AWUI - a simple web user interface library with AJAX support

////////////////////////////////////////////////////////////
// AWUI - a web user interface - supports IE5+, Firefox, Opera 9
var AWUI_IS_IE = (document.all != undefined && typeof(ActiveXObject) != "undefined");
var AWUI_IS_OPERA = (navigator.userAgent.toLowerCase().indexOf("opera") > -1 || (document.all != undefined && !AWUI_IS_IE));
var AWUI_IS_MOZILLA = (!AWUI_IS_OPERA && !AWUI_IS_IE);
var AWUI_ID_DELIM = "#";

// create one global library
var AWUI = {
	AWUI_KEY: "AWUI Common",
	IS_IE : AWUI_IS_IE,
	IS_OPERA : AWUI_IS_OPERA,
	IS_MOZILLA : AWUI_IS_MOZILLA,
	
	// [[ config 
	ID_PREFIX : "awui",
	ID_DELIM : AWUI_ID_DELIM,
	ID_DELIM_RE : new RegExp(AWUI_ID_DELIM,"ig"),
	THROW_ERRORS : true,
	// ]]
	
		
	// [[ error codes
	ERROR_UNKNOWN : 0, 			// E_FAIL
	ERROR_OBJECT : 1, 			// E_POINTER
	ERROR_INVALID_VALUE : 2, 	// E_INVALIDARG
	ERROR_DOM : 3,
	ERROR_XML : 4,
	ERROR_RUNTIME : 10,
	// ]]
	
	// [[ strings
	STR_AWUI_ERROR : "AWUI Error",
	STR_ERR_UNKNOWN : "Unknown error",
	// ]]
	
	extend: function (subclass_, superclass_) {
	    var f = function() {};
	    f.prototype = superclass_.prototype;
	    subclass_.prototype = new f();
	    subclass_.prototype.constructor = subclass_;
	    subclass_.superclass = superclass_.prototype;
	    if (superclass_.prototype.constructor === Object.prototype.constructor)
	    	superclass_.prototype.constructor = superclass_;
	},

	// common functions set
	isEmpty: function (var_) { 
		var res = false;
		try { res = (var_ == undefined || var_ == null || var_ == ""); } catch (ex) { res = false; }
		return res; 
	},
	isFunction: function (obj_)	{ 
		return (typeof(obj_) == "function");
	},
	push: function (ar_, el_)	{ 
		if(ar_ && (typeof(ar_) == "object") && (typeof(ar_.length) != "undefined") ) 
			ar_[ar_.length] = el_;
	},
	
	// DOM interaction
	el: function (id_)	{ 
		return document.getElementById (id_); 
	},
	gvar: function (name_)	{ 
		if (this.isEmpty(name_)) return null;
		eval("var res = window." + name_);
		return res; 
	},
	wr: function (str_)	{ 
		try {
			document.write (str_); 
		} catch (e) {
			var msg = this.getErrorDesc (e);
			this.processError( this.AWUI_KEY + ": " + msg, this.ERROR_DOM);
		}
	},
	crel: function (type_) { 
		return document.createElement (type_);
	},
	crtext: function(str_) { 
		return document.createTextNode (str_);
	},
	crimg: function (src_, id_, w_, h_, alt_) { 
		var img = document.createElement ("IMG");
		img.border = 0;	var arg = arguments;
		if (arg.length == 0) return img;	img.src = src_;
		if (arg.length == 1) return img;	img.id = id_;
		if (arg.length == 2) return img;	img.width = w_;	
		if (arg.length == 3) return img;	img.height = h_;		
		if (arg.length == 4) return img;	img.alt = alt_;	
		return img;
	},
	
	preloadImg: function (src_)	{	
		if (!src_) return;
		var i = new Image(); i.src = src_;
	},
	preloadImages: function (ar_, path_)	{	
		if (!ar_ || !ar_.length) return;
		if (this.isEmpty(path_)) path_ = "";
		for (key in ar_)
			this.preloadImg (path_ + ar_[key]);
	},
	absPos: function (obj_)	{
		var res = { left : 0, res : 0 };
		if (!obj_) return res;
		res.left = parseInt(obj_.offsetLeft);	res.top = parseInt(obj_.offsetTop);
		var prnt = obj_.offsetParent;
		while (prnt) {	res.left += prnt.offsetLeft;	res.top += prnt.offsetTop;	prnt = prnt.offsetParent;	}
		return res;
	},

	appendRow: function (tbl_, pos_)	{	
		if (this.isEmpty(pos_)|| parseInt(pos_) < 0) pos_=-1;	
		if (!tbl_ || !tbl_.tBodies)
			return;
		if (tbl_.tBodies.length == 0) tbl_.appendChild ( this.crel("TBODY"));
		var row = this.crel("TR"); var tBody = tbl_.tBodies[0]; var nRow=0;
		if (!tBody || !row) return null;
		if (pos_ == -1) {
			tBody.appendChild(row);
			return row;
		}
		for(var ndx=0; ndx<tBody.childNodes.length; ndx++) {
			if (pos_ == nRow) {
				tBody.insertBefore(row, tBody.childNodes[ndx]);
				return row;
			}	
			if ( String(tBody.childNodes[ndx].tagName).toUpperCase() == "TR") 
				nRow++;
		}
		return row;
	},
	// events processing
	stopPropagation: function(e_) {
		if (e_ && e_.stopPropagation) e_.stopPropagation(); 
		if (e_ && e_.preventDefault) e_.preventDefault(); 
		if (window.event) window.event.cancelBubble = true;
		return false;
	},
	getKeyCode : function (e_) {
		return parseInt(e_ ? e_.which : window.event.keyCode);
	},
	srcEl: function (e_) {
		if (this.IS_IE)	
			return (e_ ? e_.srcElement : (window.event ? window.event.srcElement : null) );
		else	
			return (e_ ? e_.target : null);
	},
	setUnselectable: function (obj_) {
		if (obj_ && obj_.style)	{
			obj_.setAttribute("UNSELECTABLE","on"); 
			obj_.style.MozUserSelect = "none"; 
		}

	},
	
	// quotation
	quoteXml : function(s_)	{	
		return String (s_).replace (/&/g, "&amp;").replace (/</g, "&lt;").replace (/>/g, "&gt;");	
	},

	// WUI utility
	getWuiObj: function (id_) {
		if (this.isEmpty (id_)) return null;
		eval("var obj = window." + String(id_).split (this.ID_DELIM_RE)[0]);
		return obj;
	},
		
	processError: function (message_, code_) {
		if (code_ == undefined) code_ = 0;
		var e = new Error (code_, message_);
		e.description = e.message = message_;	
		e.number = e.code = code_;	
		e.name = this.STR_AWUI_ERROR;
		if (this.THROW_ERRORS)
			throw e;
		else
			alert (e.name + ": " + (message_ ? message_ : "Unknown") );
	},

	getErrorDesc: function (ex) {
		if (this.isEmpty(ex))
			return this.STR_ERR_UNKNOWN;
		var msg;
		if (this.IS_OPERA) {
			msg = ex.code + ", " + ex.message;
		} else if (this.IS_IE) {
			msg = ex.number + ", " + ex.description;
		} else {
			msg = String (ex);
		}
		return msg;
	}
	
};

// aObject - base class for all WUI components
// all its methods should be called through "aObject.prototype."
function aObject() {
	this.id = aObject.prototype.generateId();
	this.base = null;
	// register as global
	eval("window." + this.id + "=this");
};

aObject.prototype = {
	AWUI_KEY: "aObject",
	
	processError: function (obj_, message_, code_) {
		return AWUI.processError( ( !AWUI.isEmpty (obj_.AWUI_KEY) ? obj_.AWUI_KEY : aObject.prototype.AWUI_KEY) + ": " + message_, code_);
	},

	generateId: function () {
		var ndx = 1, id;
		while ( AWUI.gvar(id = AWUI.ID_PREFIX+""+ndx) ) ++ndx;
		return id;
	},
	
	// custom errors
	processError_CreateBase: function (obj_) {
		return AWUI.processError( ( (!AWUI.isEmpty (obj_.AWUI_KEY) ?  obj_.AWUI_KEY : aObject.prototype.AWUI_KEY)) + 
			": Invalid object base - cannot create DOM object", AWUI.ERROR_OBJECT);
	},

	processError_DuplicateObject: function (obj_) {
		return AWUI.processError( ( (!AWUI.isEmpty (obj_.AWUI_KEY) ?  obj_.AWUI_KEY : aObject.prototype.AWUI_KEY)) + 
			": Invalid name - element with the same name already exists", AWUI.ERROR_OBJECT);
	}

}