无法通过 Express Js Router 请求和响应 Class 方法

Question

I have a problem when creating express JS router.

I can not passing req and res to my class method.

Not Work app.get('/', controller.index)

Work app.get('/', (res,req) => controller.index(req,res)

The following is the flow of the routing that I made:
app.js (Main file) > /routes/index.js > /routes/user.route.js > /controllers/user.controller.js > /services/user.services.js

app.js

import express from 'express';
import cors from 'cors';
import routes from './routes';
import db from './models';
import dotenv from 'dotenv';

dotenv.config();
const app = express();
const port = process.env.PORT || 3001;

app.use(cors())
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

// Database Initialize
db.sequelize.sync()
.then(() => {
    console.log("🚀 Database Connected.");
}).catch((err) => {
    console.log("❌ Failed Connect to Database");
})

// Router
app.use(routes);

//global dir
global.__basedir = __dirname;

app.enable("trust proxy");

app.listen(port, () => {
  // logger.info("Checking the API status: Everything is OK");
  console.log(`🚀 App listening on port ${port}`);
})

routes/index.js

import express from "express";
import appRoutes from './app.routes';
import roleRoutes from './role.routes';
import userRoutes from './user.routes';
import authRoutes from './auth.routes';

const app = express();

// App Routes
app.use('/app', appRoutes);
// Role Routes
app.use('/role', roleRoutes);
// User Routes
app.use('/user', userRoutes);
// Auth Routes
app.use('/auth', authRoutes);

export default app;

routes/user.routes.js

import express from 'express';
import userController from '../controllers/user.controller';
import validateAuth from '../middlewares/validateAuth';

const app = express();
const controller = new userController;

app.get('/', controller.index);

export default app;

controllers/user.controller.js

import userServices from "../services/user.services";
import baseController from "./base.controller";

export default class userController extends baseController {
    constructor() {
        super(new userServices());
    }
}

controllers/base.controller.js

import response from "../helpers/response";
import lang from "../helpers/lang";
import dotenv from "dotenv";
dotenv.config();

export default class baseController {
    constructor(service) {
        this.service = service
    }

    /**
     * Index
     * Get all data with pagination
     */
    async index(res, req) {
        try {
            const data = await this.service.paginate(req.query);
            if(data) {
                return response.success({
                    res,
                    message: lang[process.env.LANG].DATA_LOADED,
                    data
                });
            } else {
                throw new Error(lang[process.env.LANG].REQUEST_FAILED);
            }
        } catch(err) {
            console.log(err)
            return response.error({
                res,
                message: err.message,
            });
        }
    }
}

services/user.services.js

import baseServices from "./base.services";
import db from "../models";

export default class userServices extends baseServices {
    constructor() {
        const attributes = [
            "roleId",
            "appId",
            "username",
            "password",
            "name",
            "phone",
            "email",
            "isActive",
        ];
        super(db.user, attributes);
    }

    /**
     * Paginate
     * @param {{
     *  search: string,
     *  limit: number,
     *  offset: number,
     *  sortBy: string,
     *  orderBy: string,
     *  user: object
     * }} data
     * return Promise
     */
    paginate(data) {
        const { search, limit, page, sortBy, orderBy, user } = data;

        const offset = limit
            ? parseInt(limit) * parseInt(page) - parseInt(limit)
            : 0;

        let filter = {};
        if (search)
            Object.assign(filter, { name: { [Op.like]: `%${search}%` } });

        const condition = {
            where: filter ? filter : "",
            order: sortBy ? [[sortBy, orderBy]] : [["name", "asc"]],
            limit: limit ? parseInt(limit) : 10,
            offset,
            include: ["role", "app"]
        };

        return this.model.findAndCountAll(condition);
    }
}

services/base.services.js

import db from "../models";
const Op = db.Sequelize.Op;

/**
 * Base Services Class
 */
export default class baseServices {
    constructor(model, attributes = []) {
        this.model = model;
        this.attributes = attributes
    }
}

Response

Not Work app.get('/', controller.index)
Error Response

Work app.get('/', (res,req) => controller.index(req,res)

Success Response

I was try to change const app = express() and const app = express.Router() but still have the same problem.

Answer 1

I see two things wrong here:

1. You are losing the controller object in the index method because of the way you're passing the index method.

2. You are doing some very confusing things with the order of the (req, res) arguments.

Your controller.index() method declares them in reverse as:

async index(res, req) { ... }

So, that's why:

app.get('/', controller.index)

doesn't work. Because the arguments are passed as (req, res) by Express, but your method expects them as (res, req) .

Then, the reason that this works:

app.get('/', (res,req) => controller.index(req,res));

is because you reverse the argument again.

---

So, change the method to this:

async index(req, res) { ... }

so, it matches the way Express passes the arguments and then the arguments will be correct.

Then, because your controller object has instance data and the index method uses this , you also need to make sure the index method is getting passed it's instance properly in this by changing to this:

app.get('/', controller.index.bind(controller));

Answer 2

You should follow the correct MVC pattern and repeat after me, your app.js should be:

require ('dotenv').config();
const routes =  require('./routes');
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
const cors = require('cors');
const db = require('./models');

const port = process.env.PORT || 3001;

app.use(cors());
app.use(express.json());

// Database Initialize
db.sequelize.sync()
.then(() => {
    console.log("🚀 Database Connected.");
}).catch((err) => {
    console.log("❌ Failed Connect to Database");
})

// Router
app.use(routes);

//global dir
global.__basedir = __dirname;

app.enable("trust proxy");

app.listen(port, () => {
  // logger.info("Checking the API status: Everything is OK");
  console.log(`🚀 App listening on port ${port}`);
})

The routes/index.js file should follow the structure:

const router = require("express").Router();

router.use('/app', require(./app.routes"));
router.use('/role', require("./role.routes"));
router.use('/user', require("./user.routes"));
router.use('/auth', require("./auth.routes"));


module.exports = router;

Your all routes file should be like this

user.routes

const userController = require("whatever the location");
const router = require("express").Router();

router.post("/example", userController.controller);

module.exports = router;

The userController file:

const userServices = require("what ever the location");

const controller = async (request, response) => {
    try {
        //code goes here
        await userServices.addUser(
        {
                "name": "ALI",
                "gender": "MALE",
        }
    )
    } catch (error) {
        console.log(error);
        response.status(500).json({
            error: "Something went wrong",
        });
    }
}

module.exports = {
    controller
}

And finally the userServices file is:

const user = require("what ever the location");

const addUser = async (data) => {

    return new Promise((resolve, reject) => {
        new user(data)
            .save()
            .then((data) => resolve(data))
            .catch((err) => reject(err));
    });

}

module.exports = {
    addUser
}