        serializer = SnippetSerializer(snippets, many=True)
        return JsonResponse(serializer.data, safe=False)

    elif request.method == 'POST':
        data = JSONParser().parse(request)
        serializer = SnippetSerializer(data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data, status=201)
        return JsonResponse(serializer.errors, status=400)

@csrf_exempt
def snippet_detail(request, pk):
    """
    Retrieve, update or delete a code snippet.
    """
    try:
        snippet = Snippet.objects.get(pk=pk)
    except Snippet.DoesNotExist:
        return HttpResponse(status=404)

    if request.method == 'GET':
        serializer = SnippetSerializer(snippet)
        return JsonResponse(serializer.data)

    elif request.method == 'PUT':
        data = JSONParser().parse(request)
        serializer = SnippetSerializer(snippet, data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data)
        return JsonResponse(serializer.errors, status=400)

    elif request.method == 'DELETE':
        snippet.delete()
        return HttpResponse(status=204)

六、路由

创建app路由

新建文件snippets/urls.py

#!/usr/bin/env python
# coding:utf-8
from __future__ import absolute_import, print_function, division
from django.conf.urls import url
from snippets import views

urlpatterns = [
    url(r'^snippets/$', views.snippet_list),
    url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
]

编辑项目路由(tutorial/urls.py)

"""rest_demo URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url, include
from django.contrib import admin

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^', include('snippets.urls')),
]

七、插入数据

python manage.py shell

In [1]: from snippets.models import  Snippet

In [2]: from snippets.serializers import  SnippetSerializer

In [3]: from rest_framework.renderers import  JSONRenderer

In [4]: from rest_framework.parsers import  JSONParser

In [5]: snippet = Snippet(code='foo = "bar"
')

In [6]: snippet.save()

In [7]: snippet = Snippet(code='print "Hello, Django-restframework"
')

In [8]: snippet.save()

In [9]: serializer = SnippetSerializer(snippet)

In [10]: serializer.data
Out[10]:
ReturnDict([('id', 2),
            ('title', u''),
            ('code', u'print "Hello, Django-restframework"
'),
            ('linenos', False),
            ('language', 'python'),
            ('style', 'friendly')])

In [11]: content = JSONRenderer().render(serializer.data)

In [12]: content
Out[12]: '{"id":2,"title":"","code":"print \"Hello, Django-restframework\"\n"
,"linenos":false,"language":"python","style":"friendly"}'

八、测试-httpie

# http http://127.0.0.1:8000/snippets/
HTTP/1.0 200 OK
Content-Length: 248
Content-Type: application/json
Date: Thu, 17 Aug 2017 15:00:56 GMT
Server: WSGIServer/0.1 Python/2.7.12
X-Frame-Options: SAMEORIGIN

[
    {
        "code": "foo = "bar"
",
        "id": 1,
        "language": "python",
        "linenos": false,
        "style": "friendly",
        "title": ""
    },
    {
        "code": "print "Hello, Django-restframework"
",
        "id": 2,
        "language": "python",
        "linenos": false,
        "style": "friendly",
        "title": ""
    }
]

浏览器访问http://127.0.0.1:8000/snippets/

[{"id": 1, "title": "", "code": "foo = "bar"
", "linenos": false, "language": "python", "style": "friendly"}, {"id": 2, "title": "", "code": "print "Hello, Django-restframework"
", "linenos": false, "language": "python", "style": "friendly"}]