/**
*    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 : true, before:function() {}, after: function() {}, parameters : { parameter1 : 'value1', parameter2 : 'value2'} }
*   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
*   You can specify additional parameters to be sent to the the server in settings.parameters.
*
*/
$.fn.chainSelect = function( target, url, settings )
{

	$(this).change( function ()
	{
		settings = jQuery.extend(
		{
			after : null,
			before : null,
			usePost : false,
			parameters : { '_id' :  $(this).attr('id'), '_name' : $(this).attr('name') },
			selectedInTarget : ''
		} , settings);
		settings.parameters._value =  $(this).val();

		if ( settings.before != null )
		{
			settings.before( target );
		}

		ajaxCallback = function ( data, textStatus )
		{
			$(target).html("");//clear old options
			opts = eval("(" + data + ")");//get json array
			if(opts){
				for (i = 0; i < opts.length; i++)//iterate over all options
				{
					for ( key in opts[i] )//get key => value
					{
						opt = new Option(opts[i][key],[key]);
						if(key == settings.selectedInTarget){
							$(opt).attr('selected', 'selected');
						}
						$(target).get(0).add(opt, document.all ? i : null);
					}
				}

				if (settings.after != null  )
				{
					settings.after( target, opts.length);
				}
				
			}
		};

		if ( settings.usePost == true )
		{
			$.post( url + '/' + settings.parameters._value, null, ajaxCallback );
		} else
		{
			$.get( url + '/' + settings.parameters._value, null, ajaxCallback );
		}


	});
};