how to ensure sequential order of this javascript?

Question

To begin my page i do a check with facebook to get the login status of the user. I then create a namespace within the window object for use in other javascript files. Before I load any other javascript i need this namespace to be created, or else it will be undefined when i try to access it. Sometimes it completes first, and sometimes it does not. How can i make sure that it happens correctly every time?

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.
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        FB.getLoginStatus(function(response) {
          // store data on the user inside of a namespace 
          // inside of the window object so it can be accessed
          // from anywhere. Use this like '$_SESSION'
          console.log('doing it');
          window.easyUserData = {
            fbRespose: response,
            site: <?php echo '"'.$site.'"'; ?>
          };
        })
      };

      (function(d) {
        var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
        if (d.getElementById(id)) {return;}
        js = d.createElement('script'); js.id = id; js.async = true;
        js.src = "//connect.facebook.net/en_US/all.js";
        ref.parentNode.insertBefore(js, ref);
      }(document))
    </script>
    <!-- Load the script "js/main.js" as our entry point for require -->
    <script data-main="js/main" src="lib/Require/require.js"></script>

specifically, i need the:

<script data-main="js/main" src="lib/Require/require.js"></script>

to not happen until the facebook function is complete

T.J. Crowder · Accepted Answer · 2013-01-01 10:33:30Z

1

Move the code relying on the namespace into the Facebook callback. If it's the <script data-main="js/main" src="lib/Require/require.js"></script>, create the script element dynamically:

  // ...

  FB.getLoginStatus(function(response) {
    // store data on the user inside of a namespace 
    // inside of the window object so it can be accessed
    // from anywhere. Use this like '$_SESSION'
    console.log('doing it');
    window.easyUserData = {
      fbRespose: response,
      site: <?php echo '"'.$site.'"'; ?>
    };

    // Create the script element when ready
    var script = document.createElement('script');
    script.setAttribute("data-main", "js/main");
    script.src = "lib/Require/require.js";
    document.getElementsByTagName('script')[0].parentNode.appendChild(script);
    // Or instead of `document.getElementsByTagName('script')[0].parentNode`
    // you can use `document.documentElement` or `document.getElementsByTagName('head')[0]
    // or a few others
  })
};

edited Jan 1, 2013 at 10:33

answered Jan 1, 2013 at 10:28

T.J. Crowder

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2 Comments

Troy Cosentino Over a year ago

sorry about that, i need the "<script data-main="js/main" src="lib/Require/require.js"></script>" to happen after the fb callback

T.J. Crowder Over a year ago

@TroyCosentino: That was my second guess, just added. :-)

powerbuoy · Accepted Answer · 2013-01-01 10:40:02Z

0

You could move it all to one place as TJ suggests. Or you could check to see if your variable is created before attempting to run your own code:

// First this:
FB.getLoginStatus(function(response) {
    window.easyUserData = {
        fbRespose: response,
        site: <?php echo '"'.$site.'"'; ?>
    };
});

// Later in the code:
(function () {
    var isFBLoaded = function () {
        // If FB has loaded - run our code
        if (window.easyUserData) {
            myOtherFBStuff();
        }
        // If not - check again in 500 ms
        else {
            setTimeout(isFBLoaded, 500);
        }
    };

    var myOtherFBStuff = function () {
        // do stuff here
    };

    isFBLoaded();
})();

answered Jan 1, 2013 at 10:40

powerbuoy

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