/***
 *  wForms 3.0 - a javascript extension to web forms.
 * 
 *  Customization Script:
 *    Clear the value of fields inside an switched off element .
 * 
 * 
 *  wForms 3.0 uses base2 - copyright 2007 Dean Edwards 
***/

if (typeof(wFORMS) == "undefined") {
	throw new Error("wFORMS core not found. This behavior depends on the wFORMS core.");
}
if (typeof(wFORMS.behaviors['switch']) == "undefined") {
	throw new Error("wFORMS switch behavior not found. This behavior depends on the wFORMS switch behavior.");
}

	wFORMS.behaviors['switch'].blacklist = {"tfa_resumeLater":""};

/**
 * Handler for the 'switchOff' event.
 */
new function(_) {
	// preserve any existing handler
	if(wFORMS.behaviors['switch'].onSwitchOff)
		var _onSwitchOff = wFORMS.behaviors['switch'].onSwitchOff;
		
	wFORMS.behaviors['switch'].onSwitchOff = function(element) {			
		// clear field values
		if( !(element.id in wFORMS.behaviors['switch'].blacklist) ){
			wFORMS.helpers.clearFieldValues(element);
		}
		// run any other existing handler
		if (_onSwitchOff) _onSwitchOff(element);
	}
	
	if(wFORMS.behaviors['switch'].onSwitchOn)
		var _onSwitchOn = wFORMS.behaviors['switch'].onSwitchOn;
		
	wFORMS.behaviors['switch'].onSwitchOn = function(element) {
		
		// Get form element, necessary to retrieve calculation instance.
		if(element.form) {
			var f = element.form;
		} else {
			var f=element;		
			while(f && f.tagName!='FORM') {
				f = f.parentNode;
			}
		}
		
		if(f) {
			// If calculation behavior is set, run it to update dependant formulas			
			var b = wFORMS.getBehaviorInstance(f,"calculation");
			if(b) {
				if(element.form) {
					// Update formula for the switch target.				
					b.refresh(null,element);	
				} else {
					// Update formula for nested elements.
					var cn = element.getElementsByTagName('*');
					
					for(i=0,l=cn.length;i<l;i++) {
						var n=cn[i];
						if(n.tagName=='INPUT' || n.tagName=='SELECT' || n.tagName=='TEXTAREA') {
							b.refresh(null,n);
						}
					}
				}
			}
		}	
		// run any other existing handler
		if (_onSwitchOn) _onSwitchOn(element);
	}
	
	
}();

/**
 * Helper method to clear field values (walking down the node tree recursively)
 * @param	DOMElement	the element clear
 */		
wFORMS.helpers.clearFieldValues = function(element) {
	if(!element || (element.id in wFORMS.behaviors['switch'].blacklist)) return;
	
	switch(element.tagName) {
		case "INPUT":
			if(element.type=='checkbox' || element.type=='radio') {
				if (element.checked) element.checked = false;
			} else //  if(element.type!='hidden') skip hidden fields?
				element.value = "";					
			break;
		case "SELECT":
			// clear the selected attribute for all options in the select.			 				
			for(var i=0;i<element.options.length;i++) {
				if(element.options[i].selected) {
					element.options[i].selected = false;
				}
			}
			if(element.options[0].value=='') {
				// No value is defined for the first option. 
				// We assume it to be of the 'Please select...' kind and 
				// we can safely revert to it.				
				element.selectedIndex = 0;
				element.options[0].selected = true;
			} else {
				// Otherwise, clear the selection altogether.
				element.selectedIndex = -1;
			}
			break;
		case "TEXTAREA":
			element.value = "";
			break;
		default:
			for (var i=0, l=element.childNodes.length;i<l;i++) {
				if(element.childNodes[i].nodeType==1)
					wFORMS.helpers.clearFieldValues(element.childNodes[i]);
			} 
			break;
	}	
	if(element.form) {
		// If calculation behavior is set, run it to update dependant formulas
		var b = wFORMS.getBehaviorInstance(element.form,"calculation");
		if(b) {
			b.run(null,element);	
		}
		// If switch behavior is set, run it to update dependant switches
		var _b = wFORMS.getBehaviorInstance(element.form,"switch");
		if(_b){
		//TODO: Check for infinite loop of triggers
			_b.run(null,element);
		}
	}		
}

/**
 * Can be used to update a calculated field if the run method is not triggered. 
 * @param {event} event
 * @param {domElement} elem
 */
if(wFORMS.behaviors.calculation) {
	wFORMS.behaviors.calculation.instance.prototype.refresh = function(event, element) { 
		
		for(var i=0; i<this.calculations.length;i++) {		
			var calc = this.calculations[i];
						
			if(element==calc.field) {
				this.compute(calc);
			}
		}
	} 
}