<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
 <%@ taglib prefix="n" uri="neo"%>
 <%@ taglib prefix="t" uri="template"%>
 
 <t:listagem>
 	<%-- Isso força o formulário ser limpo no servidor --%>
 	<input type="hidden" name="clearFilter" value="true"/> 
 	
 	<t:janelaFiltro>
 		<t:tabelaFiltro>
 			<t:property name="filtrarPor" type="select-one" includeBlank="false"/>
 			<t:property name="descricao"/>
 			<t:property name="piezometro"/>
 		</t:tabelaFiltro>
 	</t:janelaFiltro>
 	<t:janelaResultados>
 		<t:tabelaResultados>
 			<t:property name="id" />
 			<t:property name="descricao" />
 			<t:property name="piezometro" />
 		</t:tabelaResultados>
 	</t:janelaResultados>
 </t:listagem>
 
 <script type="text/javascript">
 	
 	function Filter(row, input, label){
 		this.row = row;
 		this.input = input;
 		this.label = label;
 	}
 	
 	function registrarFiltros(){
 		var filtrarPor = document.forms[0].filtrarPor;
 		var table = findTable(filtrarPor);
 		var filters = findFilters(table);
 		
 		for(var i = 0; i < filters.length; i++){
 			var filter = filters[i];
 			var op = new Option(filter.label,filter.input.name);
 			op.filter = filter;
 			filtrarPor.options.add(op);
 			if(filter.input.name == '${param.filtrarPor}'){
 				filtrarPor.selectedIndex = i;
 			}
 		}
 		
 		filtrarPor.onchange = function(){
 			var selectedOp = filtrarPor.options[filtrarPor.selectedIndex];
 			for(var i = 0; i < filters.length; i++){
 				var filter = filters[i];
 				if(filter == selectedOp.filter){
 					filter.input.disabled = false;					
 					filter.row.style.display = '';
 				} else {
 					filter.input.disabled = true;
 					filter.row.style.display = 'none';					
 				}
 			}
 		};
 		
 		filtrarPor.onchange();
 	}
 	
 	/*
 	 * Acha a tabela imediatamente superior
 	 */
 	function findTable(obj){
 		while(obj && obj.tagName && obj.tagName.toLowerCase() != 'table'){
 			obj = obj.parentNode;
 		}
 		return obj;
 	}
 	
 	function findFilters(table) {
 		var rows = table.rows;
 		var filters = new Array();
 		for(var i = 1; i < rows.length; i++){
 			var row = rows[i];
 			var input = findInput(row.cells[1]); //o input tem que estar no segundo TD
 			var label = row.cells[0].innerHTML;
 			filters.push(new Filter(row, input, label));
 		}
 		return filters;
 	}
 	
 	function findInput(cell){
 		//achar o input
 		var childs = cell.childNodes;
 		for(var i = 0; i < childs.length; i++){
 			var child = childs[i];
 			if(child.tagName && (child.tagName.toLowerCase() == 'input' || child.tagName.toLowerCase() == 'select')){
 				return child;
 			}
 		}
 	}
 	
 	registrarFiltros();
 </script>