gistfile1.js

/**
 * Usage:
 * 
 *  scout()
 *   .when(typeof JSON === 'undefined')
 *   .load('/assets/json2.js')
 *
 *   .when(typeof G_vmlCanvasManager !== 'undefined')
 *   .load('/assets/fabric/cufon.js')
 *
 *   .afterAll(function() {
 *     initEditor();
 *   });
 */
function scout() {

  var testsToLoad = 0, tests = [ ];
  var lastExpression;
  var afterAllCallback;

  function checkCompletion() {
    if (testsToLoad === 0) {
      afterAllCallback();
    }
  }

  var self = {
    when: function(val) {
      lastExpression = val;
      return self;
    },
    load: function(str) {
      if (lastExpression) {
        testsToLoad++;
        tests.push(str);
      }
      return self;
    },
    afterAll: function(callback) {

      afterAllCallback = callback;
      checkCompletion();

      for (var i = 0; i < tests.length; i++) {
        jQuery.getScript(tests[i], function() {
          testsToLoad--;
          checkCompletion();
        });
      }

      return self;
    }
  }

  return self;
}