A simple Node application development process

Now that I’ve had the time to learn more about Node, what do you want to make? After thinking about it, let’s make a simple bolg. Next, I will introduce the specific process.

Technology stack

• node
• Express (Web Application Framework)
• Mongoose (Database)
• Pm2 (Application Process Management)
• Swagger (API function debugging)

Project introduction

This article will introduce Node-app with specific items: github.com/Hancoson/no…

File structure

• App.js: entry file
• Package. json: Project information and package management
• Node_moudules: dependency module
• Public: static resources (CSS, JS, images)
• Routes: routes management
• View: template file
• Models: Data model
• Config: indicates the project configuration file
• App: store controllers, common methods, etc
• Bin: project configuration script

The MVC pattern

• Model
  • nodeProvides modules, middleware, in useexpressGenerated when the project is creatednode_modulesIt indicates that theMlayer
  • Modules such asejs.mongoose.morgan.body-parser, etc.
• View
  • expressGenerated when the project is generatedviews, that is, the front
• Controller
  • That is, the view sends a request to the controller, and the controller selects the corresponding model to process it
  • The model returns the results to the controller, which selects the appropriate view and generates an interface for the user
  • Such as throughres.renderTo renderejsfile

routing

• Meaning: Called when visiting the home pageejsTemplate engine renderingindex.ejsfile
• Implementation method:
  • inapp.jswritesrequire('./routes/index')(app)Can be introduced;
  • The corresponding route is imported in the routeControllerTo achieve the display of specific dataapp.get('/articles/:id', articles.getArticle);

Controller

It mainly deals with business logic, that is, how data should be displayed is managed by him. The specific implementation is as follows:

function(req, res) {blogdbs.find({_id: req.params.id // query condition},function (err, data) {
    if (err) {
      //err
    } else {
      res.render('articles', {... // Data object}); }})}Copy the code

Model

Let’s talk about Schema before we talk about Model, but what is Schema? It is similar to the table structure of a relational database. The concrete implementation is as follows:

var mongoose = require('mongoose');
var schema = mongoose.Schema;
var _blogSchema = new Schema({
  title: {
    type: 'String'},... });Copy the code

Model (modelName, schema);

Why have a Model when you have a Schema?

In Mongoose’s design concept, Schema only defines data structures, and the specific operations of adding, deleting, modifying and checking data are performed by Model.

It’s like Foxconn building a phone out of a mold. When you need to make a call, you use the phone instead of the mold.

Problems encountered

• Node development requires frequent project restarts, which I learned laterpm2To manage the process and monitor itnodeServer update, no need to restart the service, greatly improve the development efficiency.
• When the server commits data asynchronously,app.jsThe following code needs to be added to the route import.

  app.use(bodyParser.json());
  app.use(bodyParser.urlencoded({extended: false}));Copy the code

• App.get (), app.use() and app.all()

  • The callback in app.use(path,callback) can be either a Router object or a function
  • Callback in app.get(path,callback) can only be a function. App.get () can be used as a shorthand for the get method in app.use().
  • App.all () is the route attached to the application, so the app.Router middleware handles all routing requests, such as GET, POST, etc.

  var express = require('express');
  var app = express();
  app.get('/hello'.function(req,res,next){
    res.send('hello test2'); }); Var express = require('express');
  var app = express();
  var router = express.Router();
  router.get('/'.function(req, res, next) {
    res.send('hello world! ');
  });
  app.use('/hello',router);Copy the code

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  Project address: Node-app