Use Recaptcha without unsafeWindow?

Question

I already read these methods as alternative for unsafeWindow. But I still can't get it works to use the Recaptcha object without unsafeWindow. My code using unsafeWindow is (this code works fine):

var myscript= document.createElement('script');
myscript.setAttribute('src','http://www.google.com/recaptcha/api/js/recaptcha_ajax.js');
document.body.appendChild(myscript);
Recaptcha = unsafeWindow.Recaptcha; 
Recaptcha.create(theKey,"recaptcha_widget_div",{theme:"red"});

I tried this with no luck:

//after script inject
Recaptcha = location.assign("javascript:Recaptcha();void(0)");
Recaptcha.create(theKey,"recaptcha_widget_div",{theme:"red"});

What did I do wrong with the location hack?

Note that I want the code to be usable in a Chrome content script, too.

Answer 1

location.assign() loads a new page; "poofing" away the script and any variables like Recaptcha.

In this case, go ahead and use unsafeWindow. It's not really that big a deal unless you know a webmaster is targeting Greasemonkey scripts.

It's even less dangerous in this case, because you are adding the recaptcha code. The target page isn't.

---

Update:
The OP indicated that this is to work in Chrome content scripts too. In that case, inject both parts like so:

function addJS_Node (text, s_URL) {
    var D                                   = document;
    var scriptNode                          = D.createElement ('script');
    if (text)       scriptNode.textContent  = text;
    if (s_URL)      scriptNode.src          = s_URL;

    var targ = D.getElementsByTagName ('head')[0] || D.body || D.documentElement;
    targ.appendChild (scriptNode);
}

addJS_Node (null, 'http://www.google.com/recaptcha/api/js/recaptcha_ajax.js');

//-- Might need a delay here, but probably not.
addJS_Node ('Recaptcha.create(theKey,"recaptcha_widget_div",{theme:"red"});');