Question

What am I doing wrong? – I’m trying to grab the user’s locale from a facebook iframe tab to display relevant content based on location.

    <script type="text/javascript">
        (function (d, s, id) {
            var js, fjs = d.getElementsByTagName(s)[0];
            if (d.getElementById(id)) return;
            js = d.createElement(s); js.id = id;
            js.src = "//connect.facebook.net/en_US/all.js#xfbml=1&appId=" + 'MY APP ID';
            fjs.parentNode.insertBefore(js, fjs);
        } (document, 'script', 'facebook-jssdk'));

        window.fbAsyncInit = function () {
            if (location.protocol == 'https:') {
                FB._https = true;
            };
            FB.init({
                appId: 'MY APP ID',
                status : false,
                cookie : false,
                xfbml  : true,
            width: 810
            });
            FB.Canvas.scrollTo(0,0);
            FB.Canvas.setAutoGrow();
        }
</script>
<script>
FB.login(function(response) {
    if (response.authResponse) {
        if ($.data.get('user').get('locale') = "en_GB") {
            $("a").attr("href", "URL");
        }
    }
});
</script>

Answer 1

I don’t know much about jQuery, but here’s something that should work:

FB.login(function(response) {
    if (response.authResponse && response.authResponse.user.locale == "en_GB") {
        $("a").attr("href", "URL");
    }
});

---

Edit

Oh yeah.
The loading of the fb sdk is asynced, and so you need to use the FB namespace only after the fbAsyncInit method was called.
Try this:

window.fbAsyncInit = function () {
    if (location.protocol == 'https:') {
        FB._https = true;
    };
    FB.init({
        appId: 'MY APP ID',
        status : false,
        cookie : false,
        xfbml  : true,
        width: 810
    });
    FB.Canvas.scrollTo(0,0);
    FB.Canvas.setAutoGrow();

    FB.login(function(response) {
        if (response.authResponse && response.authResponse.user.locale == "en_GB") {
            $("a").attr("href", "URL");
        }
    });
}

(function (d, s, id) {
    var js, fjs = d.getElementsByTagName(s)[0];
    if (d.getElementById(id)) return;
    js = d.createElement(s); js.id = id;
    js.src = "//connect.facebook.net/en_US/all.js#xfbml=1&appId=" + 'MY APP ID';
    fjs.parentNode.insertBefore(js, fjs);
} (document, 'script', 'facebook-jssdk'));

Just be aware that FB.login tries to popup a new window and since in this code the method is not being called due to a user action, the browser will probably block the popup.