Attempting to run the following JavaScript code (an AJAX call using XMLHttpRequest) throws a ReferenceError under Node, but works in a web browser.
Reproducing the problem
The code sample below uses the browser's XMLHttpRequest object to make an asynchronous HTTP GET request for the file book.json.
This is a standard AJAX call.
To run under Node (and see the error), type:
node test.js
Test.js:
var xhr = new XMLHttpRequest();
xhr.open("GET", "/demo/book.json");
xhr.onreadystatechange = function () {
console.log("readyState = " + this.readyState + ", status = " + this.status);
if (this.readyState == 4 && this.status == 200) {
var result = this.responseText;
console.log(result);
}
};
xhr.send();Explanation
The XMLHttpRequest type is natively supported in web browsers only.
It is not part of Node, but it can be installed as a package using npm.
The fix
1) Install xmlhttprequest using npm.
npm install xmlhttprequest --save
2) Add require("xmlhttprequest").
The code will now work under node.
Only the first line is new. The rest is the same.
Test.js (updated):
var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
var xhr = new XMLHttpRequest();
xhr.open("GET", "/demo/book.json");
xhr.onreadystatechange = function () {
console.log("readyState = " + this.readyState + ", status = " + this.status);
if (this.readyState == 4 && this.status == 200) {
var result = this.responseText;
console.log(result);
}
};
xhr.send();