Express Js routing example - GET/POST/PUT

Question: Give example of express JS working with Node?

var express = require('express');
var app = express();

var bodyParser = require('body-parser')
app.use(bodyParser.json());  
app.use(bodyParser.urlencoded({
    extended: true
}));

app.get('/', function(req, res){
  res.send('id: ' + req.query.id);  
});
app.listen(3000);

Question: What is use of body-parser?
It is middleware in nodeJS.
body-parser is used to parse incoming request bodies, available under the req.body property.



Example-1: URL / with Get Method.

app.get('/', function (req, res) {
  res.send('Hello, this is Home page.')
})

Example-2: URL /about with Get Method.

app.get('/about', function (req, res) {
  res.send('You have called /about with get method.')
})

Example-3. URL /senddata with POST Method.

app.post('/senddata', function (req, res) {
    //req.body have all the parameter
   console.log(req.body);
  res.send('Hello, Received post data request.')
})

Example-4: Routing with Regex 

app.get('/ab?cd', function (req, res) {
  res.send('ab?cd')
})

This route path will match acd, abcd.


Example-5: Routing with Regex

app.get('/ab+cd', function (req, res) {
  res.send('ab?cd')
})

This route path will match abcd, abbcd, abbbcd, and so on.



Example-6: Routing with dynamic parameter 

app.get('/users/:userId/books/:bookId', function (req, res) {
  console.log(req.params);
   res.send('Received the request for /users/10/book/12222');
});

Request URL: http://localhost:8080/users/10/books/12222


Example-7: Routing with dynamic parameter - Example 2

app.get('/messages/:from-:to', function (req, res) {
  console.log(req.params);
   res.send('Received the request for /messages/10-100');
});

Request URL: http://localhost:8080/messages/10-1000


Question: How to send request with all methods i.e GET/POST/PUT

app.all('/messages/list', function (req, res) {  
   res.send('Work for all type of request');
});

Best Related Posts are Following:

1. How to upload file/images using nodejs?.
2. Express JS - use res.sendFile - use EJS template - Set and Get Session data.
3. How to Create RESTful APIs in Node Js using Express JS and MongoDB.
4. How to use cookies with expressJS in node.js.
5. Express js Interview questions and answers.

NodeJS - call a method after another method is fully executed

Calling a function with callback method

delete_chat_message(messageId,function(result){            
    if(result.success){
        console.log('Chat message is deleted successfully.');
    }else{
        console.log('Unable to delete Chat message.');
    }
});

Function Definition with callback execution

    delete_chat_message=function(messageId, calbackFunc){
    var results = {success: 0, id: messageId}
    
        /* Model to delete the chat message*/
        AjaxChatMessage.remove({id: messageId}, function(err, data) {
            console.log('here');
            if (err) {
                results.success = 0;
            }else{
                results.success = 1;
            }
            //call the callback function
            calbackFunc(results);
        }); 
    }