I have some code that in short, is opening an iframe (let's call it iframe1) to view a pdf file, and that pdf is being shown in an iframe itself (let's call it iframe2), I would like to be able to get the source of the iframe2 that is within an iframe1 that would be opened so that the iframe1 itself is just the src of the pdf iframe2 and not 2 different iframes. The Url's are very different.

what is the best way to do this?

I have an open_iframe function that looks something like

function open_iframe(url) {
    return '<iframe id="iframe" src="' + url + '" width=100% height=100% frameborder="0" allowfullscreen></iframe>';
}

and I am writing another function that is

function find_file_url(url) {
    let iframe = this.open_iframe(url);
    return iframe.contentWindow.document.getElementsByTagName('iframe')[0].src;
}

I also have Jquery available to use as well.

Is this something that's possible?

Is there a better approach?

Thanks in advance!