nodeJs--encapsulate routing

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I. What is routing

Routing: Refers to different URLs to execute different branches or programs

Second, encapsulating routing

Requirements: Enter the URL at the front end and return the corresponding data at the back end. First enter the URL and then go to the statically hosted folder to find it; if not, go to our data interface, and if not, pass a string such as "404 not found".
**Static hosting:** When the user enters the URL, we can use the middleware in the backend to add a folder at the beginning of the pathname to read in the url of readFile, which is achieved, the user can only accessfiles in that folder.
For example:

var url=require("url")var http=require("http")var fs=require("fs")http.createServer((req,res)=>{let pathname=url.parse(req.url).pathnamefs.readFile(__dirname+'/public'+path,(err,data)=>{ // '/public' is the folder we want to hostres.end(data)}}).listen(8080)

Design idea: According to the needs, the MVC programming idea is used to design.

What is MVC

V stands for View View refers to the interface that the user sees and interacts with.For example, a web interface composed of html elements, or a client interface of a software.One of the benefits of MVC is that it can handle many different views for an application.No real processing happens in the view, it's just a way to output data and allow the user to manipulate it.

M stands for model model, which means that the model represents business rules.Of the three components of MVC, the model has the most processing tasks.The data returned by the model is neutral, and the model has nothing to do with the data format. Such a model can provide data for multiple views. Since the code applied to the model only needs to be written once and can be reused by multiple views, code duplication is reducedsex.

C is the controller controller means that the controller accepts the user's input and calls the model and view to complete the user's needs. The controller itself does not output anything or do any processing.It just receives the request and decides which model component to call to handle the request, and then decides which view to use to display the returned data.

Simply put: M refers to the business model, V refers to the user interface, and C refers to the controller. The purpose of using MVC is to separate the implementation codes of M and V, so that the same program can use different expressions.

Route source code:

Business Model:

var obj={}var fs=require("fs")var url=require("url")var mime=require("mime")var controller=require("./controller.js")var router=function(req,res){let pathname=url.parse(req.url).pathnamelet type=mime.getType(pathname)fs.readFile(router.basename+pathname,(err,data)=>{if(!err){res.setHeader("content-Type",type)res.end(data)}else{if(obj[pathname]){obj[pathname](req,res)}else{res.end("404 not found")}}})}router.basename=__dirname+'/src'router.stacte=function(path){this.basename=path}router.get=function(path,callback){obj[path]=callback}module.exports=router

Controller:

module.exports={ajax1(req,res){var obj={name:'ljy',age:22}var str=JSON.stringify(obj)res.setHeader("content-Type","text/json;charts-utf8")res.end(str)}//Write the data returned by the business function to the front end here}

view interface

var http=require("http")var router=require("./router.js")var constroller=require("./controller.js")http.createServer(router).listen(8081) //Set the server, followed by the port number for setting the listeningrouter.get("/ajax1",constroller.ajax1) //Add data interface, you need to configure the business function of the controllerrouter.stacte(__dirname+'/src') //Set static hosting files