Metacat

/*

License: LGPL as per: http://www.gnu.org/copyleft/lesser.html

$Id$

*/

/** get a time stamp at start of the page load */

var mbTimerStart = new Date();

/** the global config object */

var config;

/** URL of Mapbuilder's lib/ directory. */

var baseDir;

/** mapbuilder environement settings, defaults to a .xml extension but is 

  auto-configured by the ant build script to .jsp for tomcat environment 

  the URL to this file will be pre-pended with the baseDir value.

*/

var mbServerConfig = "mapbuilderConfig.xml";

var mbNsUrl = "http://mapbuilder.sourceforge.net/mapbuilder";

// LoadState Constants

var MB_UNLOADED=0;    // Scripts not loaded yet

var MB_LOAD_CORE=1;   // Loading scripts loaded defined in Mapbuilder

var MB_LOAD_CONFIG=2; // Loading scripts loaded defined in Config

var MB_LOADED=3;      // All scripts loaded

/**

 * This Object bootstraps the Mapbuilder libraries by loading the core

 * script files.

 * When Config.js is loaded, the script files for objects described in the

 * Mapbuilder config file are loaded.

 * Objects which have dependencies will trigger the dependancies to load

 * when they are loaded.

 *

 * @constructor

 * @author Cameron Shorter

 * @requires Config

 * @requires Listener

 * @requires ModelBase

 * @requires Sarissa

 * @requires Util

 */

function Mapbuilder() {

  /**

   * Determines which Mapbuilder scripts are loading.

   * TBD: Is it possible to use enumerated types in JS?

   */

  this.loadState=MB_UNLOADED;

  /** Array of objects that are loading.  Don't continue initialisation until

   * all objects have loaded. */

  this.loadingScripts=new Array();

  /** Timer to periodically check if scripts have loaded. */

  this.scriptsTimer=null;

  /**

   * Called periodically and moves onto the next loadState when this round of

   * scripts have loaded.

   * For IE clients, object.readyState is used to check if scripts are loaded.

   * Mozilla works fine without this function - I think it is single threaded.

   */

  this.checkScriptsLoaded=function() {

    if (document.readyState!=null){

      // IE client

      // Scripts are removed from array when they have loaded

      while(this.loadingScripts.length>0

        &&(this.loadingScripts[0].readyState=="loaded"

          ||this.loadingScripts[0].readyState=="complete"

          ||this.loadingScripts[0].readyState==null))

      {

        this.loadingScripts.shift();

      }

      if (this.loadingScripts.length==0){

        this.setLoadState(this.loadState+1);

      }

    }

    else{

      // Mozilla client

      if(this.loadState==MB_LOAD_CORE && config!=null){

        // Config has finished loading

        this.setLoadState(MB_LOAD_CONFIG);

      }

    }

  }

  /**

   * Move onto loading the next set of scripts.

   * @param newState The new loading state.

   */

  this.setLoadState=function(newState){

    this.loadState=newState;

    switch (newState){

      case MB_LOAD_CORE:

        this.loadScript(baseDir+"/util/sarissa/Sarissa.js");

        //this.loadScript(baseDir+"/util/sarissa/sarissa_dhtml.js");

        this.loadScript(baseDir+"/util/sarissa/sarissa_ieemu_xpath.js");

        //this.loadScript(baseDir+"/util/sarissa/sarissa_ieemu_xslt.js");//all deprecated

        this.loadScript(baseDir+"/util/Util.js");

        this.loadScript(baseDir+"/util/Listener.js");

        this.loadScript(baseDir+"/model/ModelBase.js");

        this.loadScript(baseDir+"/model/Config.js");

        break;

      case MB_LOAD_CONFIG:

        if(document.readyState){

          // IE

          config=new Config(mbConfigUrl);

          config.loadConfigScripts();

        }else{

          // Mozilla

          this.setLoadState(MB_LOADED);

        }

        break;

      case MB_LOADED:

        clearInterval(this.scriptsTimer);

        break;

    }

  }

  /**

   * Dynamically load a script file if it has not already been loaded.

   * @param url The url of the script.

   */

  this.loadScript=function(url){

    if(!document.getElementById(url)){

      var script = document.createElement('script');

      script.defer = false;   //not sure of effect of this?

      script.type = "text/javascript";

      script.src = url;

      script.id = url;

      document.getElementsByTagName('head')[0].appendChild(script);

      this.loadingScripts.push(script);

    }

  }

  /**

   * Internal function to load scripts for components that don't have <scriptfile>

   * specified in the config file.

   * @param xPath Xpath match of components from the Config file.

   * @param dir The directory the script is located in.

   */

  this.loadScriptsFromXpath=function(nodes,dir) {

    //var nodes = this.doc.selectNodes(xPath);

    for (var i=0; i<nodes.length; i++) {

      if (nodes[i].selectSingleNode("mb:scriptFile")==null){

        scriptFile = baseDir+"/"+dir+nodes[i].nodeName+".js";

        this.loadScript(scriptFile);

      }

    }

  }

  //derive the baseDir value by looking for the script tag that loaded this file

  var head = document.getElementsByTagName('head')[0];

  var nodes = head.childNodes;

  for (var i=0; i<nodes.length; ++i ){

    var src = nodes.item(i).src;

    if (src) {

      var index = src.indexOf("/Mapbuilder.js");

      if (index>=0) {

        baseDir = src.substring(0, index);

      }

    }

  }

  // Start loading core scripts.

  this.setLoadState(MB_LOAD_CORE);

  // Start a timer which periodically calls checkScriptsLoaded().

  this.scriptsTimer=setInterval('mapbuilder.checkScriptsLoaded()',100);

}

/**

 * copied from sarissa, a function to check browser security setting in IE, 

 * opens a help page if ActiveX objects are disabled.

 */

function checkIESecurity()

{

  var testPrefixes = ["Msxml2.DOMDocument.5.0", "Msxml2.DOMDocument.4.0", "Msxml2.DOMDocument.3.0", "MSXML2.DOMDocument", "MSXML.DOMDocument", "Microsoft.XMLDOM"];

  // found progID flag

  var bFound = false;

  for(var i=0; i < testPrefixes.length && !bFound; i++) {

    try {

      var oDoc = new ActiveXObject(testPrefixes[i]);

      bFound = true;

    }

    catch (e) {

      //trap; try next progID

    }

  }

  if (!bFound) window.open("/mapbuilder/docs/help/IESetup.html");  //TBD: set this URL in config

}

if (navigator.userAgent.toLowerCase().indexOf("msie") > -1) checkIESecurity();

var mapbuilder=new Mapbuilder();

/**

 * Initialise Mapbuilder if script has been loaded, else wait to be called

 * again.

 */

function mapbuilderInit(){

  if(mapbuilder && mapbuilder.loadState==MB_LOADED){

    clearInterval(mbTimerId);

    config.parseConfig(config);

    config.callListeners("init");

    var mbTimerStop = new Date();

    //alert("load time:"+(mbTimerStop.getTime()-mbTimerStart.getTime()) );

    if (window.mbInit) window.mbInit();

    config.callListeners("loadModel");

  }

}

/** Timer used when checking if scripts have loaded. */

var mbTimerId;

/**

 * Mapbuilder's main initialisation script.

 * This should be called from the main html file using:

 *   <body onload="mbDoLoad()">

 * @param initFunction Optional - A function reference that will be called after 

 * config.init() has been called.  This is to give application code a chance to

 * do initialization and be guaranteed that all objects exist (inlcuding config).

 */

function mbDoLoad(initFunction) {

  // See if scripts have been loaded every 100msecs, then call config.init().

  mbTimerId=setInterval('mapbuilderInit()',100);

  if (initFunction) window.mbInit = initFunction;

}