Question

I found the snippet below for creating an iframe:

I’d like to only load the textual content at http://www.host.com and make the iframe invisible using display:none

Background:

I need an effective way to parse out the favicon location. Not all site have a default location. For example <link rel="SHORTCUT ICON" href="../images/logo_small.ico" />.

Hence all I need are the textual contents. PHP has a function that does this ( file_get_contents) but I want to do it on the client side.

Here is the mdn documentation on iframe

For server-side PHP use file_get_contents.

function makeFrame() {
   ifrm = document.createElement("IFRAME");
   ifrm.setAttribute("src", "http://www.host.com");
   ifrm.style.width = 640+"px";
   ifrm.style.height = 480+"px";
   document.body.appendChild(ifrm);
} 

Example of Delicious Bookmarklet:

javascript:(function()
{
    f='http://www.delicious.com/save?url='+encodeURIComponent(window.location.href)+
    '&title='+encodeURIComponent(document.title)+'&notes='+
    encodeURIComponent(''+
    (window.getSelection?window.getSelection():document.getSelection?
    document.getSelection():document.selection.createRange().text))+'&v=6&';
    a=function()
    {
        if(!window.open(f+'noui=1&jump=doclose','deliciousuiv6','location=1,links=0,scrollbars=0,to
        olbar=0,width=710,height=660'))
        {
            location.href=f+'jump=yes'
        }
    };
    if(/Firefox/.test(navigator.userAgent))
    {
        setTimeout(a,0);
    }
    else
    {
        a();
    }
})()

Answer 1

You will only have access to the link element in the iframe when both yours and the framed page are in the same domain. To cite the docs you found:

Scripts trying to access a frame’s content are subject to the same-origin policy, and cannot access most of the properties in the other window object if it was loaded from a different domain.

Therefore, it will be needed to use a PHP solution. Load a given domain, use a tagsoup parser and query the dom for link[rel="SHORTCUT ICON"].

You can create a JSON API with that solution, which can be used over Ajax from the clientside js code of your application.