title: FB.login not triggering in mobile browsers
body: <p>I'm building a mobile web site that directs users through Facebook auth with the following code</p>
  
  <pre><code>(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";
      fjs.parentNode.insertBefore(js, fjs);
  }(document, 'script', 'facebook-jssdk'));
  
  window.fbAsyncInit = function () {
      FB.init({
          appId: '{app_id}', // App ID from the app dashboard
          channelUrl: '{app url}', // Channel file for x-domain comms
          status: true, // Check Facebook Login status
          xfbml: true
      });
  
      FB.login(function (response) {
      //FB.login contents
      }, {
          scope: '{permissions}'
      });
  }
  </code></pre>
  
  <p>This works on desktop browsers but in mobile browsers FB.login doesn't trigger. It seems many people have had this issue. According to <a href="https://stackoverflow.com/questions/11370550/fb-login-not-firing-for-html5-ios-web-app">this</a> Stack Exchange question FB.login cannot be fired inside window.fbAsyncInit and the best way around the issue is to have a button that triggers FB.login once everything is loaded. Can someone authoritative verify that this is my best option before I implement it.</p>