/**
*    Chained Selects for JQuery 
*    Copyright (C) 2007 Ziadin Givan www.CodeAssembly.com  
*
*    This program is free software: you can redistribute it and/or modify
*    it under the terms of the GNU General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU General Public License for more details.
*
*    You should have received a copy of the GNU General Public License
*    along with this program.  If not, see http://www.gnu.org/licenses/
*
*    
*   settings = { usePost : false, before:function() {}, after: function() {} }	
*   if usePost is true, then the form will use POST to pass the parameters to the target, otherwise will use GET
*   "before" function is called before the ajax request and "after" function is called after the ajax request
*
*/
jQuery.fn.chainSelect = function( target, url, settings ) 
{
  return this.each( function() {
	$(this).change( function( )  {
		if ( settings != undefined && settings.before != undefined ) {
			settings.before( target );
		}
		
   		ajaxCallback = function ( data, textStatus ) {
			$(target).html("");//clear old options
			data = eval(data);//get json array
			//iterate over all options
			for (i = 0; i < data.length; i++) {
				//get key => value
				for ( key in data[i] ) {
					$(target).get(0).add(new Option(data[i][key],[key]), document.all ? i : null); 
				}
			}

			if (settings != undefined && settings.after != undefined  )  {
				settings.after( target );
			}
	
			$(target).change();//call next chain
		};
	
		if ( settings != undefined && settings.usePost == true ) {
			$.post(url + $(this).val(), ajaxCallback);
		} else {
			$.get(url + $(this).val(), ajaxCallback);
		}
		$("option:first", target).attr( "selected", "selected" );//select first option
	});  
  });
};