Develop Reference

prerender.io with native Node.js

Im trying to implement prerender.io for my Angular 1.6.0 app running on a native Node.js server
The documentation for setting up the middleware makes use of the connect middleware and specifically cites Express.js
app.use(require('prerender-node').set('prerenderToken', 'TOKEN'));
I am not using Express and was not using the Connect middleware to run my server.
My server.js is as follows:
var app = http.createServer(function(req, res){
var filePath = './debug/index.html';
var uri = req.url;
// Load index.html only when uri is not referencing a sub-directory of ./www (and is thus a URL)
for(i in dir){
if(uri.includes('/'+dir[i])) {
filePath = './debug'+uri;
break;
}
}
fs.exists(filePath, function(exists) {
if(exists){
fs.readFile(filePath, function(err, html) {
if(err){ res.writeHead(500); res.end(); }
else {
var ext = path.extname(filePath);
var contentType = 'text/html';
switch(ext) {
case '.js':
contentType = 'text/javascript';
break;
case '.css':
contentType = 'text/css';
break;
case '.jpg':
contentType = 'image/jpeg';
break;
case '.png':
contentType = 'image/png';
break;
case '.svg':
contentType = 'image/svg+xml';
break;
case '.pdf':
contentType = 'application/pdf';
break;
default: contentType = 'text/html';
}
res.writeHead(200, { 'Content-Type': contentType });
res.end(html, 'utf-8');
}
});
} else {
res.writeHead(404);
res.end();
}
});
}).listen(port, function(){
console.log('server is running on port '+port);
});
1) How can I implement prerender.io with this configuration?
2) I did actually install Connect and trying to implement the middleware as follows:
var conn = connect();
conn.use(require('prerender-node').set('prerenderServiceUrl','http://localhost:3000/').set('prerenderToken', 'lqnF62jXABouJiFA2SuA'));
Which I just appended after the server code above.
I am not getting any errors but I do not see that anything at localhost:3000 after running node server. Although, my app runs fine on localhost:8080
How can I get prerender.io set up on this server?

You might could do something like the following, but I'd suggest breaking each function out into its own function to prevent all of the callbacks. Just wanted to leave the code alone so you could see where it was changed.
var prerender = require('prerender-node').set('prerenderToken', 'TOKEN');
var app = http.createServer(function(req, res){
prerender(req, res, function() {
var filePath = './debug/index.html';
var uri = req.url;
// Load index.html only when uri is not referencing a sub-directory of ./www (and is thus a URL)
for(i in dir){
if(uri.includes('/'+dir[i])) {
filePath = './debug'+uri;
break;
}
}
fs.exists(filePath, function(exists) {
if(exists){
fs.readFile(filePath, function(err, html) {
if(err){ res.writeHead(500); res.end(); }
else {
var ext = path.extname(filePath);
var contentType = 'text/html';
switch(ext) {
case '.js':
contentType = 'text/javascript';
break;
case '.css':
contentType = 'text/css';
break;
case '.jpg':
contentType = 'image/jpeg';
break;
case '.png':
contentType = 'image/png';
break;
case '.svg':
contentType = 'image/svg+xml';
break;
case '.pdf':
contentType = 'application/pdf';
break;
default: contentType = 'text/html';
}
res.writeHead(200, { 'Content-Type': contentType });
res.end(html, 'utf-8');
}
});
} else {
res.writeHead(404);
res.end();
}
});
});
}).listen(port, function(){
console.log('server is running on port '+port);
});
As for your second question, you might have it installed correctly. Do you see a request on your prerender server console if you go to:
http://localhost:8080/?_escaped_fragment_=

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.

Node.js - Styles doesn't apply to page & Google Chrome says: Uncaught SyntaxError: Unexpected token <

I began studying node.js and stuck at the beginning. I was trying to solve this problem several times but no succeed. I was googling, stackoverflowing and found problems like mine. But not exactly or solutions doesn't work for me. Please, help me!
I have simple index.html file with following content:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>SimpleApp</title>
<link rel="stylesheet" type="text/css" href="styles/default.css" />
</head>
<body>
Hello, Node!
<script src="js/application.js"></script>
</body>
</html>
And here is simple server in server.js file:
var http = require('http');
var mime = require('mime');
var fs = require('fs');
var server = http.createServer(function(request, response) {
fs.readFile('./index.html', function(error, data) {
if(error) {
response.writeHead(404, {'Content-Type' : 'text/html'});
response.end('<h1>File <index.html> not found.</h1>');
} else {
var contentType = undefined;
if(request.url === '/') {
contentType = 'text/html';
} else {
contentType = mime.lookup(request.url);
}
response.writeHead(200, {'Content-Type' : contentType});
response.end(data);
}
});
});
server.listen(8000, function() {
console.log('Server started.');
})
After I start server - styles doesn't apply to page & Google Chrome says: Uncaught SyntaxError: Unexpected token <.
I know problem inside fs.readFile callback,inside else, but what?

Here is a solution (need to be refactored):
server.js
var http = require('http');
var mime = require('mime');
var fs = require('fs');
var server = http.createServer(function(request, response) {
var filePath = undefined;
var contentType = undefined;
switch(request.url) {
case '/':
filePath = './index.html';
contentType = 'text/html';
break;
case '/styles/default.css':
filePath = './styles/default.css';
contentType = mime.lookup(request.url);
break;
case '/js/application.js':
filePath = './js/application.js';
contentType = mime.lookup(request.url);
break;
default:
filePath = request.url;
contentType = mime.lookup(request.url);
}
fs.readFile(filePath, function(error, data) {
response.writeHead(200, {'Content-Type' : contentType});
response.end(data);
});
});
server.listen(8000, function() {
console.log('Server started.');
});

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
});
}

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

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') ;