Django利用Channels+websocket开发聊天室

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目录

前言

一、什么是Websocket？

2.Python-Django ASGI

3，Django开发聊天室或信息推送

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前言

数据库系统课程设计要求，要开发一个B2B的售卖平台，本来开发浅薄的我，粗糙又基础的完成了一些基本的功能，想要开发一个单独的一对一聊天的功能(类似于微信这类)，查阅了不少资料，依旧没思路，但是却知晓了服务器推送信息和聊天室的开发，记个笔记。

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提示：以下是本篇文章正文内容，下面案例可供参考

一、什么是Websocket？

1，Websocket的诞生背景：网站为了实现推送技术，用的基本是轮询，轮询是基于浏览器不断对服务器发出HTTP请求，服务器范围最新数据给客户端浏览器，这种模式缺点明显，带宽浪费严重，在这种背景下，HTML5诞生了Websocket协议，能更好的节省服务器资源并实现通讯。

2，WebSocket特点：WebSocket是单个TCP连接上的全双工通信，浏览器和服务器只需要完成一次握手，就可以创建持久性的连接，实现数据的双向传输。

2.Python-Django ASGI

1，WSGI：Python Web Server Gateway Interface，就是Web服务器网关接口，主要是规范了Web服务器和Web应用之间的交互，WSGI将Django分成了三类，服务器，APP，中间件。服务器就是用来监听某端口，APP用来调用某个函数，而中间件则位于两者中间，相当于一道门，起审核承接等作用。但是WSGI始终是为同步世界编写的，无法编写异步对象。因此，ASGI诞生了。

2，ASGI：Async Sever Gateway Interface，说白了，就是相当于WSGI+异步功能，而要调用WebSocket，Django就需要使用ASGI接口。

3，Django开发聊天室或信息推送

第一步：下载Channels模块

pip install channels

第二步：创建Django项目

Django-admin startproject websocket

创建后会看到Django3.0以后自存在asgi.py文件

第三步：创建一个APP应用

python manage.py startapp websocket_demo

第四步：进入settings.py模块，进行配置

首先在INSTALLED_APPS添加channels和websocket_demo

 然后添加再在settings中添加ASGI应用

 第五步：在创建的APP中创建routing.py文件以及进入asgi.py模块进行修改如下：

import os

from django.core.asgi import get_asgi_application
from channels.routing import ProtocolTypeRouter, URLRouter
from websocket_demo import routing

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'web_socket.settings')

application = ProtocolTypeRouter({
    "http": get_asgi_application(),
    "websocket": URLRouter(routing.websocket_urlpatterns),

})

图中代码很容易理解：将服务器的请求分成了两类，http请求则走默认的asgi APP流程，是Websocket请求则进入URL路由，即websocket_demo创建的routing.py文件

第六步，在websocket_demo的APP中views视图下创建chat.py并且配置routing.py的文件：

from django.urls import re_path
from websocket_demo.views import chat

websocket_urlpatterns = [
    re_path(r'chat/(?P\w+)/$', chat.ChatConsumer.as_asgi()),
]

使用正则路径匹配chat/数字/的路径，是则进入chat.py文件中的CharConsumer函数

第七步，在urls.py中配置路由，指向websocket_demo中的chat.py文件

from django.urls import path, include
from websocket_demo.views import chat

urlpatterns = [
    path('index/', chat.chat)
]

第八步，编写chat.py文件的内容如下:

from django.shortcuts import render
from channels.generic.websocket import WebsocketConsumer
from channels.exceptions import StopConsumer
from asgiref.sync import async_to_sync
from datetime import datetime


def chat(request):
    group_number = request.GET.get('num')
    return render(request, 'web/index.html', context)




class ChatConsumer(WebsocketConsumer):

    def websocket_connect(self, message):
        self.accept()
        group = self.scope['url_route']['kwargs'].get("group")
        async_to_sync(self.channel_layer.group_add)(group, self.channel_name)

    def websocket_receive(self, message):
        group = self.scope['url_route']['kwargs'].get("group")
        async_to_sync(self.channel_layer.group_send)(group, {"type": "chat", 'message': message})

    def chat(self, event):
        text = event['message']['text']
        self.send(text)

    def websocket_disconnect(self, message):
        group = self.scope['url_route']['kwargs'].get("group")
        async_to_sync(self.channel_layer.group_discard)(group, self.channel_name)
        print('客户端断开连接了')
        raise StopConsumer()

首先第一个函数的意思是，进入index页面后会先进入chat函数，获取URL中请求的参数num，渲染到index.html页面，然后index.html页面使用javascript发起websocket请求，发起websocket请求后，ASGI服务器通过"websocket": URLRouter(routing.websocket_urlpatterns)路由访问routing文件，routing文件指向了ChatConsumer(WebsocketConsumer)类。

第二个函数ChatConsumer(WebsocketConsumer)类对websocket请求进行了处理，接收websocket的请求后获取组号即num的值，然后接收websocket发送的信息后调用chat函数将收到的信息同等的发送回去，websocket_disconnet则是客户端断开请求后触发的函数。

前端index.html的文件如下：

  reset.min.css文件:

html,body,div,span,applet,object,iframe,h1,h2,h3,h4,h5,h6,p,blockquote,pre,a,abbr,acronym,address,big,cite,code,del,dfn,em,img,ins,kbd,q,s,samp,small,strike,strong,sub,sup,tt,var,b,u,i,center,dl,dt,dd,ol,ul,li,fieldset,form,label,legend,table,caption,tbody,tfoot,thead,tr,th,td,article,aside,canvas,details,embed,figure,figcaption,footer,header,hgroup,menu,nav,output,ruby,section,summary,time,mark,audio,video{margin:0;padding:0;border:0;font-size:100%;font:inherit;vertical-align:baseline}article,aside,details,figcaption,figure,footer,header,hgroup,menu,nav,section{display:block}body{line-height:1}ol,ul{list-style:none}blockquote,q{quotes:none}blockquote:before,blockquote:after,q:before,q:after{content:'';content:none}table{border-collapse:collapse;border-spacing:0}

style.css文件:

        

*, *:before, *:after {
  box-sizing: border-box;
}

:root {
  --white: #fff;
  --black: #000;
  --bg: #f8f8f8;
  --grey: #999;
  --dark: #1a1a1a;
  --light: #e6e6e6;
  --wrapper: 1000px;
  --blue: #00b0ff;
}

body {
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-family: 'Source Sans Pro', sans-serif;
  font-weight: 400;
  background-image: url("../img/image.jpg");
  background-size: cover;
  background-repeat: none;
}

.wrapper {
  position: relative;
  left: 50%;
  width: var(--wrapper);
  height: 800px;
  -webkit-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}

.container {
  position: relative;
  top: 50%;
  left: 50%;
  width: 80%;
  height: 75%;
  background-color: var(--white);
  -webkit-transform: translate(-50%, -50%);
          transform: translate(-50%, -50%);
}
.container .left {
  float: left;
  width: 37.6%;
  height: 100%;
  border: 1px solid var(--light);
  background-color: var(--white);
}
.container .left .top {
  position: relative;
  width: 100%;
  height: 96px;
  padding: 29px;
}
.container .left .top:after {
  position: absolute;
  bottom: 0;
  left: 50%;
  display: block;
  width: 80%;
  height: 1px;
  content: '';
  background-color: var(--light);
  -webkit-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}
.container .left input {
  float: left;
  width: 188px;
  height: 42px;
  padding: 0 15px;
  border: 1px solid var(--light);
  background-color: #eceff1;
  border-radius: 21px;
  font-family: 'Source Sans Pro', sans-serif;
  font-weight: 400;
}
.container .left input:focus {
  outline: none;
}
.container .left a.search {
  display: block;
  float: left;
  width: 42px;
  height: 42px;
  margin-left: 10px;
  border: 1px solid var(--light);
  background-color: var(--blue);
  background-image: url("../img//name-type.png");
  background-repeat: no-repeat;
  background-position: top 12px left 14px;
  border-radius: 50%;
}
.container .left .people {
  margin-left: -1px;
  border-right: 1px solid var(--light);
  border-left: 1px solid var(--light);
  width: calc(100% + 2px);
}
.container .left .people .person {
  position: relative;
  width: 100%;
  padding: 12px 10% 16px;
  cursor: pointer;
  background-color: var(--white);
}
.container .left .people .person:after {
  position: absolute;
  bottom: 0;
  left: 50%;
  display: block;
  width: 80%;
  height: 1px;
  content: '';
  background-color: var(--light);
  -webkit-transform: translate(-50%, 0);
          transform: translate(-50%, 0);
}
.container .left .people .person img {
  float: left;
  width: 40px;
  height: 40px;
  margin-right: 12px;
  border-radius: 50%;
}
.container .left .people .person .name {
  font-size: 14px;
  line-height: 22px;
  color: var(--dark);
  font-family: 'Source Sans Pro', sans-serif;
  font-weight: 600;
}
.container .left .people .person .time {
  font-size: 14px;
  position: absolute;
  top: 16px;
  right: 10%;
  padding: 0 0 5px 5px;
  color: var(--grey);
  background-color: var(--white);
}
.container .left .people .person .preview {
  font-size: 14px;
  display: inline-block;
  overflow: hidden !important;
  width: 70%;
  white-space: nowrap;
  text-overflow: ellipsis;
  color: var(--grey);
}
.container .left .people .person.active, .container .left .people .person:hover {
  margin-top: -1px;
  margin-left: -1px;
  padding-top: 13px;
  border: 0;
  background-color: var(--blue);
  width: calc(100% + 2px);
  padding-left: calc(10% + 1px);
}
.container .left .people .person.active span, .container .left .people .person:hover span {
  color: var(--white);
  background: transparent;
}
.container .left .people .person.active:after, .container .left .people .person:hover:after {
  display: none;
}
.container .right {
  position: relative;
  float: left;
  width: 62.4%;
  height: 100%;
}
.container .right .top {
  width: 100%;
  height: 47px;
  padding: 15px 29px;
  background-color: #eceff1;
}
.container .right .top span {
  font-size: 15px;
  color: var(--grey);
}
.container .right .top span .name {
  color: var(--dark);
  font-family: 'Source Sans Pro', sans-serif;
  font-weight: 600;
}
.container .right .chat {
  position: relative;
  display: none;
  overflow: hidden;
  padding: 0 35px 92px;
  border-width: 1px 1px 1px 0;
  border-style: solid;
  border-color: var(--light);
  height: calc(100% - 48px);
  justify-content: flex-end;
  flex-direction: column;
}
.container .right .chat.active-chat {
  display: block;
  display: flex;
}
.container .right .chat.active-chat .bubble {
  transition-timing-function: cubic-bezier(0.4, -0.04, 1, 1);
}
.container .right .chat.active-chat .bubble:nth-of-type(1) {
  -webkit-animation-duration: 0.15s;
          animation-duration: 0.15s;
}
.container .right .chat.active-chat .bubble:nth-of-type(2) {
  -webkit-animation-duration: 0.3s;
          animation-duration: 0.3s;
}
.container .right .chat.active-chat .bubble:nth-of-type(3) {
  -webkit-animation-duration: 0.45s;
          animation-duration: 0.45s;
}
.container .right .chat.active-chat .bubble:nth-of-type(4) {
  -webkit-animation-duration: 0.6s;
          animation-duration: 0.6s;
}
.container .right .chat.active-chat .bubble:nth-of-type(5) {
  -webkit-animation-duration: 0.75s;
          animation-duration: 0.75s;
}
.container .right .chat.active-chat .bubble:nth-of-type(6) {
  -webkit-animation-duration: 0.9s;
          animation-duration: 0.9s;
}
.container .right .chat.active-chat .bubble:nth-of-type(7) {
  -webkit-animation-duration: 1.05s;
          animation-duration: 1.05s;
}
.container .right .chat.active-chat .bubble:nth-of-type(8) {
  -webkit-animation-duration: 1.2s;
          animation-duration: 1.2s;
}
.container .right .chat.active-chat .bubble:nth-of-type(9) {
  -webkit-animation-duration: 1.35s;
          animation-duration: 1.35s;
}
.container .right .chat.active-chat .bubble:nth-of-type(10) {
  -webkit-animation-duration: 1.5s;
          animation-duration: 1.5s;
}
.container .right .write {
  position: absolute;
  bottom: 29px;
  left: 30px;
  height: 42px;
  padding-left: 8px;
  border: 1px solid var(--light);
  background-color: #eceff1;
  width: calc(100% - 58px);
  border-radius: 5px;
}
.container .right .write input {
  font-size: 16px;
  float: left;
  width: 347px;
  height: 40px;
  padding: 0 10px;
  color: var(--dark);
  border: 0;
  outline: none;
  background-color: #eceff1;
  font-family: 'Source Sans Pro', sans-serif;
  font-weight: 400;
}
.container .right .write .write-link.attach:before {
  display: inline-block;
  float: left;
  width: 20px;
  height: 42px;
  content: '';
  background-image: url("../img/attachment.png");
  background-repeat: no-repeat;
  background-position: center;
}
.container .right .write .write-link.smiley:before {
  display: inline-block;
  float: left;
  width: 20px;
  height: 42px;
  content: '';
  background-image: url("../img/smiley.png");
  background-repeat: no-repeat;
  background-position: center;
}
.container .right .write .write-link.send:before {
  display: inline-block;
  float: left;
  width: 20px;
  height: 42px;
  margin-left: 11px;
  content: '';
  background-image: url("../img/send.png");
  background-repeat: no-repeat;
  background-position: center;
}
.container .right .bubble {
  font-size: 16px;
  position: relative;
  display: inline-block;
  clear: both;
  margin-bottom: 8px;
  padding: 13px 14px;
  vertical-align: top;
  border-radius: 5px;
}
.container .right .bubble:before {
  position: absolute;
  top: 19px;
  display: block;
  width: 8px;
  height: 6px;
  content: '\00a0';
  -webkit-transform: rotate(29deg) skew(-35deg);
          transform: rotate(29deg) skew(-35deg);
}
.container .right .bubble.you {
  float: left;
  color: var(--white);
  background-color: var(--blue);
  align-self: flex-start;
  -webkit-animation-name: slideFromLeft;
          animation-name: slideFromLeft;
}
.container .right .bubble.you:before {
  left: -3px;
  background-color: var(--blue);
}
.container .right .bubble.me {
  float: right;
  color: var(--dark);
  background-color: #eceff1;
  align-self: flex-end;
  -webkit-animation-name: slideFromRight;
          animation-name: slideFromRight;
}
.container .right .bubble.me:before {
  right: -3px;
  background-color: #eceff1;
}
.container .right .conversation-start {
  position: relative;
  width: 100%;
  margin-bottom: 27px;
  text-align: center;
}
.container .right .conversation-start span {
  font-size: 14px;
  display: inline-block;
  color: var(--grey);
}
.container .right .conversation-start span:before, .container .right .conversation-start span:after {
  position: absolute;
  top: 10px;
  display: inline-block;
  width: 30%;
  height: 1px;
  content: '';
  background-color: var(--light);
}
.container .right .conversation-start span:before {
  left: 0;
}
.container .right .conversation-start span:after {
  right: 0;
}

@keyframes slideFromLeft {
  0% {
    margin-left: -200px;
    opacity: 0;
  }
  100% {
    margin-left: 0;
    opacity: 1;
  }
}
@-webkit-keyframes slideFromLeft {
  0% {
    margin-left: -200px;
    opacity: 0;
  }
  100% {
    margin-left: 0;
    opacity: 1;
  }
}
@keyframes slideFromRight {
  0% {
    margin-right: -200px;
    opacity: 0;
  }
  100% {
    margin-right: 0;
    opacity: 1;
  }
}
@-webkit-keyframes slideFromRight {
  0% {
    margin-right: -200px;
    opacity: 0;
  }
  100% {
    margin-right: 0;
    opacity: 1;
  }
}

index.js文件:

                

document.querySelector('.chat[data-chat=person2]').classList.add('active-chat');
document.querySelector('.person[data-chat=person2]').classList.add('active');

var friends = {
  list: document.querySelector('ul.people'),
  all: document.querySelectorAll('.left .person'),
  name: '' },

chat = {
  container: document.querySelector('.container .right'),
  current: null,
  person: null,
  name: document.querySelector('.container .right .top .name') };


friends.all.forEach(function (f) {
  f.addEventListener('mousedown', function () {
    f.classList.contains('active') || setAciveChat(f);
  });
});

function setAciveChat(f) {
  friends.list.querySelector('.active').classList.remove('active');
  f.classList.add('active');
  chat.current = chat.container.querySelector('.active-chat');
  chat.person = f.getAttribute('data-chat');
  chat.current.classList.remove('active-chat');
  chat.container.querySelector('[data-chat="' + chat.person + '"]').classList.add('active-chat');
  friends.name = f.querySelector('.name').innerText;
  chat.name.innerHTML = friends.name;
}

index.html文件:

{% load static from static %}















	

        

            

                
                
            
            

                

                    
                    {{admin_name}}
                    I was wondering...
                
            
        
        

            
To: {{admin_name}}
            

                

                    {{time}}
                
            
            

                
                
                
                
            
        
    

主要看javascript使用的函数，首先进行Websocket请ws://127.0.0.1:8000/chat/{{group_number}}/，然后分别的通过websocket发送信息，接受信息。

第九步，启动manage.py文件，同时打开两个页面观看效果:

        

可以看到，某个用户发送的信息，将会被服务器发送到同一聊天室的所有客户端，实现了信息推送的功能。 

但是要实现一对一聊天的功能，目前实现是没有思路，有大神看到烦请指点指点。