21. Blog接口开发

一般的系统由登录、增删改查所组成。我们的Blog同样如此。我们会开发登录、创建博客、删除博客、修改博客、查询博客等功能。话不多说，我们直接展开实践吧。

思路分析

创建项目。既然我们要创建一个blog，那么我们第一步肯定是创建一个django项目。
创建应用。我们上面已经学过，应用是放在django项目中的。
设计数据库。我们之前提到过MTV设计模式，其中M我们没有用到。但是在Blog系统中我们将会用到。因为我们会创建博客，所以会有数据存储。
编写视图函数V。
配置URL。

代码实现

1.创建项目 django-admin blog

2.创建应用 django-admin startproject article，2.blog/settings.py添加article应用，如下代码所示：

INSTALLED_APPS = [

    'django.contrib.admin',

    'django.contrib.auth',

    'django.contrib.contenttypes',

    'django.contrib.sessions',

    'django.contrib.messages',

    'django.contrib.staticfiles',

    'article',

]

3.设计数据库在article/modles.py输入如下代码：

from django.db import models

# Create your models here.

class Article(models.Model):

    title = models.CharField(max_length=10, )

    author = models.CharField(max_length=10)

    content = models.CharField(max_length=500)

date_publish = models.DateTimeField(auto_now=True)

def __str__(self):

    return self.title

备注：__str__的作用是美化打印出来的结果，使人类更方便查看。

4.新建blog数据库打开wampserver、Navicat，新建blog数据库

5.连接本地数据库因为我们要使用Navicat连接数据库，所以我们需要对我们的项目进行一些修改，打开settings.py文件，注释粗体部分代码，添加数据库配置代码，如下所示：

# Database

# https://docs.djangoproject.com/en/2.1/ref/settings/#databases

# DATABASES = {

#     'default': {

#         'ENGINE': 'django.db.backends.sqlite3',

#         'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),

#     }

# }

# 新增代码

DATABASES = {

    'default':{

        'ENGINE': 'django.db.backends.mysql',

        'HOST': '127.0.0.1',

        'PORT': '3306',

        'NAME': 'blog',

        'USER': 'root',

        'PASSWORD': '',

        'OPTIONS': {

            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",

        },

    }

}

6.在.../blog/init.py 目录下添加：

import pymysql

pymysql.install_as_MySQLdb()

7.数据库迁移执行python manage.py makemigrations，再执行python manage.py migrate

python manage.py makemigrations

python manage.py migrate

8.创建用户。因为我们接口实现登录的功能，所以我们需要创建用户。

F:\新建文件夹\blog>python3 manage.py createsuperuser

Username (leave blank to use 'administrator'): admin

Email address: admin@qq.com

Password:

Password (again):

Superuser created successfully.

9.编写视图函数V，打开article/views.py，输入如下代码

from django.http import JsonResponse

from .models import Article

from django.contrib import auth

# 登录接口

def login(request):

    if request.method == 'POST':

        username = request.POST.get('username', '')

        password = request.POST.get('password', '')

        if username == '' or password == '':

            return JsonResponse({'status': 0, 'message': 'username or password null'})

        user = auth.authenticate(username=username, password=password)

        if user is not None:

            return JsonResponse({'status': 1, 'message': 'login success'})

        else:

            return JsonResponse({'status': 0, 'message': 'username or password error'})

    else:

        return JsonResponse({'status': 0, 'message': 'request type error'})

# 添加文章接口

def add_article(request):

    if request.method == 'POST':

        id = request.POST.get('id', '')

        title = request.POST.get('title', '')

        author = request.POST.get('author', '')

        content = request.POST.get('content', '')

        if id == '' or title == '' or author == '' or content == '':

            return JsonResponse({'status': 0, 'message': 'id or title or author or content null'})

        if len(title) > 10:

            return JsonResponse({'status': 0, 'message': '文章标题过长'})

        if len(author) > 10:

            return JsonResponse({'status': 0, 'message': '作者名称过长'})

        if len(content) > 500:

            return JsonResponse({'status': 0, 'message': '文章内容过长'})

        try:

            result = Article.objects.filter(id=id)

        except ValueError:

            return JsonResponse({'status': 0, 'message': "参数类型错误"})

        if result:

            return JsonResponse({'status': 0, 'message': 'article id already exists'})

        else:

            try:

                Article.objects.create(id=id, title=title, author=author, content=content)

            except BaseException as e:

                return JsonResponse({'status': 0, 'message': e})

            finally:

                data = {

                    "id": id,

                    "title": title,

                    "author": author,

                    "content": content

                }

                return JsonResponse({'status': 1, 'data': data, 'message': 'add article success'})

    else:

        return JsonResponse({'status': 0, 'message': 'request type error'})

# 修改文章接口

def modify_article(request):

    if request.method == 'POST':

        id = request.POST.get('id', '')

        title = request.POST.get('title', '')

        author = request.POST.get('author', '')

        content = request.POST.get('content', '')

        if id == '' or title == '' or author == '' or content == '':

            return JsonResponse({'status': 0, 'message': 'id or title or author or content null'})

        try:

            result = Article.objects.filter(id=id)

        except ValueError:

            return JsonResponse({'status': 0, 'message': "参数类型错误"})

        if not result:

            return JsonResponse({'status': 0, 'message': 'article not exist'})

        if len(title) > 10:

            return JsonResponse({'status': 0, 'message': '文章标题过长'})

        if len(author) > 10:

            return JsonResponse({'status': 0, 'message': '作者名称过长'})

        if len(content) > 500:

            return JsonResponse({'status': 0, 'message': '文章内容过长'})

        try:

            Article.objects.filter(id=id).update(id=id, title=title, author=author, content=content)

        except BaseException as e:

            return JsonResponse({'status': 0, 'message': e})

        finally:

            data = {

                "id": id,

                "title": title,

                "author": author,

                "content": content

            }

            return JsonResponse({'status': 1, 'data': data, 'message': 'modify article success'})

    else:

        return JsonResponse({'status': 0, 'message': 'request type error'})

# 删除文章接口

def delete_article(request):

    if request.method == 'POST':

        id = request.POST.get('id', '')

        if id == '':

            return JsonResponse({'status': 0, 'message': 'id null'})

        try:

            result = Article.objects.filter(id=id)

        except ValueError:

            return JsonResponse({'status': 0, 'message': "参数类型错误"})

        if not result:

            return JsonResponse({'status': 0, 'message': 'id not exist'})

        try:

            Article.objects.filter(id=id).delete()

        except BaseException:

            return JsonResponse({'status': 0, 'message': '删除文章失败'})

        finally:

            return JsonResponse({'status': 1, 'message': 'delete article success'})

    else:

        return JsonResponse({'status': 0, 'message': 'request type error'})

# 查询文章接口

def get_article(request):

    if request.method == 'POST':

        title = request.POST.get("title", "")

        if title == '':

            data = []

            articles = Article.objects.all()

            if articles:

                for article in articles:

                    r = {

                        "id": article.id,

                        "title": article.title,

                        "author": article.author,

                        "content": article.content

                    }

                    data.append(r)

                return JsonResponse({'status': 1, 'message': 'success', 'data': data})

        if title != '':

            data = []

            articles = Article.objects.filter(title__contains=title)

            if articles:

                for article in articles:

                    r = {

                        "id": article.id,

                        "title": article.title,

                        "author": article.author,

                        "content": article.content

                    }

                    data.append(r)

                return JsonResponse({'status': 1, 'message': 'success', 'data': data})

            else:

                return JsonResponse({'status': 0, 'message': 'query result is empty'})

    else:

        return JsonResponse({'status': 0, 'message': 'request type error'})

10.配置URL 打开blog/urls.py输入如下代码

from django.contrib import admin

from django.urls import path

from article import views

urlpatterns = [

    path('admin/', admin.site.urls),

    path('add_article', views.add_article),

    path('modify_article', views.modify_article),

    path('delete_article', views.delete_article),

    path('get_article', views.get_article),

    path('login', views.login),

]

11.启动blog 在manage.py同级目录，输入python manage.py runserver

F:\新建文件夹\blog>python manage.py runserver

Performing system checks...

System check identified no issues (0 silenced).

March 04, 2019 - 13:25:31

Django version 2.1.4, using settings 'blog.settings'

Starting development server at http://127.0.0.1:8000/

Quit the server with CTRL-BREAK.