Progressive Degradation

/*globals SWFObject deconcept dcsMultiTrack escape */
 
/* Assistive Technology Checker
 * Version: 1.0
 * 2009/04/29
 * Author: George Walters II (walterg2_NOSPAM_@gmail.com)
 * Remove _NOSPAM_ to send me any comments/suggestions on improvements
 */
 
/* To launch:  as soon as possible, simply add in assistiveTech.init(debug); where debug is either true or false. 
 * This will allow for the flash to run in as little time as possible and mitigate as much of the delay in this
 * code running as possible.
 * Requires: SWFObject
 */
 
var assistiveTech = {
  assistiveTechLocale: "./flash/assistiveTech.swf",
  replacementDiv: "assistiveTech",
  requireVersion: "9",
  debug: false,
  debugFlag: "",
  techAssist: false,
  cookieName: "assistiveTech",
  init: function(debugFlag){
    assistiveTech.debug = (debugFlag) ? assistiveTech.debugCheck(debugFlag) : assistiveTech.debug;
	var cookieCheck = assistiveTech.cookieExists();
    if (!cookieCheck) {
      var so = new SWFObject(assistiveTech.assistiveTechLocale, "assistiveTechSwf", 1, 1, assistiveTech.requireVersion);
      so.addParam("quality", "low");
      so.addParam("allowScriptAccess", "all");
 
      // Pass the success handler's name to the Flash application. Flash
      // will call this handler using ExternalInterface.
      so.addVariable("callback", "assistiveTech.flashSuccess");
 
      // Try and write out the SWFObject
      var success = so.write(assistiveTech.replacementDiv);
 
      // If there's a problem in writing the tag, try to give the user more
      // information (they've probably got the wrong version of the player)
      if ( success )
      {
          // Successfully embedded. Now give the Flash movie focus
          // or else it will be ignored by the screen reader and not
          // get an update on isActive.
          document.getElementById("assistiveTechSwf").focus();
          if ( assistiveTech.debug ) {
            // Need to figure out what we want to do if debug is turned on and the flash piece succeeds
          }
      }
 
      else {
        // Embedding the Flash application failed. 
        // Display the version message in the assistiveTech div only
        // if we've been asked to do so.
        if ( assistiveTech.debug ) {
          var version = deconcept.SWFObjectUtil.getPlayerVersion();
          if (document.getElementById && (version.major > 0)) 
          {
            document.getElementById(assistiveTech.replacementDiv).innerHTML = "<p>This sample requires Flash Player version " +
                                                                         assistiveTech.requireVersion +
                                                                         ". You have Flash player " +
                                                                         version.major + "." + version.minor + "." + version.rev +
                                                                         " installed. <a href='http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash'>" +
                                                                         " Download the latest Flash Player</a> to run the sample.</p>";
          }
        }
        // Call the failure callback
        this [ assistiveTech.flashFailed ]();
      }
    }
  },
  setCookie: function() {
    var nextMonth = new Date();
    nextMonth.setSeconds(0);
    nextMonth.setMinutes(0);
    nextMonth.setHours(0);
    nextMonth.setMonth(nextMonth.getMonth() + 1);
    nextMonth.setDate(1);
    var expires_date = new Date( nextMonth );
    document.cookie = assistiveTech.cookieName + "=" + escape( assistiveTech.techAssist ) +
                      "; expires=" + expires_date.toGMTString() + 
                      "; path=/";
  },
  getCookie: function() {
    var cookies = document.cookie.split(';');
    for ( var i = 0; i < cookies.length; i++ ) {
      var cookieData = cookies[i].split('=');
      var cookieName = cookieData[0].replace(/^\s+|\s+$/g, '');
      if (cookieName === assistiveTech.cookieName) {	
        return cookieData;
      }
    }
    return false;
  },
  returnCookieValue: function() {
  	var cookieInformation = assistiveTech.getCookie();
	return cookieInformation[1];
  },
  cookieExists: function(){
  	var cookieInformation = assistiveTech.getCookie();
	if (assistiveTech.debug) {
		return false;
	}
	else if (cookieInformation && cookieInformation.length > 1) {
		return true;
	}
	return null;
  },
  debugCheck: function(debugFlag){
  	assistiveTech.debugFlag = debugFlag;
  	if (debugFlag === "on" || debugFlag === "off") {
		return true;
	}
	else {
		return false;
	}
  },
  flashSuccess: function(accessibilityFlag) {
    assistiveTech.techAssist = (assistiveTech.debug && assistiveTech.debugFlag === "on") ? true : ((assistiveTech.debug && assistiveTech.debugFlag ==="off") ? false : accessibilityFlag);
    assistiveTech.setCookie();
    var ATEnabled = assistiveTech.techAssist ? 'Yes' : 'No';
    // Add in your favorite Analytics software call here
  },
  flashFailed: function() {
    // Do something if the user doesn't have Flash 9 or higher installed
    if (assistiveTech.debug === "on") {
		alert('something went wrong');
	}
  }
};

var ParseQueryString = {
  params:{},
  init: function(qs) {
    if (!qs) { qs = location.search.substring(1, location.search.length); }
    if (qs.length === 0) { return; }
    // Turn <plus> back to <space>
    // See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
    qs = qs.replace(/\+/g, ' ');
    // parse out name/value pairs separated via &
    var args = qs.split('&');
    // split out each name=value pair
    for (var i = 0; i < args.length; i++) {
      var pair = args[i].split('=');
      var name = decodeURIComponent(pair[0]);
      var value = (pair.length === 2) ? decodeURIComponent(pair[1]) : name;
      this.params[name] = value;
    }
  },
  get: function(key, defaultText) {
	var value = ParseQueryString.params[key];
	return (value !== null) ? value : defaultText;
  },
  contains: function(key) {
	var value = ParseQueryString.params[key];
	return (value !== null);
 }
};

package {
  import flash.accessibility.Accessibility;
  import flash.display.LoaderInfo;
  import flash.display.Sprite;
  import flash.external.ExternalInterface;
 
  public class assistiveTech extends Sprite
  {
    public function assistiveTech()
    {
      var info : LoaderInfo = this.root.loaderInfo;
      var method : String = info.parameters.callback;
      if ( method && ExternalInterface.available )
      {
        ExternalInterface.call( method, Accessibility.active );
      }
    }
  }
}