Safari not catching exception when trying to access parent window object with Javascript try/catch

Question

So the code below can be seen working via the fiddle link. Safari is refusing to catch the exception- I am assuming this may be because it is not a 'Javascript' error? Either way, if you run the code in any other browser, you will see the page URL in the console.

The purpose of the function is find the page URL when executed multiple iframes deep on the page. If anyone can confirm why Safari won't catch the error and/or maybe offer a solution, that would be great...Thanks!

function logURL() {
    var oFrame = window, 
        exception = false;

    try {
        while (oFrame.parent.document !== oFrame.document) {
            oFrame = oFrame.parent;
        }
    } catch (e) {
        exception = true;
    }

     if(exception) {
         console.log('excepted', oFrame.document.referrer);
     } else {
         console.log('no exception', oFrame.location.href);
     }
}

http://jsfiddle.net/HPu9n/82/

Answer 1

While an error is logged to the Safari console, Safari apparently does not thrown a JavaScript exception when accessing a window property across frame origins. Instead, Safari simply returns undefined for any property which is not accessible cross-origin.

With this knowledge, we can simply check if oFrame.parent.document is set, and if it's not, break off the loop an do what would happen if the browser threw an exception.

Example (JSFiddle):

function logURL() {
    var oFrame = window, 
        exception = false;

    try {
        while (oFrame.parent.document !== oFrame.document) {
            //Check if document property is accessible.
            if (oFrame.parent.document) {
                oFrame = oFrame.parent;
            }
            else {
                //If document was not set, break the loop and set exception flag.
                exception = true;
                break;
            }
        }
    } catch (e) {
        exception = true;
    }

    if(exception) {
        console.log('excepted', oFrame.document.referrer);
    } else {
        console.log('no exception', oFrame.location.href);
    }
}
logURL();

Logs:

excepted http://jsfiddle.net/ggh0a0f4/