Node-learn
Table of contents
- Status code
- Node js intallation instructions
- npm instuction for initialize project
- MongoDb intallation instructions
- Node js express mongodb restful crud api
- Jwt token for login
- Folder traverse
- Data pass from ui to server
- Json stringify
- Undefined type checking
- Passing Multiple route params
- Install specific version of package
Status code
// return from node js server
return res.status(403).json("Username incorrect");
return res.status(403).json('token': token, 'msg': "Username incorrect");
// check on mobile font-end
if(response.StatusCode == 200)
print(response.body);
// check on web font-end
console.log("status code: "+response.status);
// codes are
Informational responses ( 100 – 199 )
Successful responses ( 200 – 299 )
Redirects ( 300 – 399 )
Client errors ( 400 – 499 )
Server errors ( 500 – 599 )
// collect from project
500 -> Error in retrieving data
403 -> Password is incorrect / username is incorrect / save not ok / 404 not found
200-> Save ok / 200 0k / success / 201 Added
Node js intallation instructions
npm instuction for initialize project
Tutorial link: https://www.callicoder.com/node-js-express-mongodb-restful-crud-api-tutorial/
- To initial a project and install package.json command
npm init
- To install dependence command
npm i express mongoose ejs
- To install dependence as developent purpose command
npm i --save-dev nodemon detenv
- A dependence uninstall command
npm uninstall body-parser
- node server.js == npm run start / npm start
"scripts": {
"start": "server.js"
//"start": "nodemon server.js"
},
- server.js
const express = require('express');
// create express appCodeName
const app = express();
// parse requests of content-type - application/x-www-form-urlencoded. important for get data in server, when form data post from ejs page.
app.use(express.urlencoded({ extended: true }));
// parse requests of content-type - application/json
app.use(express.json());
// define a simple route
app.get('/', (req, res) => {
res.json({"message": "Welcome to Web Page with nodemon"});
});
// require person routes
const personRoute = require('./jwt/person.routes');
app.use('/jwt', personRoute);
// listen for requests
app.listen(3000, () => {
console.log("Server is listening on port 3000");
});
When use mongoose
// configuring the database
// const dbConfig = require('./config/database.config');
const url= "mongodb://localhost:27017/template"
const mongoose = require('mongoose');
// Connecting to the database
mongoose.connect(dbConfig.url, {
useNewUrlParser: true,
useUnifiedTopology: true,
useFindAndModify: false
}).then(() => {
console.log("Successfully connected to the database");
}).catch(err => {
console.log('Could not connect to the database. Exiting now...', err);
process.exit();
});
- person.routes.js
const express = require('express');
const router = express.Router();
const User = require('../models/user.model');
//home page
router.get('/home', (req, res) => {
res.send('Now we are in Jwt home page.');
});
//get all user
router.get('/allUsers', (req,res) => {
User.find()
.then(users => {
res.send(users);
}).catch(err => {
res.status(500).send({
message: err.message || "some error occurred while rettieving users."
});
});
});
MongoDb intallation instructions
Model demo
const mongoose = require('mongoose');
const PersonSchema = mongoose.Schema({
name: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
email: {
type: String,
required: true
}
}, {
timestamps: true
});
module.exports = mongoose.model('Person', PersonSchema);
For designing mongoose model, different types of attributes
title: String
comments: [{body: String, date: Date}],
date: {type: Date, default: Date.now},
hidden: Boolean,
meta: {
votes: Number,
favs: Number
},
// for auto populate timestamps, install mongoose-autopopulate package, then add below code
,{timestamps: ture}).plugin(require('mongoose-autopopulate'));
age: {type:number, min: 18, max: 65}
stuff: {type: String, lowercase: true, trim: true}
unique: true, sparse: true, default: null, default:''
userType: {type: String, enum: ['user', 'admin'], default: 'user']}
Node js express mongodb restful crud api
Jwt token for login
npm install jsonwebtoken
// secret key
module.exports={
key:"JwtLoginApp"
}
// middleware to check user/token is validate or note
const jwt = require('jsonwebtoken');
const config = require('./config');
const checkToken = (req, res, next) => {
let token = req.headers["authorization"];
console.log(token);
token = token.slice(7, token.length);
if (token){
jwt.verify(token, config.key, (err, decoded) => {
if (err){
return res.json({
status: false,
msg: "token is invalid"
});
}
else {
req.decoded = decoded;
next();
}
});
} else {
return res.json({
status: false,
msg: "Token is not provided",
});
}
};
module.exports = {
checkToken: checkToken
};
// in router
const config = require('./config');
const jwt = require('jsonwebtoken');
const middleware = require('./middleware');
// login person
router.post("/login", async (req, res) => {
Person.findOne({name: req.body.name}, (err, result) => {
if(err) return res.status(500).json({msg: err});
if(result == null) {
return res.status(403).json("Username incorrect");
}
if (result.password === req.body.password){
// implementation of jwt token functionality
let token = jwt.sign({name: req.body.name}, config.key, {
expiresIn: "24h",
});
res.send({
token: token,
msg: "Success",
});
} else {
res.status(403).json("password is incorrect");
}
});
});
// now using in router to check the token
router.put("/update/:name", middleware.checkToken, async (req, res) => {});
Folder traverse
// root
// - server.js
// - routes
// - user.routes.js
// - controllers
// - user.controller.js
require('./routes/user.routes')(app); // write this in server.js file
require("../controllers/user.controller"); // write this in user.routes.js file
Data pass from ui to server
// when data send by body
app.post('/users', (req, res) => name: req.body.name )
// when data send by url parameter
app.put('/users/:userId, (req, res) => name: req.params.userId )
- Server
// status code send to client
return res.status(500).json({ msg: err });
// pass data to client
return res.json({
data: result,
username: req.params.username,
});
// data received by body from client
const user = new User({
username: req.body.username,
password: req.body.password,
email: req.body.email,
});
// data received by parameter from client
router.route("/delete/:username").delete(
username: req.params.username,
)
// token get from headers
let token = req.get('Authorization');
- Client: Mobile
// get statusCode & data from server
var response = await http.get(
url,
headers: {"Authorization": "Bearer $token"},
);
if (response.statusCode == 200 || response.statusCode == 201) { // status code
log.i(response.body);
return json.decode(response.body); // data
}
// pass data to server
1.
Map<String, String> data = {
"username": _usernameController.text,
"password": _passwordController.text,
};
var response =
await networkHandler.post("/user/login", data);
if (response.statusCode == 200 || response.statusCode == 201) {
Map<String, dynamic> output = json.decode(response.body);
print(output["token"]);
}
2.
var response = await http.post(
url,
headers: {
"Content-type": "application/json",
"Authorization": "Bearer $token"
},
body: json.encode(body),
);
return response;
// patch requests
var response = await http.patch(
url,
headers: {
"Content-type": "application/json",
"Authorization": "Bearer $token"
},
body: json.encode(body),
);
- Client: web
fetch(`/user/task/${todo._id}`,{
method : "put",
headers : {
"Content-Type" : "application/json; charset=utf-8"
},
body : JSON.stringify({task : taskUserInput.val()})
}).then((response)=>{
console.log(response); // here you can check status code
return response.json();
}).then((data)=>{
console.log(data.task);
console.log(data.createdAt);
});
Json stringify
- json data convert to string to sent data to server
const obj = {name: "John", age: 30, city: "New York"};
const myJSON = JSON.stringify(obj); // {"name":"John","age":30,"city":"New York"}
Undefined type checking
if(typeof token === 'undefined'){
res.redirect('/user/login');
return;
}
Passing multiple route params
// passing two params with link
http://localhost:3000/user/home/no/name
// route
router.get('/home/:active/:name', multiParamsRoute);
// getting value in routes
req.params.active
req.params.name
Install specific version of package
npm install mongoose@6.0.4
- TextField undefined error removed by installing 5.9.17 version of mongoose
npm install mongoose@5.9.17
Multer for upload image
- install
npm install multer
- model (Upload.model.js)
const mongoose=require('mongoose');
const UploadSchema=mongoose.Schema({
name: {
type: String,
required: true
},
img: {
type: String,
default: "",
},
});
module.exports=mongoose.model('Upload',UploadSchema);
- routes (upload.routes.js)
const express = require('express');
const router = express.Router();
const Upload = require('../models/Upload');
const multer = require("multer");
const path = require("path");
const storage = multer.diskStorage({
destination: (req, file, cb) => {
cb(null, "./uploads");
},
filename: (req, file, cb) => {
cb(null, Date.now() + ".jpg");
},
});
const fileFilter = (req, file, cb) => {
if (file.mimetype == "image/jpeg" || file.mimetype == "image/png") {
cb(null, true);
}
};
const upload = multer({
storage: storage,
limits: {
fileSize: 1024 * 1024 * 6,
},
fileFilter: fileFilter,
});
router.post('/add', (req, res) => {
const upload = new Upload({
name: req.body.name
});
try {
const savedUpload = upload.save();
res.json(savedUpload);
} catch (error) {
res.json({ message: error });
}
});
router.get('/getall', async (req, res) => {
try {
const uploads = await Upload.find();
res.json(uploads);
} catch (error) {
res.json({ message: error });
}
// res.send('We are on users home');
});
router.patch("/add/image/:id", upload.single("img"), (req, res) => {
Upload.findOneAndUpdate(
{ _id: req.params.id },
{
$set: {
img: req.file.path,
},
},
{ new: true },
(err, upload) => {
if (err) return res.status(500).send(err);
const response = {
message: "image added successfully updated",
data: upload,
};
return res.status(200).send(response);
}
);
});
module.exports = router;
- app.js
const express = require('express');
const app = express();
const mongoose = require('mongoose');
const usersRoute = require('./routes/users');
const uploadRoute = require('./routes/upload');
const DB_CONNECTION_URL=mongodb://localhost:27017/userDB;
//mongoose
mongoose.connect(DB_CONNECTION_URL, { useNewUrlParser: true, useUnifiedTopology: true, useFindAndModify: false }, function (err, db) {
if (err) throw err;
else console.log('Connected to DB');
});
// to show the image in web browser from uploads folder by uploaded path
app.use('/uploads', express.static("uploads"));
//middleware
app.use(express.json());
//import routes
app.use('/users', usersRoute);
app.use('/upload', uploadRoute);
//routes
app.get('/', (req, res) => {
console.log('We are on Home');
res.send('We are on Home');
});
app.listen(3000);
- packages
"body-parser": "^1.19.0",
"dotenv": "^8.2.0",
"express": "^4.17.1",
"mongoose": "^5.9.17",
"multer": "^1.4.3",
"nodemon": "^2.0.2"