Learning JWT Part 3 - Setup controllers, model and signup first user
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###### tags: `JWT`

### MVC - Controllers

Why do we need a controller? It Contains logic that updates the model and/or view in response to input from the users of the app and the core of receiving request/response.

Before we seperate our callback function from router, it would like code below.

const { Router } = require("express");
const router = Router();

// Create routes here
router.get("/signup", (req, res) => {...});
router.post("/signup", (req, res) => {...});
router.get("/login", (req, res) => {...});
router.post("/login", (req, res) => {...});

module.exports = router;

Let's create a folder called **controllers**, inside folder, create a file called **authControllers.js**, migrate callback functions from **authRoutes.js** to here, then we can import them in **authRoutes.js**

// authControllers.js

module.exports.signp_get = (req, res) => {
    res.render("signup");
}

module.exports.login_get = (req, res) => {
    res.render("login");
}

module.exports.signp_get = (req, res) => {
    res.render("signup");
}

module.exports.signup_post = (req, res) => {
    res.render("Create a user");
}

module.exports.login_post = (req, res) => {
    res.render("Login a user");
}

Import these controllers.

// authRoutes.js

const { Router } = require("express");
const authController = require("../controllers/authController");
const router = Router();

// Create routes here
// Since we import authController, after typing authController with dot notation, 
// you can see the controllers list out automatically we have defined earlier.

router.get("/signup", authController.signup_get);
router.post("/signup", authController.signup_post);
router.get("/login", authController.login_get);
router.post("/login", authController.login_post);

module.exports = router;


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### MVC - Model
The model defines what data the app should contain. For example, in this small project, we will need to store user data in MongoDB, so let's create a **User** model.

Here we use [mongoose](https://mongoosejs.com/docs/guide.html) to connect MongoDB.

#### Mongoose core concept
- **Schema**: Each schema maps to a MongoDB collection and defines the shape of the documents within that collection.
- i.e. An **Users** collection in MongoDB.
- We need to define what kind of information (data) that we want to store in **Users** collection.
- Below we have created a schema that describe the shape of the documents **(User)** within the collection **(Users)**

// User.js

const mongoose = require("mongoose");

const userSchema = new mongoose.Schema({
  email: {
    type: String,
    required: true,
    unique: true,
    lowercase: true,
  },
  password: {
    type: String,
    required: true,
    minlength: 6
  }
});

// Define an user model with this mongoose instance
const User = mongoose.model("user", userSchema);

> [Mongoose.prototype.model()](https://mongoosejs.com/docs/api.html#mongoose_Mongoose-model)

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### Create first user

Here we are going to use **User** schema to simulate signing up.

First of all, we need to change code in **authController.js**

const User = require("../models/User");

module.export.signp_post = async (req, res) => {
    // The format would be application/json
    const { email, password } = req.body;
    
    try {
        // Properties passed here must be matched in the User schema
        const user = await User.create({ email, password });
        res.status(201).json(user);
    } catch(error) {
        console.log(error);
        res.status(400).json("Failed to create an user")
    }
}

Let's test by using [Postman](https://www.postman.com/).

- Click **+** to create a new request.
- Select **Post**
- Enter URL: **http://localhost:3000/signup** (Replace port if you'r node is not listening to 3000).
- Select **Body**, **raw** and select **JSON**.

{
    "email": "[e-mail]",
    "password": "123456"
}

Send the request, then you should be able to see the result.


Go to MongoDB to check if user data has sent to DB.


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