How to include javascript on client side of node.js? - javascript

I'm a beginner of node.js and javascript.
I want to include external javascript file in html code. Here is the html code, "index.html":
<script src="simple.js"></script>
And, here is the javascript code, "simple.js":
document.write('Hello');
When I open the "index.html" directly on a web browser(e.g. Google Chrome), It works.
("Hello" message should be displayed on the screen.)
However, when I tried to open the "index.html" via node.js http server, It doesn't work.
Here is the node.js file, "app.js":
var app = require('http').createServer(handler)
, fs = require('fs')
app.listen(8000);
function handler (req, res) {
fs.readFile(__dirname + '/index.html',
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
("index.html", "simple.js" and "app.js" are on same directory.)
I started the http server. (by "bash$node app.js")
After then, I tried to connect "localhost:8000".
But, "Hello" message doesn't appear.
I think the "index.html" failed to include the "simple.js" on the http server.
How should I do?

Alxandr is right. I will try to clarify more his answer.
It happens that you have to write a "router" for your requests. Below it is a simple way to get it working. If you look forward www.nodebeginner.org you will find a way of build a proper router.
var fs = require("fs");
var http = require("http");
var url = require("url");
http.createServer(function (request, response) {
var pathname = url.parse(request.url).pathname;
console.log("Request for " + pathname + " received.");
response.writeHead(200);
if(pathname == "/") {
html = fs.readFileSync("index.html", "utf8");
response.write(html);
} else if (pathname == "/script.js") {
script = fs.readFileSync("script.js", "utf8");
response.write(script);
}
response.end();
}).listen(8888);
console.log("Listening to server on 8888...");

The problem is that nomatter what your browser requests, you return "index.html". So the browser loads your page and get's html. That html includes your script tag, and the browser goes asking node for the script-file. However, your handler is set up to ignore what the request is for, so it just returns the html once more.

Here is a working code.
There should be more cleaner simpler code, but this is very close to minimal.
This code suppose your index.html and other files are under /client dir.
Good luck.
var fs = require('fs');
var url = require("url");
var path = require('path');
var mime = require('mime');
var log = console.log;
var handler = function (req, res)
{
var dir = "/client";
var uri = url.parse(req.url).pathname;
if (uri == "/")
{
uri = "index.html";
}
var filename = path.join(dir, uri);
log(filename);
log(mime.lookup(filename));
fs.readFile(__dirname + filename,
function (err, data)
{
if (err)
{
res.writeHead(500);
return res.end('Error loading index.html');
}
log(data);
log(filename + " has read");
res.setHeader('content-type', mime.lookup(filename));
res.writeHead(200);
res.end(data);
});
}

Your handler is hardcoded to always return the content of /index.html. You need to pay attention to the resource that is being requested and return the right one. (i.e. if the browser asks for simple.js then you need to give it simple.js instead of index.html).

function contentType(ext) {
var ct;
switch (ext) {
case '.html':
ct = 'text/html';
break;
case '.css':
ct = 'text/css';
break;
case '.js':
ct = 'text/javascript';
break;
default:
ct = 'text/plain';
break;
}
return {'Content-Type': ct};
}
var PATH = 'C:/Users/DELL P26E/node_modules'
var http = require("http");
var fs = require('fs');
var url = require("url");
var path = require("path")
var fileName = "D:/index.html";
var server = http.createServer (function (request, response) {
var dir = "D:/";
var uri = url.parse(request.url).pathname;
if (uri == "/") {
uri = "index.html";
}
var filename = path.join(dir, uri);
fs.readFile(filename,
function (err, data) {
if (err) {
response.writeHead(500);
return response.end('Error loading index.html');
}
var ext = path.extname(filename)
response.setHeader('content-type',contentType(ext));
response.writeHead(200);
response.end(data);
});
}).listen(3000);
console.log('Server running on 8124') ;

Related

Can't Load Javascript and CSS files from Node Js

I have read many questions regarding "unable to load js and css files from node js". Looks like a silly path error but since am new to node js, am unable to figure it out.
All of my files are under one folder named "d3". Any ideas where am going wrong?
var http = require('http');
var fs = require('fs');
var url = require('url');
var io = require('socket.io');
var redis = require('redis');
var redis = require("redis")
, subscriber = redis.createClient();
subscriber.subscribe('channel');
var server = http.createServer(function(request, response){
var path = url.parse(request.url).pathname;
switch(path) {
case '/socket.html':
fs.readFile(__dirname + path, function(error, data){
if (error){
console.log("Working " + error);
response.writeHead(404);
response.write("File doesn't exist - 404");
response.end();
}
else{
response.writeHead(200, {"Content-Type": "text/html"});
response.write(data, "utf8");
response.end();
}
});
break;
default:
response.writeHead(404);
response.write("Doesnt Exist");
response.end();
break;
}
});
/* Rest of the code */
server.listen(8000);
When node JS gets a request, you pass the requested path into a switch statement.
If the request is for /socket.html you return an HTML document.
If the request if for anything else (such as my.js), you return a 404 error.
You have to return the JS and CSS when it is requested instead of throwing a 404.

How to display image inside HTML document using node.js [duplicate]

This question already has answers here:
Node JS and Webpack Unexpected token <
(5 answers)
Closed 6 years ago.
I'm displaying some text that i've created inside HTML file using node.js (by method createServer).
Everything was working fine until i added picture inside the document, which doesn't get display on the site.
This is my code
http.createServer(function (req, res) {
res.writeHead(200, { 'Content-Type': 'text/html'});
//read HTML
fs.readFile(__dirname + '//funkcionalnosti.html', function (err, data) {
console.log(data.toString());
res.end(data);
});
This is my code for image inside HTML file
And this is where picture is located
Picture as located same as HTML file, so i dont any ../ are necessary in order for it ti work. I've also tried adding the ful path and subdirectories but the picture won't show.
I've also tried this that i found on stackoverflow, but it's still not working
var image_origial = "diagram.jpg";
fs.readFile(image_origial, function (err, original_data) {
fs.writeFile('diagram.jpg', original_data, function (err) { });
var base64Image = original_data.toString('base64');
var decodedImage = new Buffer(base64Image, 'base64');
fs.writeFile('diagram.jpg', decodedImage, function (err) { });
});
Also tried this
res.write('<img src="data:diagram.jpg/;base64,imagedata">');
Or this
res.write('<img src="data:diagram.jpg/jpg;base64,imagedata">');
But no luck so far, please help me out, im desperate
Any help will be appreciated!!!
How is this a duplicate to "bundle.js:1 Uncaught SyntaxError: Unexpected token <" ?
You need something like this. You haven't handled route for the image that you are trying to access.
var http = require('http');
var fs = require('fs');
var path = require('path');
http.createServer(function (request, response) {
console.log('request starting...');
var filePath = '.' + request.url;
if (filePath == './')
filePath = './index.html';
var extname = path.extname(filePath);
var contentType = 'text/html';
switch (extname) {
case '.js':
contentType = 'text/javascript';
break;
case '.css':
contentType = 'text/css';
break;
case '.json':
contentType = 'application/json';
break;
case '.png':
contentType = 'image/png';
break;
case '.jpg':
contentType = 'image/jpg';
break;
case '.wav':
contentType = 'audio/wav';
break;
}
fs.readFile(filePath, function(error, content) {
if (error) {
if(error.code == 'ENOENT'){
fs.readFile('./404.html', function(error, content) {
response.writeHead(200, { 'Content-Type': contentType });
response.end(content, 'utf-8');
});
}
else {
response.writeHead(500);
response.end('Sorry, check with the site admin for error: '+error.code+' ..\n');
response.end();
}
}
else {
response.writeHead(200, { 'Content-Type': contentType });
response.end(content, 'utf-8');
}
});
}).listen(8125);
console.log('Server running at http://127.0.0.1:8125/');
Original Answer https://stackoverflow.com/a/29046869/2861108

How to upload .txt file to local node.js server and read back the file contents?

Basically, I am creating a small game where I save a list of how many times the user has won to a text file and I then want to upload the contents of that text file to my server and would also like the ability to read the contents from my server. Just wondering what's the best way to do this?
My Server:
var http = require('http');
var fs = require('fs');
var path = require('path');
var PORT = 8080;
var server = http.createServer(function (request, response) {
console.log('connection successful');
var filePath = '.' + request.url;
if(filePath == './'){
filePath = './index.html';
}
var extname = path.extname(filePath);
var contentType = 'text/html';
switch(extname){
case '.js':
contentType = 'text/javascript';
break;
case '.css':
contentType = 'text/css';
break;
}
fs.readFile(filePath, function(error, content) {
if(error){
response.writeHead(500);
response.end();
} else{
response.writeHead(200, {'Content-Type': contentType});
response.end(content, 'utf-8');
}
});
}).listen(8080);
Client code function:
var scoresFile;
function xPlayerWinsF(){
xPlayerWins++;
scoresFile = new File('scoresfile.txt');
scoresFile.wrtiteln("X player wins: "+xPlayerWins);
}
Thanks in advance.

My First Node.js server : Failed to load resource: net::ERR_INCOMPLETE_CHUNKED_ENCODING

The following server is supposed to :
CASE #1 : serve mysitename.html if the request is http://localhost:8080
CASE #2 : serve the relevant file if the request is e.g. http://localhost:8080/mysitename.html
CASE #3 send me an email if the request is http://localhost:8080/contactform?name=..&..&...etc.
If I visit http://localhost:8080/mysitename.htmleverything works fine. mysitename.html is loaded and then all subsequent content (.js, .css, .png etc.) is loaded through it.
PROBLEM : However, if I visit http://localhost:8080, the following happens :
I get a Failed to load resource: net::ERR_INCOMPLETE_CHUNKED_ENCODING error on the browser's (Chrome) console.
`mysitename.html' appears corrupted on the client. Parts of the DOM are missing and when I try to view the source page, it just hangs and never actually loads. Loading only part of the DOM is weird given that all DOM elements of this file are static/hardcoded.
What's confusing is that the rest of the content (.js, .css etc..) is loaded but nothing actually shows because of the corrupted .html. Is it possible that CASE#1 is interrupted by CASE#2 that follows right after it? What exactly am I doing wrong ?
CASE#2 initially had an error which was causing an infinite loop found by Johnny Estilles (see his answer below). This has since been fixed but the issues mentioned above now occur.
server.js
// setting up email handler
var nodemailer = require('nodemailer');
var emailHandlerService = 'Gmail';
var emailHandlerAddress = ******;
var emailHandlerPassword = ******;
var transporter = nodemailer.createTransport({
service: emailHandlerService,
auth: {
user: emailHandlerAddress,
pass: emailHandlerPassword
}
});
// setting up http server
var http = require('http');
var fs = require('fs');
var url = require("url");
var path = require("path");
var rootDir = __dirname + "/public";
var mimeTypes = {
"html": "text/html",
"jpeg": "image/jpeg",
"jpg": "image/jpeg",
"png": "image/png",
/* Even though the js mime type is set as well, scripts are still sent
as "text/plain" according to the Chrome console. Why is that ? */
"js": "application/javascript",
"css": "text/css",
"ico": "image/ico"
};
// initializing server
var httpServer = http.createServer(function (request, response)
{
// CASE #1
// if the user is on http://localhost:8080, load public/mysitename.html
if (request.url === "/")
{
fs.readFile('public/mysitename.html', function (err, html)
{
if (err)
{
response.writeHead(200, {'Content-Type': 'text/plain'});
response.write('404 Not Found\n');
throw (err);
}
else
{
response.writeHeader(200, {"Content-Type": "text/html"});
response.write(html);
}
});
}
// CASE #2
// else if this is a contact form data request
// forward the data to my email (I'll make a more precise Regex for the request)
else if (/contactform/.test(request.url))
{
var parsedURL = url.parse(request.url, true);
var name = parsedURL.query.name;
var email = parsedURL.query.email;
var subject = parsedURL.query.subject;
var enquiry = parsedURL.query.enquiry;
var browser = parsedURL.query.browsername + " " +
parsedURL.query.browserversion;
transporter.sendMail({
from: emailHandlerAddress,
to: emailHandlerAddress,
subject: subject,
text: "|| NAME = " + name + " || EMAIL = " +
email + " || BROWSER = " + browser + " || DEVICE = " +
parsedURL.query.device + " || ENQUIRY = " + enquiry
});
response.end(JSON.stringify(parsedURL.query));
}
// CASE #3
// if none of the above is true then this is a request to serve static files
else
{
var pathname = url.parse(request.url).pathname;
var filename = path.join(rootDir, pathname);
fs.exists(filename, function (exists)
{
if (!exists)
{
fs.readFile('public/404.html', function (err, html)
{
if (err)
{
response.writeHead(200, {'Content-Type': 'text/plain'});
response.write('404 Not Found\n');
throw (err);
}
else
{
response.writeHeader(200, {"Content-Type": "text/html"});
response.write(html);
}
response.end();
});
}
else
{
var requestedFileExtension = path.extname(filename).split(".")[1];
var mimeType = mimeTypes[requestedFileExtension] || 'text/plain';
// as I noted above, this doesn't seem to have any effect
// for my .js files
response.writeHead(200, mimeType);
var fileStream = fs.createReadStream(filename);
fileStream.pipe(response);
}
});
}
}).listen(8080);
FIXING ISSUE #1: Infinite loop
You're missing an equal sign (or two) in your initial if().
Change
if (request.url = "/")
to
if (request.url == "/")
or
if (request.url === "/")
FIXING ISSUE #2: Failed to load resource: net::ERR_INCOMPLETE_CHUNKED_ENCODING
Your're missing a response.end() in CASE #1.
// CASE #1
// if the user is on http://localhost:8080, load public/mysitename.html
if (request.url === "/")
{
fs.readFile('public/mysitename.html', function (err, html)
{
if (err)
{
response.writeHead(200, {'Content-Type': 'text/plain'});
response.write('404 Not Found\n');
throw (err);
}
else
{
response.writeHeader(200, {"Content-Type": "text/html"});
response.write(html);
}
response.end(); // <-- MISSING
});
}

Nodejs output -Domain name not found

Technically this is my first try in nodejs and frankly I am not sure if I am doing it right. I am creating a local server that will stream the output from a distant server. However, when I run my code and I enter a URL in the browser, the program fails with the following message:
events.js:45
throw arguments[1]; // Unhandled 'error' event
^
Error: ENOTFOUND, Domain name not found
at IOWatcher.callback (dns.js:74:15)
The URL I used was: 127.0.0.1:9000/http://www.yahoo.fr. And in the browser I had the following message:
No data received
Unable to load the webpage because the server sent no data.
Here are some suggestions:
Reload this web page later.
Error 324 (net::ERR_EMPTY_RESPONSE): The server closed the connection without sending any data.
Any help is greatly appreciated.
Here is the code:
var base, dest, node_client,
count = 0,
url = require('url'),
util = require('util'),
http = require('http'),
http_client = require('http'),
request = require('request'),
events = require('events'),
httpProxy = require('./lib/node-http-proxy'),
data_emitter = new events.EventEmitter();
httpProxy.createServer(9000, 'localhost').listen(8000);
http.createServer(function (req, res) {
if(!count)
{
base = url.parse(req.url).pathname;
node_client = http_client.createClient(80, base);
count++;
} else {
dest = req.url.substr(1, req.url.length -1);
}
request = node_client.request("GET", dest, {"host": base});
request.addListener("response", function (response) {
var body = "";
response.addListener("data", function (data) {
body +=data;
});
response.addListener("end", function () {
var out = JSON.parse(body);
if(out.length > 0) {
data_emitter.emit("out", out);
}
});
});
// request.close();
var listener = data_emitter.addListener("data", function(out) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(JSON.stringify(out));
res.close();
});
}).listen(9000);
Wild guess : your browser automatically requests 127.0.0.1:9000/favicon.ico and your program then tries to resolve favicon.ico which obviously fails and makes your program crash before it can send any data for the real request.
Why such tangled code?
This is a scenario where it makes sense to avoid nested callbacks, and use named functions. If you refactor the code, then people are more likely to be help you.
Can you do console.log(out) in your listener callback? Let us know if Node.js has any response data to return.
Well, for any newbie like me in this area, here is how I solved it. It's not clean and can be implemented in better way. Feel free to change, give suggestions.
Code:
var url = require('url'),
http = require('http'),
request = require('request'),
httpProxy = require('./lib/node-http-proxy'),
des = '',
util = require('util'),
colors = require('colors'),
is_host = true;
httpProxy.createServer(9000, 'localhost').listen(8000);
var server = http.createServer(function (req, res) {
var pathname = '';
if(is_host) {
dest = req.url.substr(0, req.url.length -1);
pathname = dest;
is_host = false;
} else {
pathname = req.url.substr(0, req.url.length);
if(pathname.charAt(0) == "/") {
console.log('new request');
console.log(pathname);
pathname = dest + pathname;
}
}
console.log(pathname);
request.get({uri: pathname}, function (err, response, html) {
res.end(html);
});
console.log('fetched from ' + pathname);
});
server.listen(9000);

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