Consider a web page where you display a list of values in a tabular format. Assume that each row in that table has a check box either as a first or last element. You may be faced with a requirement to select/deselect all the check boxes. Use the following JSP code which uses java scrip to select/deselect check boxes.
<%@page import="java.util.ArrayList" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<title>CheckBox Example</title>
</head>
<body>
<h1>CheckBox Example</h1>
<%
List langLst = new ArrayList();
langLst.add("Java");
langLst.add("C");
langLst.add("C++");
langLst.add("Small Talk");
langLst.add("C#");
request.setAttribute("langLst",langLst);
%>
<form>
<input type=checkbox name='selectAllCheck' onClick='javascript:funcSelectAll()' value='Select All'>Select All </input>
<TABLE border="1">
<tr>
<th>
<B>Programming Language List </B>
</th>
</tr>
<c:forEach var="item" items="${requestScope.langLst}">
<tr>
<td>
<input type=checkbox name='lang' ><c:out value="${item}" /> </input>
</td>
</tr>
</c:forEach>
</form>
</body>
<script language="javascript">
function funcSelectAll()
{
if(document.forms[0].selectAllCheck.checked==true)
{
for (var a=0; a < document.forms[0].lang.length; a++) {
document.forms[0].lang[a].checked = true;
}
}
else
{
for (var a=0; a < document.forms[0].lang.length; a++) {
document.forms[0].lang[a].checked = false;
}
}
}
</script>
</html>
The above JSP code uses scriptlet code only for example purpose. In real world applications use either JSP standard tags or Expression language.