使用 JavaScript 获取特定页面的源代码

Question

The code below displays the source code of the current page:

Website as example: http://jsfiddle.net/635YY/1/

var url="../635YY",xmlhttp;//Remember, same domain
if("XMLHttpRequest" in window)xmlhttp=new XMLHttpRequest();
if("ActiveXObject" in window)xmlhttp=new ActiveXObject("Msxml2.XMLHTTP");
xmlhttp.open('GET',url,true);
xmlhttp.onreadystatechange=function()
{
    if(xmlhttp.readyState==4)alert(xmlhttp.responseText);
};
xmlhttp.send(null);

How to display the source code of another page (other than the current page)?

Answer 1

url="/about";

var xhr = new XMLHttpRequest();
xhr.onload = function() {

  alert( this.responseXML.documentElement.innerHTML );

}
xhr.open( 'GET', url );
xhr.responseType = 'document';
xhr.send();

Unfortunately you will not be able to do this with pages on another website unless the CORS policy on the website allows it, or you will get an error like

Access to XMLHttpRequest at 'https://test.com/' from origin 'http://jsfiddle.net' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.