I wrote a very simple program to demonstrate request handling in Node (actually following a tutorial), but the server seems to take forever to respond to the GET / request. Here's the code I'm using:
const http = require('http');
const url = require('url');
let routes = {
'GET': {
'/': (req, res) => {
res.writeHead(200, {'Content-type': 'text/html'});
res.end('GET /');
}
},
'POST': {
},
'NA': (req, res) => {
res.writeHead(404);
res.end('Content not found');
}
}
function router(req, res) {
let baseURI = url.parse(req.url, true);
// the function that gets resolved and used to handle the request
let resolveRoute = routes[req.method][baseURI.pathname];
}
http
.createServer(router).listen(3001, () => {
console.log('Listening on port 3001');
});
Something I'm doing wrong?
Found it myself.
I was resolving the handler function but not calling it. Adding resolveRoute(req, res); to the end of the router() function makes it work. :)
Related
I'm new programmer to node.js. I trying to create vanilla server in node.js. In my client, I used ES6 modules. when I start my server and search for http://localhost:3000/ in my browser, HTML and CSS loaded but for javascript have this error:
I have four javascript modules for client side and in HTML I use this code for load javascript moduls:
<script type="module" src="js/controller.js" async></script>
My server code :
const http = require('http');
const fs = require('fs');
const path = require('path');
const PORT = 3000;
const server = http.createServer();
server.on('request', (req, res) => {
let routes = {
'GET': {
'/': indexHtml,
}
}
console.log(req.url)
let handler = routes[req.method][req.url];
handler = handler || readFile;
handler(req, res);
})
server.listen(PORT, () => {
console.log(`Listening on port ${PORT}...`)
});
function indexHtml(req, res) {
readFile({ url: '/index.html' }, res);
}
function readFile(req, res) {
var filePath = path.join(__dirname, '../client/', req.url);
// console.log(filePath)
fs.readFile(filePath, (error, data) => {
if (error) {
res.writeHead(404);
res.write('Not found error 404');
res.end()
} else {
res.writeHead(200);
res.write(data);
res.end();
}
})
}
How can I solve this error and serve javascript modules, Thanks a lot for your help.
With comment #derpirscher, I change my reader function with this code :
function readFile(req, res) {
var filePath = path.join(__dirname, '../client/', req.url);
fs.readFile(filePath, (error, data) => {
if (error) {
res.setHeader('Content-Type', 'text/html');
res.writeHead(404);
res.write('Not found error 404');
res.end()
} else {
const url = req.url === '/' ? '/index.html' : req.url;
if (req.url.includes('js')) res.setHeader('Content-Type', 'application/javascript');
if (req.url.includes('css')) res.setHeader('Content-Type', 'text/css');
if (req.url.includes('html')) res.setHeader('Content-Type', 'text/html');
res.writeHead(200);
res.write(data);
res.end();
}
})
}
Is it possible in Node.js to return HTML (e.g. <div>Test</div>) as response to client?
I saw that option in Express on sendFile() method().
Is there something similar in Node?
I found this solution:
var myHtmlData;
fs.readFile('./index.html', (err, data) => {
if(err){
throw err;
} else {
myHtmlData = data
}
})
// and after use it
response.write(myHtmlData)
But I was wondering is it possible to do it with some method similar to sendFile() to write html directly like this <div>Test</div> without reading it from another file.
Sure. It's pretty simple. The following code returns the response as HTML to the client.
var http = require('http');
http.createServer(function(req, res){
if(req.url === "/"){
res.writeHead(200, { 'Content-Type':'text/html'});
res.end("<div><p>Test<p></div>");
}
}).listen(3000);
And in case you want to serve an HTML or JSON file as a response, you can execute the following code.
var http = require('http');
var fs = require('fs');
http.createServer(function(req, res){
if(req.url === '/I_want_json'){
res.writeHead(200, { 'Content-Type':'application/json'});
var obj = {
firstName: "Jane",
lastName: "Doe",
};
res.end(JSON.stringify(obj));
}
else if (req.url === '/I_want_html'){
res.writeHead(200, { 'Content-Type':'text/html'});
html = fs.readFileSync('./index.html');
res.end(html);
}
else{
res.writeHead(404);
res.end();
}
}).listen(3000, '127.0.0.1');
Do not forget to set the Content-Type as mentioned since it is a mandatory part for client to distinguish the type of response.
First, you need to mention the content type as HTML. Then read the HTML file using fs module and send its data as a response. Don't forget to end the response using end() method.
const http = require('http');
const fs = require('fs');
const server = http.createServer((req, res) => {
res.setHeader("Content-Type", "text/html");
fs.readFile('./views/index.html', (err, data) => {
if(err) {
console.log(err);
res.end();
} else {
res.write(data);
res.end();
}
})
});
below node.js code is using express to route to different urls, how can I do the same with http instead of express?
var express = require('express');
var app = express();
app.use(express.static('public'));
app.get('/', function (req, res) {
res.send('Welcome Home');
});
app.get('/tcs', function (req, res) {
res.send('HI RCSer');
});
// Handle 404 - Keep this as a last route
app.use(function(req, res, next) {
res.status(404);
res.send('404: File Not Found');
});
app.listen(8080, function () {
console.log('Example app listening on port 8080!');
});
Here's a quick example. Obviously, there are many ways of doing this, and this is probably not the most scalable and efficient way, but it will hopefully give you an idea.
const http = require('http');
const fs = require('fs');
const server = http.createServer((req, res) => {
req.on('error', err => {
console.error(err);
// Handle error...
res.statusCode = 400;
res.end('400: Bad Request');
return;
});
res.on('error', err => {
console.error(err);
// Handle error...
});
fs.readFile('./public' + req.url, (err, data) => {
if (err) {
if (req.url === '/' && req.method === 'GET') {
res.end('Welcome Home');
} else if (req.url === '/tcs' && req.method === 'GET') {
res.end('HI RCSer');
} else {
res.statusCode = 404;
res.end('404: File Not Found');
}
} else {
// NOTE: The file name could be parsed to determine the
// appropriate data type to return. This is just a quick
// example.
res.setHeader('Content-Type', 'application/octet-stream');
res.end(data);
}
});
});
server.listen(8080, () => {
console.log('Example app listening on port 8080!');
});
Try the code below . It is a pretty basic example
var http = require('http');
//create a server object:
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'}); // http header
var url = req.url;
if(url ==='/about'){
res.write('<h1>about us page<h1>'); //write a response
res.end(); //end the response
}else if(url ==='/contact'){
res.write('<h1>contact us page<h1>'); //write a response
res.end(); //end the response
}else{
res.write('<h1>Hello World!<h1>'); //write a response
res.end(); //end the response
}
}).listen(3000, function(){
console.log("server start at port 3000"); //the server object listens on port 3000
});
express can also be used by http directly.
From: https://expressjs.com/en/4x/api.html#app.listen
The app returned by express() is in fact a JavaScript Function, designed to be passed to Node’s HTTP servers as a callback to handle requests.
var http = require('http')
var express = require('express')
var app = express()
http.createServer(app).listen(80)
With this, you can still make use of express for routing, while keeping native http support.
What I want to do is to make a request using the "request" module when server receives a request, and return the content of that "request" back to the client. Is it possible?
const http = require("http");
const request = require("request");
const URL = "???";
const server = http.createServer();
server.on('request', (req, res) => {
// called once for every HTTP request
out_res = res;
make_request((err, res, body) => {
out_res.writeHead(200, {res});
out_res.write(body);
out_res.end();
});
});
function make_request(callback) {
request(URL, (err, res, body) => {
callback(err, res, body);
});
}
module.exports = () => {
server.listen(8080);
console.log('server start');
};
I got an error: ERR_STREAM_WRITE_AFTER_END, I've been a long time without node.js, but my friend asked me about some code and I just rewrite as above.
Ofcourse you can do that
server.on('request', (req, res) => {
request({uri: URL}).pipe(res);
});
Just pipe the response of API call to your router response object.
Here is how I would advise you to write your server code
var server = http.createServer(function(req,res){
if(req.url === '/' || req.url === '/index'){
request({uri: URL}).pipe(res);
}
.... //other conditions
});
server.listen(3000,'127.0.0.1')
Moreover, you can/should consider using express, it's really cool and easy to use to define routes etc
I have the following simple code for a nodejs server....
var http = require('http');
var port = 1337;
var dispatcher = require('httpdispatcher');
dispatcher.setStaticDirname(__dirname);
dispatcher.setStatic('');
dispatcher.onGet("/page1", function (req, res) {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Page One');
});
var server = http.createServer().listen(port);
server.on('request', function (req, res) {
console.log('GOT');
dispatcher.dispatch(req, res);
});
console.log('Listening on port %s', port);
when I goto http://localhost:1337/index.html it is showing up correctly but when I do http://localhost:1337/page1 nothing happens...how can I get it to function properly...
You need to define your custom dispatcher events, in this case "/page1", before setting the static dispatcher. Otherwise static hogs every possible path remaining to check against the file system.
dispatcher.onGet("/page1", function (req, res) {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Page One');
});
dispatcher.setStaticDirname(__dirname);
dispatcher.setStatic('');
Your revised code will look like this:
var http = require('http');
var port = 1337;
var dispatcher = require('httpdispatcher');
dispatcher.onGet("/page1", function (req, res) {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Page One');
});
dispatcher.setStaticDirname(__dirname);
dispatcher.setStatic('');
var server = http.createServer().listen(port);
server.on('request', function (req, res) {
console.log('GOT');
dispatcher.dispatch(req, res);
});
console.log('Listening on port %s', port);
Tested and works