Foolproof way to detect if this page is INSIDE a cross-domain iframe

Question

An answer to \"Foolproof way to detect if iframe is cross domain\" describes a method to test if an iframe on a page points to a same-domain or cross-domain page, working ar

Answer 1

Real cross-browser solution for posterity:

function isCrossOriginFrame() {
  try {
    return (!window.top.location.hostname);
  } catch (e) {
    return true;
  }
}

console.log(isCrossOriginFrame());

Tested on a decent swath of desktop and mobile browsers.

https://jsfiddle.net/arzd4btc/3/

Answer 2

For nested iframes : a recursive way to know if iframe (where this code is executed) is cross domain or not :

function crosDomIfrm(win, data) {
        data = (typeof data === 'undefined')?{ref:win.document.location,isCD:false}:data;
        try { 
            if( win.document.referrer != '' ){
                data.isCD = parseURL(data.ref) != parseURL(win.document.referrer);
            }
        } catch(e){}
        if ( (win.self !== win.parent) && !data.isCD ) { //I'm in iframe
            data = crosDomIfrm( win.parent, data );
        }
        return {ref:data.ref,isCD:data.isCD};
    },

function parseURL(url) {
                var a=document.createElement('a');
                a.href=url;
                return a.hostname;
            }