simple ajax request to localhost nodejs server - ajax

Question

I wrote very simple server :
/* Creating server */
var server = http.createServer(function (request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.end("Hello World\n");
});
/*Start listening*/
server.listen(8000);
I run it using nodejs.
Now i want to write simple client that use ajax call to send request to server and print response (Hello World)
Here javascript of clinet:
$.ajax({
type: "GET",
url: "http://127.0.0.1:8000/" ,
success: function (data) {
console.log(data.toString);
}
});
When I open client html file i get following error in console:
XMLHttpRequest cannot load http://127.0.0.1:8000/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.
I tried adding to ajax call following:
$.ajax({
type: "GET",
url: "http://127.0.0.1:8000/" ,
dataType: 'jsonp',
crossDomain: true,
success: function (data) {
console.log(data.toString);
}
});
But then i get
Resource interpreted as Script but transferred with MIME type text/plain: "http://127.0.0.1:8000/?callback=jQuery211046317202714271843_1410340033163&_=1410340033164".
Anyone can explain what i did wrong and perhaps how to fix it?
Many thanks!

Answer 1

To overcome the CORS, in your node.js file write the below, based on what you need:
// Website you wish to allow to connect
res.setHeader('Access-Control-Allow-Origin', '*');
// Request methods you wish to allow
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
// Request headers you wish to allow
res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
res.setHeader('Access-Control-Allow-Credentials', true);

Answer 2

The first error is caused by CORS (Cross Origin Resource Sharing) policy. It's rule by all browsers that you cannot make a request to a remote server in AJAX other than to the current server the script/page was loaded from unless that remote server allows it via Access-Control-Allow-Origin header.
I suggest serving the page from the same Node.js server. Then it will work. Example, when the request comes to root / page, then serve the index.html file, otherwise, server whatever other content you want.
var http = require('http'),
fs = require('fs');
/* Creating server */
var server = http.createServer(function (request, response) {
if (request.url == '/' || request.url == '/index.html') {
var fileStream = fs.createReadStream('./index.html');
fileStream.pipe(response);
} else {
response.writeHead(200, {"Content-Type": "text/plain"});
response.end("Hello World\n");
}
});
/*Start listening*/
server.listen(8000);