// Functions for AjaxTabbedPanel
var AjaxTabbedPanel = {

	// Called to perform any onLoad function
	onLoad : function(elementID) {
		this.runOnLoad($(elementID));	
	},
	
    // Change which tab appears in selected state
    selectTab : function(tabControlID, selectedTabID, paneID, busyDivID) {
      var selectedTab = $(selectedTabID);
      var tablist = this.getChildrenByTagName($(tabControlID), 'li');
      var nodes = $A(tablist);

      nodes.each(function(node){
          $(node);  // Force prototype extension of node for IE 7
          if (node.id != selectedTab.id) {
              node.removeClassName('ajaxTabbedPanelTab-selected').addClassName('ajaxTabbedPanelTab-unselected');
          }
      });
      selectedTab.removeClassName('ajaxTabbedPanelTab-unselected').addClassName('ajaxTabbedPanelTab-selected');
      
      // Only call runOnSelect if the panel contents have previously been loaded.
      // If the panel contents are getting loaded the loadPanel function will call this
      var pane = $(paneID);
      if (pane.innerHTML!='' && pane.innerHTML!=this.busyContent(busyDivID))
          AjaxTabbedPanel.runOnSelect($(tabControlID)); 
    },

    // Change which panel appears
    selectPanel : function(paneControlID, selectedPaneID) {
      var selectedPane = $(selectedPaneID);
      
      // Tabs are hidden with display:none.  This removes the contents from the DOM... including any form fields.
      // The fields on any tab NOT selected since the last (non-Ajax)form submission will therefore not be sent 
      // to the app and WO will interpret this as null values.  To avoid problems from this, the relevant form is 
      // submitted before the tab is hidden.
      
      // First look for a form in each pane and if not found, look for one form wrapping the entire panel
      var formInPanel = selectedPane.down('form');
      if (formInPanel) {
      	ASB.request(formInPanel, null, {asynchronous:false, evalScripts:false, _asbn: 'dummy'});
      }
      else {
        var formAroundPanel = selectedPane.up('form');
	    if (formAroundPanel) {
	      ASB.request(formAroundPanel, null, {asynchronous:false, evalScripts:false, _asbn: 'dummy'});
	    }
      }

      var panelist = this.getChildrenByTagName($(paneControlID), 'li');
      var nodes = $A(panelist);

	   // Find the currently seleted tab, de-select it and notify the application  
      nodes.each(function(node){
        $(node);  // Force prototype extension of node for IE 7
        if (node.id != selectedPane.id) {
          if (node.hasClassName('ajaxTabbedPanelPane-selected')) {
            new Ajax.Request(node.getAttribute('updateUrl') + "?didSelect=false",  {asynchronous:true, evalScripts:false})
            node.removeClassName('ajaxTabbedPanelPane-selected').addClassName('ajaxTabbedPanelPane-unselected');
          }
        };
      });

      // Select the new tab and notify the app of the selected tab
      selectedPane.removeClassName('ajaxTabbedPanelPane-unselected').addClassName('ajaxTabbedPanelPane-selected');
      new Ajax.Request(selectedPane.getAttribute('updateUrl') + "?didSelect=true",  {asynchronous:true, evalScripts:false})
    },

    // Loads the panel contents if not already loaded
    loadPanel : function(tabControlID, paneID, busyDivID, shouldReload) {
      var pane = $(paneID);
      if (pane.innerHTML=='' || pane.innerHTML==this.busyContent(busyDivID) || shouldReload) {
         pe = new PeriodicalExecuter(function(pe) { pane.innerHTML=AjaxTabbedPanel.busyContent(busyDivID); pe.stop()}, 0.25);
         new Ajax.Updater(pane, pane.getAttribute('updateUrl'), {asynchronous: true, 
         														 evalScripts: true, 
         														 onComplete: function(a, b) {pe.stop(); 
         														                             AjaxTabbedPanel.runOnLoad(pane); 
         														                             AjaxTabbedPanel.runOnSelect($(tabControlID)); }});
      }
    },

    runOnLoad : function(element) {
    	var onLoadScript = element.getAttribute('onLoad');
		if (onLoadScript) {
			eval(onLoadScript);	
		}
    },
    
    runOnSelect : function(element) {
    	var onSelectScript = element.getAttribute('onSelect');
		if (onSelectScript) {
			eval(onSelectScript);	
		}
    },
        
    // Determines what to show if the panel takes a while to  load  
    busyContent : function(busyDivID) {
      var busyContent = 'Loading, please wait...';
      if (busyDivID != '') {
          busyContent = $(busyDivID).innerHTML;
      }
      return busyContent;
    },   
    
    // Returns an element's children that have a specific tag name as an array
    getChildrenByTagName : function(element, tag_name) {
        child_array      = new Array();
        tag_name         = tag_name.toLowerCase();
        element_children = element.childNodes;

        for (i = 0; i < element_children.length; i++) {
            if (element_children[i].tagName != undefined) {
                if (element_children[i].tagName.toLowerCase() == tag_name) {
                    child_array.push(element_children[i]);
                }
            }
        }

        return child_array;
    }
}