javascript: how to fetch the content of a web page

Question

In JS is it possible to fetch the content of a web page assigning it to a variable? For example, why the following toy code does not work?

var req = new XMLHttpRequest();
req.open('GET', 'http://www.google.com', false);
req.send(null);
if(req.status == 200)
  alert(req.responseText);

Is there a better method/code?

Answer 1

The above does not work, because Ajax requests cannot access files/pages on other domains, due to security concerns. Typically, you can make a script using [Insert Server Side Language here] to download the requested page. Then your javascript can make a request to this page.

There is also 'JSONP', but this is typically used on sites that provide specific JSONP access, which most random URL's do not.

Answer 2

For security reasons, you cannot use AJAX to send a request to a different domain.