hmc/js/utils.js - incubator-ambari - Git at Google


 var multipleClustersSupported = false;

 /* Super-handy augmentation to Function that allows 'this' to be bound
  * statically.
  *
  * Primarily used when creating objects whose methods will be used as
  * callbacks in unknown contexts.
  *
  * Look at txnUtils.js for sample usage.
  */
 Function.prototype.bind = function(scope) {
   var _function = this;

   return function() {
     return _function.apply(scope, arguments);
   }
 }

 /* Belongs with createInformationalPanel() */
 var customizedYuiPanelCss = false;

 /* XXX Ugly, ugly hack to emulate a singleton - users are NEVER supposed
  * to use this, and should only access the createInformationalPanel() and
  * destroyInformationalPanel() methods below.
  */
 var globalSingletonInformationalPanel;

 function createInformationalPanel( containerNodeId, headerContentString ) {

   /* XXX This should check that globalSingletonInformationalPanel is within
    * containerNodeId, and only then perform this cleanup, but this whole
    * panel-related section needs to be rewritten anyway - for now, we only
    * support the one globalSingletonInformationalPanel, and passing in
    * anything other than #informationalPanelContainerDivId as containerNodeId
    * is not guaranteed to work.
    */
   if( globalSingletonInformationalPanel ) {
     destroyInformationalPanel( globalSingletonInformationalPanel );
   }

   globalYui.one( containerNodeId ).append('<div id="informationalPanelInnerContainerDivId"></div>');

   var newPanel = new globalYui.Panel({
     srcNode: '#informationalPanelInnerContainerDivId',
     headerContent: headerContentString,
     width: 800,
     height: 400,
     render: true,
     modal: true,
     zIndex: 100,
     centered: true,
     visible: false
   });

   if( !customizedYuiPanelCss ) {
     /* Needs to be called one time only.
      *
      * We do this here instead of creating a static entry in a CSS file
      * because the first invocation of globalYui.Panel (above) pulls in all
      * the necessary additional styling information that is applied to the
      * panel - since this new styling information comes in at runtime, it
      * overrides any static CSS we might have had, so adding our overrides
      * at runtime (*after* globalYui.Panel) is the only way out.
      */
 	/*
     globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-hd', {
       background: 'rgb(50,185,50)',
       textAlign: 'center',
       fontWeight: 'bold',
       fontSize: '150%'
     });

     globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel .yui3-widget-hd .yui3-button-close', {
         border: 'medium solid gray',
         backgroundColor: 'white',
         height: '17px',
         width: '20px',
     });
     */

     // Temporary fix to a yui bug
     globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel .yui3-widget-hd .yui3-button-close:before', {
         content: 'url(../yui-3.5.1/build/assets/skins/sam/sprite_icons.png)',
         backgroundImage: 'url(../yui-3.5.1/build/assets/skins/sam/sprite_icons.png)',
     });
     /*
     globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-ft', {
       background: 'rgb(50,185,50)',
     });

     globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-ft .yui3-button', {
       fontWeight: 'bold',
       fontSize: '135%',
       color: 'white',
       margin: '0pt 6px',
       padding: '4px 8px',
       textDecoration: 'underline',
       background: 'none',
       border: '0px'
     });
     */

     customizedYuiPanelCss = true;
   }

   globalSingletonInformationalPanel = newPanel;

   return newPanel;
 }

 function destroyInformationalPanel( theInformationalPanelInstance ) {

   if( theInformationalPanelInstance ) {

     theInformationalPanelInstance.hide();
     theInformationalPanelInstance.destroy();

     if( theInformationalPanelInstance === globalSingletonInformationalPanel ) {
       globalSingletonInformationalPanel = null;
     }
   }
 }

 function showLoadingImg() {

   globalYui.one("#loadingDivId").setStyle('display','block');
   //globalYui.one("#blackScreenDivId").setStyle('display','block');
   //globalYui.one("#loadingImgId").setStyle('display','block');
 }

 function hideLoadingImg() {
   globalYui.one("#loadingDivId").setStyle('display','none');
   //globalYui.one("#loadingImgId").setStyle('display','none');
   //globalYui.one("#blackScreenDivId").setStyle('display','none');
 }

 function swapStageVisibilities( currentStageDivSelector, newStageDivSelector ) {

   globalYui.log("In swapStageVisibilities: " + currentStageDivSelector + "->" + newStageDivSelector);
   /* Hide the current stage. */
   globalYui.one(currentStageDivSelector).setStyle('display','none');

   /* Show the new stage. */
   globalYui.one(newStageDivSelector).setStyle('display','block');
 }

 /* TODO XXX Consider bundling the last 3 parameters into their own NewStage object.
  * TODO XXX Do the same for the first 2 parameters and a CurrentStage object.
  */
 function transitionToNextStage( currentStageDivSelector, currentStageData, newStageDivSelector, newStageData, newStageRenderFunction ) {

   clearFormStatus();

   globalYui.one(currentStageDivSelector).setStyle('display','none');

   /* Render the next stage. */
   newStageRenderFunction(newStageData);

   globalYui.log("In transitionToNextStage: " + currentStageDivSelector + "->" + newStageDivSelector);

   //// tshooter: No longer doing this given dynamic rendering on stages. Only hide current stage.
   /* And make it visibly replace the currently showing one. */
   ///// tshooter: commented: swapStageVisibilities(currentStageDivSelector, newStageDivSelector);

   /* And now, handle the updates to addNodesWizardStages... */

   /* There can be only one 'current' stage at a time. */
   var currentStage = globalYui.one('.installationWizardCurrentStage');

   if ( currentStage ) {
     var nextStage = null;

     /* Check to make sure we haven't reached the last stage. */
     if( nextStage = currentStage.next('.installationWizardUnvisitedStage') ) {

       /* Mark this up-until-now 'current' stage as 'visited'. */
       currentStage.replaceClass( 'installationWizardCurrentStage', 'installationWizardVisitedStage' );

       /* Mark the stage after that as the new 'current' stage. */
       nextStage.replaceClass( 'installationWizardUnvisitedStage', 'installationWizardCurrentStage' );
     }
   }
 }

 function clearFormStatus() {
   var formStatusDiv = globalYui.all("#formStatusDivId");
   // formStatusDiv.setContent("");
   formStatusDiv.setStyle("visibility", "hidden");
   formStatusDiv.setStyle("display", "none");
   formStatusDiv.set('className','');
   formStatusDiv.addClass("formStatusBar");
 }

 function setFormStatus(statusString, isError, noFade) {
   var formStatusDivCssClass;
   if (isError) {
     formStatusDivCssClass = 'statusError';
   } else {
     formStatusDivCssClass = 'statusOk';
   }
   var formStatusDiv = globalYui.all("#formStatusDivId");
   formStatusDiv.setStyle("visibility", "visible");
   formStatusDiv.setStyle("display", "block");
   formStatusDiv.set('className','');
   formStatusDiv.addClass("formStatusBar");
   formStatusDiv.addClass(formStatusDivCssClass);
   formStatusDiv.setContent(statusString);
   if (!isError && !noFade) {
     //setTimeout(fadeFormStatus, 1000);
   }
 }

 function fadeFormStatus() {
   var formStatusDiv = globalYui.one("#formStatusDivId");
   formStatusDiv.addClass("formStatusBarZeroOpacity");
 }

 function convertDisplayType (displayType) {
   switch (displayType) {
     case "NODISPLAY":
       return "NODISPLAY";

     case "TEXT":
       return "text";

     case "SECRET":
       return "password";

     case "ONOFF":
       return "checkbox";

     default:
       return "text";
   }
 }

 function executeStage(inputUrl, renderStageFunction) {
   globalYui.io(inputUrl, {
       method: 'GET',
       timeout : 10000,
       on: {
         success: function (x,o) {
           globalYui.log("RAW JSON DATA: " + o.responseText);
           // Process the JSON data returned from the server
           try {
             responseJson = globalYui.JSON.parse(o.responseText);
           }
           catch (e) {
             hideLoadingImg();
             alert("JSON Parse failed!");
             return;
           }

           globalYui.log("PARSED DATA: " + globalYui.Lang.dump(responseJson));

           if (responseJson.result != 0) {
              hideLoadingImg();
              // Error!
              alert("Got error during getting data: " + responseJson.error);
              return;
            }
           responseJson = responseJson.response;
           renderStageFunction(responseJson);
           hideLoadingImg();
           return;
         },
         failure: function (x,o) {
           alert("Async call failed!");
           return;
         }
       }
   });
 }

 function submitDataAndProgressToNextScreen(url, requestData, submitButton, thisScreenId, nextScreenId, nextScreenRenderFunction, errorHandlerFunction) {
   showLoadingImg();
   globalYui.io(url, {

       method: 'POST',
       data: globalYui.JSON.stringify(requestData),
       timeout : 10000,
       on: {
         start: function(x, o) {
           submitButton.set('disabled', true);
           globalYui.log("In start function");
           // showLoadingImg();
         },
         complete: function(x, o) {
           submitButton.set('disabled', false);
           globalYui.log("In stop function");
           // hideLoadingImg();
         },
         success: function (x,o) {
           submitButton.set('disabled', false);
           globalYui.log("RAW JSON DATA: " + o.responseText);

           // Process the JSON data returned from the server
           try {
             responseJson = globalYui.JSON.parse(o.responseText);
           }
           catch (e) {
             submitButton.set('disabled', false);
             hideLoadingImg();
             alert("JSON Parse failed!");
             return;
           }

           globalYui.log("PARSED DATA: " + globalYui.Lang.dump(responseJson));

           if (responseJson.result != 0) {
              submitButton.set('disabled', false);
              // Error!
              globalYui.log("Got error during submit data!" + responseJson.error);
              if ( errorHandlerFunction ) {
                globalYui.log("Invoking error handler function");
                errorHandlerFunction(responseJson);
              } else {
                alert("Got error during submit data!" + responseJson.error);
              }
              hideLoadingImg();
              return;
            }
           responseJson = responseJson.response;

           /* Done with this stage, transition to the next. */
           transitionToNextStage( thisScreenId, requestData, nextScreenId, responseJson, nextScreenRenderFunction );
         },
         failure: function (x,o) {
           submitButton.set('disabled', false);
           alert("Async call failed!");
         }
       }
   });
 }

 function PeriodicDataPoller( dataSourceContext, responseHandler ) {

   this.dataSourceContext = dataSourceContext;

   /* Smoothe out the optional bits of this.dataSourceContext. */
   if( !this.dataSourceContext.pollInterval ) {
     /* How often we poll. */
     this.dataSourceContext.pollInterval = 5000;
   }
   if( !this.dataSourceContext.maxFailedAttempts ) {
     /* How many failed attempts before we stop polling. */
     this.dataSourceContext.maxFailedAttempts = 25;
   }

   this.responseHandler = responseHandler;

   /* Of course, we're not paused when we start off. */
   this.paused = false;

   this.dataSource = new globalYui.DataSource.IO ({
     source: this.dataSourceContext.source
   });

   this.dataSource.plug(globalYui.Plugin.DataSourceJSONSchema, {
     schema: this.dataSourceContext.schema
   });

   this.dataSourcePollFailureCount = 0;

   /* Set when start() is invoked. */
   this.dataSourcePollHandle = null;

   this.dataSourcePollRequestContext = {
     request: this.dataSourceContext.request,
     callback: {
       success: function (e) {

         /* Avoid race conditions in JS by not processing incoming responses
          * from the backend if the PDP is paused (which is our signal that
          * a previous response is still in the middle of being processed).
          */
         if( !(this.isPaused()) ) {
           /* Reset our failure count every time we succeed. */
           this.dataSourcePollFailureCount = 0;

           /* Invoke user-pluggable code. */
           if( this.responseHandler.success ) {
             this.responseHandler.success( e, this );
           }
         }
       }.bind(this),

       failure: function (e) {

         if( !(this.isPaused()) ) {
           ++this.dataSourcePollFailureCount;

           if( this.dataSourcePollFailureCount > this.dataSourceContext.maxFailedAttempts ) {

             /* Invoke user-pluggable code. */
             if( this.responseHandler.failure ) {
               this.responseHandler.failure( e, this );
             }

             /* No point making any more attempts. */
             this.stop();
           }
         }
       }.bind(this)
     }
   };
 }

 /* Start polling. */
 PeriodicDataPoller.prototype.start = function() {

   this.dataSourcePollHandle = this.dataSource.setInterval
     ( this.dataSourceContext.pollInterval, this.dataSourcePollRequestContext );
 }

 /* Stop polling. */
 PeriodicDataPoller.prototype.stop = function() {

   /* Always unPause() during stop(), so the next start() won't be neutered. */
   this.unPause();
   this.dataSource.clearInterval( this.dataSourcePollHandle );
 }

 /* When the PDP is paused, the polling continues on its regular fixed
  * interval, but this.responseHandler is not invoked, thus avoiding
  * a race condition (at least) in JS.
  *
  * TODO XXX Improve upon this to not even make calls to the backend
  * while not losing our periodicity.
  */
 PeriodicDataPoller.prototype.pause = function() {

   this.paused = true;
 }

 PeriodicDataPoller.prototype.unPause = function() {

   this.paused = false;
 }

 PeriodicDataPoller.prototype.isPaused = function() {

   return this.paused;
 }

 /* Perform a one-time poll.
  *
  * Meant to be used when the polling is not at a set frequency (as with the
  * start()/stop() pair), and is instead meant to be under explicit
  * control of the application.
  */
 PeriodicDataPoller.prototype.pollOnce = function() {

   globalYui.io(this.dataSourceContext.source + this.dataSourcePollRequestContext.request, {
     on: this.dataSourcePollRequestContext.callback
   });
 }

 function titleCase(word){
   return word.substr(0,1).toUpperCase() + word.substr(1).toLowerCase();
 }

 function generateHMCUrl( uriPath ) {

   var url = '';

   /* By default, go to the HMC home page. */
   uriPath = ( typeof uriPath == "undefined" ) ? '/hmc/html/index.php' : uriPath;

   var currentUrl = window.location.href;
   globalYui.log('Current URL: ' + currentUrl);
   var currentPathPos = currentUrl.indexOf(window.location.pathname);
   globalYui.log('Current Path Pos: ' + currentPathPos);

   if( -1 != currentPathPos ) {
     url = currentUrl.substr(0, currentPathPos) + uriPath;
   }

   return url;
 }

	var multipleClustersSupported = false;

	/* Super-handy augmentation to Function that allows 'this' to be bound
	* statically.
	*
	* Primarily used when creating objects whose methods will be used as
	* callbacks in unknown contexts.
	*
	* Look at txnUtils.js for sample usage.
	*/
	Function.prototype.bind = function(scope) {
	var _function = this;

	return function() {
	return _function.apply(scope, arguments);
	}
	}

	/* Belongs with createInformationalPanel() */
	var customizedYuiPanelCss = false;

	/* XXX Ugly, ugly hack to emulate a singleton - users are NEVER supposed
	* to use this, and should only access the createInformationalPanel() and
	* destroyInformationalPanel() methods below.
	*/
	var globalSingletonInformationalPanel;

	function createInformationalPanel( containerNodeId, headerContentString ) {

	/* XXX This should check that globalSingletonInformationalPanel is within
	* containerNodeId, and only then perform this cleanup, but this whole
	* panel-related section needs to be rewritten anyway - for now, we only
	* support the one globalSingletonInformationalPanel, and passing in
	* anything other than #informationalPanelContainerDivId as containerNodeId
	* is not guaranteed to work.
	*/
	if( globalSingletonInformationalPanel ) {
	destroyInformationalPanel( globalSingletonInformationalPanel );
	}

	globalYui.one( containerNodeId ).append('<div id="informationalPanelInnerContainerDivId"></div>');

	var newPanel = new globalYui.Panel({
	srcNode: '#informationalPanelInnerContainerDivId',
	headerContent: headerContentString,
	width: 800,
	height: 400,
	render: true,
	modal: true,
	zIndex: 100,
	centered: true,
	visible: false
	});

	if( !customizedYuiPanelCss ) {
	/* Needs to be called one time only.
	*
	* We do this here instead of creating a static entry in a CSS file
	* because the first invocation of globalYui.Panel (above) pulls in all
	* the necessary additional styling information that is applied to the
	* panel - since this new styling information comes in at runtime, it
	* overrides any static CSS we might have had, so adding our overrides
	* at runtime (after globalYui.Panel) is the only way out.
	*/
	/*
	globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-hd', {
	background: 'rgb(50,185,50)',
	textAlign: 'center',
	fontWeight: 'bold',
	fontSize: '150%'
	});

	globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel .yui3-widget-hd .yui3-button-close', {
	border: 'medium solid gray',
	backgroundColor: 'white',
	height: '17px',
	width: '20px',
	});
	*/

	// Temporary fix to a yui bug
	globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel .yui3-widget-hd .yui3-button-close:before', {
	content: 'url(../yui-3.5.1/build/assets/skins/sam/sprite_icons.png)',
	backgroundImage: 'url(../yui-3.5.1/build/assets/skins/sam/sprite_icons.png)',
	});
	/*
	globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-ft', {
	background: 'rgb(50,185,50)',
	});

	globalYui.StyleSheet('KewlApp').set( '.yui3-skin-sam .yui3-panel-content .yui3-widget-ft .yui3-button', {
	fontWeight: 'bold',
	fontSize: '135%',
	color: 'white',
	margin: '0pt 6px',
	padding: '4px 8px',
	textDecoration: 'underline',
	background: 'none',
	border: '0px'
	});
	*/

	customizedYuiPanelCss = true;
	}

	globalSingletonInformationalPanel = newPanel;

	return newPanel;
	}

	function destroyInformationalPanel( theInformationalPanelInstance ) {

	if( theInformationalPanelInstance ) {

	theInformationalPanelInstance.hide();
	theInformationalPanelInstance.destroy();

	if( theInformationalPanelInstance === globalSingletonInformationalPanel ) {
	globalSingletonInformationalPanel = null;
	}
	}
	}

	function showLoadingImg() {

	globalYui.one("#loadingDivId").setStyle('display','block');
	//globalYui.one("#blackScreenDivId").setStyle('display','block');
	//globalYui.one("#loadingImgId").setStyle('display','block');
	}

	function hideLoadingImg() {
	globalYui.one("#loadingDivId").setStyle('display','none');
	//globalYui.one("#loadingImgId").setStyle('display','none');
	//globalYui.one("#blackScreenDivId").setStyle('display','none');
	}

	function swapStageVisibilities( currentStageDivSelector, newStageDivSelector ) {

	globalYui.log("In swapStageVisibilities: " + currentStageDivSelector + "->" + newStageDivSelector);
	/* Hide the current stage. */
	globalYui.one(currentStageDivSelector).setStyle('display','none');

	/* Show the new stage. */
	globalYui.one(newStageDivSelector).setStyle('display','block');
	}

	/* TODO XXX Consider bundling the last 3 parameters into their own NewStage object.
	* TODO XXX Do the same for the first 2 parameters and a CurrentStage object.
	*/
	function transitionToNextStage( currentStageDivSelector, currentStageData, newStageDivSelector, newStageData, newStageRenderFunction ) {

	clearFormStatus();

	globalYui.one(currentStageDivSelector).setStyle('display','none');

	/* Render the next stage. */
	newStageRenderFunction(newStageData);

	globalYui.log("In transitionToNextStage: " + currentStageDivSelector + "->" + newStageDivSelector);

	//// tshooter: No longer doing this given dynamic rendering on stages. Only hide current stage.
	/* And make it visibly replace the currently showing one. */
	///// tshooter: commented: swapStageVisibilities(currentStageDivSelector, newStageDivSelector);

	/* And now, handle the updates to addNodesWizardStages... */

	/* There can be only one 'current' stage at a time. */
	var currentStage = globalYui.one('.installationWizardCurrentStage');

	if ( currentStage ) {
	var nextStage = null;

	/* Check to make sure we haven't reached the last stage. */
	if( nextStage = currentStage.next('.installationWizardUnvisitedStage') ) {

	/* Mark this up-until-now 'current' stage as 'visited'. */
	currentStage.replaceClass( 'installationWizardCurrentStage', 'installationWizardVisitedStage' );

	/* Mark the stage after that as the new 'current' stage. */
	nextStage.replaceClass( 'installationWizardUnvisitedStage', 'installationWizardCurrentStage' );
	}
	}
	}

	function clearFormStatus() {
	var formStatusDiv = globalYui.all("#formStatusDivId");
	// formStatusDiv.setContent("");
	formStatusDiv.setStyle("visibility", "hidden");
	formStatusDiv.setStyle("display", "none");
	formStatusDiv.set('className','');
	formStatusDiv.addClass("formStatusBar");
	}

	function setFormStatus(statusString, isError, noFade) {
	var formStatusDivCssClass;
	if (isError) {
	formStatusDivCssClass = 'statusError';
	} else {
	formStatusDivCssClass = 'statusOk';
	}
	var formStatusDiv = globalYui.all("#formStatusDivId");
	formStatusDiv.setStyle("visibility", "visible");
	formStatusDiv.setStyle("display", "block");
	formStatusDiv.set('className','');
	formStatusDiv.addClass("formStatusBar");
	formStatusDiv.addClass(formStatusDivCssClass);
	formStatusDiv.setContent(statusString);
	if (!isError && !noFade) {
	//setTimeout(fadeFormStatus, 1000);
	}
	}

	function fadeFormStatus() {
	var formStatusDiv = globalYui.one("#formStatusDivId");
	formStatusDiv.addClass("formStatusBarZeroOpacity");
	}

	function convertDisplayType (displayType) {
	switch (displayType) {
	case "NODISPLAY":
	return "NODISPLAY";

	case "TEXT":
	return "text";

	case "SECRET":
	return "password";

	case "ONOFF":
	return "checkbox";

	default:
	return "text";
	}
	}

	function executeStage(inputUrl, renderStageFunction) {
	globalYui.io(inputUrl, {
	method: 'GET',
	timeout : 10000,
	on: {
	success: function (x,o) {
	globalYui.log("RAW JSON DATA: " + o.responseText);
	// Process the JSON data returned from the server
	try {
	responseJson = globalYui.JSON.parse(o.responseText);
	}
	catch (e) {
	hideLoadingImg();
	alert("JSON Parse failed!");
	return;
	}

	globalYui.log("PARSED DATA: " + globalYui.Lang.dump(responseJson));

	if (responseJson.result != 0) {
	hideLoadingImg();
	// Error!
	alert("Got error during getting data: " + responseJson.error);
	return;
	}
	responseJson = responseJson.response;
	renderStageFunction(responseJson);
	hideLoadingImg();
	return;
	},
	failure: function (x,o) {
	alert("Async call failed!");
	return;
	}
	}
	});
	}

	function submitDataAndProgressToNextScreen(url, requestData, submitButton, thisScreenId, nextScreenId, nextScreenRenderFunction, errorHandlerFunction) {
	showLoadingImg();
	globalYui.io(url, {

	method: 'POST',
	data: globalYui.JSON.stringify(requestData),
	timeout : 10000,
	on: {
	start: function(x, o) {
	submitButton.set('disabled', true);
	globalYui.log("In start function");
	// showLoadingImg();
	},
	complete: function(x, o) {
	submitButton.set('disabled', false);
	globalYui.log("In stop function");
	// hideLoadingImg();
	},
	success: function (x,o) {
	submitButton.set('disabled', false);
	globalYui.log("RAW JSON DATA: " + o.responseText);

	// Process the JSON data returned from the server
	try {
	responseJson = globalYui.JSON.parse(o.responseText);
	}
	catch (e) {
	submitButton.set('disabled', false);
	hideLoadingImg();
	alert("JSON Parse failed!");
	return;
	}

	globalYui.log("PARSED DATA: " + globalYui.Lang.dump(responseJson));

	if (responseJson.result != 0) {
	submitButton.set('disabled', false);
	// Error!
	globalYui.log("Got error during submit data!" + responseJson.error);
	if ( errorHandlerFunction ) {
	globalYui.log("Invoking error handler function");
	errorHandlerFunction(responseJson);
	} else {
	alert("Got error during submit data!" + responseJson.error);
	}
	hideLoadingImg();
	return;
	}
	responseJson = responseJson.response;

	/* Done with this stage, transition to the next. */
	transitionToNextStage( thisScreenId, requestData, nextScreenId, responseJson, nextScreenRenderFunction );
	},
	failure: function (x,o) {
	submitButton.set('disabled', false);
	alert("Async call failed!");
	}
	}
	});
	}

	function PeriodicDataPoller( dataSourceContext, responseHandler ) {

	this.dataSourceContext = dataSourceContext;

	/* Smoothe out the optional bits of this.dataSourceContext. */
	if( !this.dataSourceContext.pollInterval ) {
	/* How often we poll. */
	this.dataSourceContext.pollInterval = 5000;
	}
	if( !this.dataSourceContext.maxFailedAttempts ) {
	/* How many failed attempts before we stop polling. */
	this.dataSourceContext.maxFailedAttempts = 25;
	}

	this.responseHandler = responseHandler;

	/* Of course, we're not paused when we start off. */
	this.paused = false;

	this.dataSource = new globalYui.DataSource.IO ({
	source: this.dataSourceContext.source
	});

	this.dataSource.plug(globalYui.Plugin.DataSourceJSONSchema, {
	schema: this.dataSourceContext.schema
	});

	this.dataSourcePollFailureCount = 0;

	/* Set when start() is invoked. */
	this.dataSourcePollHandle = null;

	this.dataSourcePollRequestContext = {
	request: this.dataSourceContext.request,
	callback: {
	success: function (e) {

	/* Avoid race conditions in JS by not processing incoming responses
	* from the backend if the PDP is paused (which is our signal that
	* a previous response is still in the middle of being processed).
	*/
	if( !(this.isPaused()) ) {
	/* Reset our failure count every time we succeed. */
	this.dataSourcePollFailureCount = 0;

	/* Invoke user-pluggable code. */
	if( this.responseHandler.success ) {
	this.responseHandler.success( e, this );
	}
	}
	}.bind(this),

	failure: function (e) {

	if( !(this.isPaused()) ) {
	++this.dataSourcePollFailureCount;

	if( this.dataSourcePollFailureCount > this.dataSourceContext.maxFailedAttempts ) {

	/* Invoke user-pluggable code. */
	if( this.responseHandler.failure ) {
	this.responseHandler.failure( e, this );
	}

	/* No point making any more attempts. */
	this.stop();
	}
	}
	}.bind(this)
	}
	};
	}

	/* Start polling. */
	PeriodicDataPoller.prototype.start = function() {

	this.dataSourcePollHandle = this.dataSource.setInterval
	( this.dataSourceContext.pollInterval, this.dataSourcePollRequestContext );
	}

	/* Stop polling. */
	PeriodicDataPoller.prototype.stop = function() {

	/* Always unPause() during stop(), so the next start() won't be neutered. */
	this.unPause();
	this.dataSource.clearInterval( this.dataSourcePollHandle );
	}

	/* When the PDP is paused, the polling continues on its regular fixed
	* interval, but this.responseHandler is not invoked, thus avoiding
	* a race condition (at least) in JS.
	*
	* TODO XXX Improve upon this to not even make calls to the backend
	* while not losing our periodicity.
	*/
	PeriodicDataPoller.prototype.pause = function() {

	this.paused = true;
	}

	PeriodicDataPoller.prototype.unPause = function() {

	this.paused = false;
	}

	PeriodicDataPoller.prototype.isPaused = function() {

	return this.paused;
	}

	/* Perform a one-time poll.
	*
	* Meant to be used when the polling is not at a set frequency (as with the
	* start()/stop() pair), and is instead meant to be under explicit
	* control of the application.
	*/
	PeriodicDataPoller.prototype.pollOnce = function() {

	globalYui.io(this.dataSourceContext.source + this.dataSourcePollRequestContext.request, {
	on: this.dataSourcePollRequestContext.callback
	});
	}

	function titleCase(word){
	return word.substr(0,1).toUpperCase() + word.substr(1).toLowerCase();
	}

	function generateHMCUrl( uriPath ) {

	var url = '';

	/* By default, go to the HMC home page. */
	uriPath = ( typeof uriPath == "undefined" ) ? '/hmc/html/index.php' : uriPath;

	var currentUrl = window.location.href;
	globalYui.log('Current URL: ' + currentUrl);
	var currentPathPos = currentUrl.indexOf(window.location.pathname);
	globalYui.log('Current Path Pos: ' + currentPathPos);

	if( -1 != currentPathPos ) {
	url = currentUrl.substr(0, currentPathPos) + uriPath;
	}

	return url;
	}