Question

Html multiple select box with struts

Asked by: meena_r

Hi,
I have two html select box for selecting templated for a user. one select box have static values and another one has the value when user clicks on add button to add options from static select box. I am using javascript to perform "Add" and "Remove" function. Now I want to get value of the second select box inside my action class for processing. I have created a form bean which takes String [ ] and get set methods for the same. However I am not able to get the values in action class. My action class throws nullpointer exception. (See the code snippet)

Please help. Thanks in advance.

JSP
<table>
    <tr><td>
        <select id="userPrincipals" multiple="multiple" size="8" name="userPrincipals">
        <option value="----" disabled="disabled">  - - Access Assigned to User - -  </option>
	</select>
    </td>
    <td>
        <table>
            <tr><td><input type="button" value="&lt; &lt; add" onclick="javascript:addPrincipal(this.form.principals, this.form.userPrincipals);" />
        </td></tr>
        <tr><td><input type="button" value="remove &gt; &gt;" onclick="javascript:removePrincipal(this.form.userPrincipals, this.form.principals);" />
        </td></tr>
     </table>
    <td>
	<select id="principals" multiple="multiple" size="8">
            <option value="----" disabled="disabled">- - Available Operations and Access - - </option>
	    <option>Adminstrator</option>
            <option>Configuration</option>
            <option>Group</option>
            <option>NCS</option>
            <option>NMS</option>
            <option>Operator</option>
            <option>Operation</option>
            
        </select> 
     </td></tr>
   </table>
 
JavaScript
 
<script type="text/javascript">
 
function save(){
	var prinNames = document.getElementById('userPrincipals');
	var strUserPrincipals="";
	for(var r=1;r<prinNames.options.length;r++){
	     strUserPrincipals += prinNames.options[r].value+"§";
	}
         document.forms[0].userPrincipalsNames.value=strUserPrincipals;
	document.forms[0].submit();
    }
	
function addPrincipal(var1, var2){
	moveOptions(var1, var2);
   }
 
function removePrincipal(var1, var2){
         moveOptions(var1, var2);
    }
 
function addOption(theSel, theText, theValue){
	var newOpt = new Option(theText, theValue);
	var selLength = theSel.length;
	theSel.options[selLength] = newOpt;
    }
 
function deleteOption(theSel, theIndex){
	var selLength = theSel.length;
	if(selLength>0)	{
	    theSel.options[theIndex] = null;
	   }
     }
 
function moveOptions(theSelFrom, theSelTo){
	var selLength = theSelFrom.length;
	selectedText = new Array();
	selectedValues = new Array();
	var selectedCount = 0;
         var i;
	
         // Find the selected Options in reverse order
	// and delete them from the 'from' Select.
	for(i=selLength-1; i>=0; i--)
	{
	   if(theSelFrom.options[i].selected){
	   selectedText[selectedCount] = theSelFrom.options[i].text;
	   selectedValues[selectedCount] = theSelFrom.options[i].value;
	   deleteOption(theSelFrom, i);
	   selectedCount++;
	 }
        }
	
// Add the selected text/values in reverse order.
// This will add the Options to the 'to' Select
// in the same order as they were in the 'from' Select.
for(i=selectedCount-1; i>=0; i--){
	addOption(theSelTo, selectedText[i], selectedValues[i]);
      }
    }
 
</script>
 
 
Form Bean
private String [] userPrincipals;
public String [] getUserPrinciples() {
        System.out.println("Getting userPrinciple's value"+ userPrincipals);
        return userPrincipals;
    }
 
    public void setUserPrinciples(String [] userPrincipals) {
        System.out.println("setting user principle value");
        this.userPrincipals = userPrincipals;
    }
 
Action class
 
public ActionForward execute(ActionMapping mapping, ActionForm  form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        System.out.println("inside execute of AdduserAction");
        AddUserForm userForm = new AddUserForm();
      //  System.out.println("userform's length"+ userForm.getSelected().length);
       System.out.println("userform's length"+ userForm.getUserPrinciples().length);
        
        return mapping.findForward(SUCCESS);
        
    }

                                  
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Asked On
2008-02-15 at 11:38:43ID23167050
Topics

Jakarta Struts

,

JavaScript

,

Java Server Pages (JSP)

Participating Experts
2
Points
500
Comments
4

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Answers

 

Accepted Solution

by: JSasePosted on 2008-02-16 at 01:02:14ID: 20908921

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Assisted Solution

by: karanwPosted on 2008-02-18 at 02:07:19ID: 20918767

Rank: Guru

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