/*===================================================================
 Author: Matt Kruse
 
 View documentation, examples, and source code at:
     http://www.JavascriptToolbox.com/

 NOTICE: You may use this code for any purpose, commercial or
 private, without any further permission from the author. You may
 remove this notice from your final code if you wish, however it is
 appreciated by the author if at least the web site address is kept.

 This code may NOT be distributed for download from script sites, 
 open source CDs or sites, or any other distribution method. If you
 wish you share this code with others, please direct them to the 
 web site above.
 
 Pleae do not link directly to the .js files on the server above. Copy
 the files to your own server for use with your site or webapp.
 ===================================================================*/
// Constructor
function CheckBoxGroup() {
	this.controlBox=null;
	this.controlBoxChecked=null;
	this.maxAllowed=null;
	this.maxAllowedMessage=null;
	this.masterBehavior="all";
	this.formRef=null;
	this.checkboxWildcardNames=new Array();
	this.checkboxNames=new Array();
	this.totalBoxes=0;
	this.totalSelected=0;
	// Public methods
	this.setControlBox=CBG_setControlBox;
	this.setMaxAllowed=CBG_setMaxAllowed;
	this.setMasterBehavior=CBG_setMasterBehavior;	// all, some
	this.addToGroup=CBG_addToGroup;
	// Private methods
	this.expandWildcards=CBG_expandWildcards;
	this.addWildcardCheckboxes=CBG_addWildcardCheckboxes;
	this.addArrayCheckboxes=CBG_addArrayCheckboxes;
	this.addSingleCheckbox=CBG_addSingleCheckbox;
	this.check=CBG_check;
	}

// Set the master control checkbox name
function CBG_setControlBox(name) { this.controlBox=name; }

// Set the maximum number of checked boxes in the set, and optionally
// the message to popup when the max is reached.
function CBG_setMaxAllowed(num,msg) {
	this.maxAllowed=num;
	if (msg!=null&&msg!="") { this.maxAllowedMessage=msg; }
	}

// Set the behavior for the checkbox group master checkbox
//	All: all boxes must be checked for the master to be checked
//	Some: one or more of the boxes can be checked for the master to be checked
function CBG_setMasterBehavior(b) { this.masterBehavior = b.toLowerCase(); }

// Add checkbox wildcards to the checkboxes array
function CBG_addToGroup() {
	if (arguments.length>0) {
		for (var i=0;i<arguments.length;i++) {
			this.checkboxWildcardNames[this.checkboxWildcardNames.length]=arguments[i];
			}
		}
	}

// Expand the wildcard checkbox names given in the addToGroup method
function CBG_expandWildcards() {
	if (this.formRef==null) {alert("ERROR: No form element has been passed.  Cannot extract form name!"); return false; }
	for (var i=0; i<this.checkboxWildcardNames.length;i++) {
		var n = this.checkboxWildcardNames[i];
		var el = this.formRef[n];
		if (n.indexOf("*")!=-1) { this.addWildcardCheckboxes(n); }
		else if(CBG_nameIsArray(el)) { this.addArrayCheckboxes(n); }
		else { this.addSingleCheckbox(el); }
		}
	}


// Add checkboxes to the group which match a pattern
function CBG_addWildcardCheckboxes(name) {
	var i=name.indexOf("*");
	if ((i==0) || (i==name.length-1)) {
		searchString= (i)?name.substring(0,name.length-1):name.substring(1,name.length);
		for (var j=0;j<this.formRef.length;j++) {
			currentElement = this.formRef.elements[j];
			currentElementName=currentElement.name;
			var partialName = (i)?currentElementName.substring(0,searchString.length) : currentElementName.substring(currentElementName.length-searchString.length,currentElementName.length);
			if (partialName==searchString) {
				if(CBG_nameIsArray(currentElement)) this.addArrayCheckboxes(currentElement);
				else this.addSingleCheckbox(currentElement);
				}
			}
		}
	}

// Add checkboxes to the group which all have the same name
function CBG_addArrayCheckboxes(name) {
	if((CBG_nameIsArray(this.formRef[name])) && (this.formRef[name].length>0)) {
		for (var i=0; i<this.formRef[name].length; i++) { this.addSingleCheckbox(this.formRef[name][i]); }
		}
	}

function CBG_addSingleCheckbox(obj) {
	if (obj != this.formRef[this.controlBox]) {
		this.checkboxNames[this.checkboxNames.length]=obj;
		this.totalBoxes++;
		if (obj.checked) {
			this.totalSelected++;
			}
		}
	}

// Runs whenever a checkbox in the group is clicked
function CBG_check(obj) {
	var checked=obj.checked;
	if (this.formRef==null) {
		this.formRef=obj.form;
		this.expandWildcards();
		if (this.controlBox==null || obj.name!=this.controlBox) {
			this.totalSelected += (checked)?-1:1;
			}
		}
	if (this.controlBox!=null&&obj.name==this.controlBox) {
		if (this.masterBehavior=="all") {
			for (i=0;i<this.checkboxNames.length;i++) { this.checkboxNames[i].checked=checked; }
			this.totalSelected=(checked)?this.checkboxNames.length:0;
			}
		else {
			if (!checked) {
				obj.checked = (this.totalSelected>0)?true:false;
				obj.blur();
				}
			}
		}
	else {
		if (this.masterBehavior=="all") {
			if (!checked) {
				this.formRef[this.controlBox].checked=false;
				this.totalSelected--;
				}
			else { this.totalSelected++; }
			if (this.controlBox!=null) {
				this.formRef[this.controlBox].checked=(this.totalSelected==this.totalBoxes)?true:false;
				}
			}
		else {
			if (!obj.checked) { this.totalSelected--; }	
			else { this.totalSelected++; }
			if (this.controlBox!=null) {
				this.formRef[this.controlBox].checked=(this.totalSelected>0)?true:false;
				}
			if (this.maxAllowed!=null) {
				if (this.totalSelected>this.maxAllowed) {
					obj.checked=false;
					this.totalSelected--;
					if (this.maxAllowedMessage!=null) { alert(this.maxAllowedMessage); }
					return false;
					}
				}
			}
		}
	}

function CBG_nameIsArray(obj) {
	return ((typeof obj.type!="string")&&(obj.length>0)&&(obj[0]!=null)&&(obj[0].type=="checkbox"));
	}