CODEWITHSUNDEEP
c#javascriptasp.net
Jafry
Jafry

Reputation: 95

checkbox list -javascript

In my aspx page i am having a checkbox list ..It has binded values from a table.. I need to validate the checkbox list ..I tried the following script 

 var checkBoxCount = 0;     

        var elements = document.getElementById('<%=ChkBoxList.ClientID%>');

        for(i=0; i<elements.length;i++)

        {

        if(elements[i].checked) 

        checkBoxCount++;

        }  

        if (checkBoxCount == 0)
               {
                alert("Please choose atleast one");
              return false;
              }

But I can't get the required output, it requires to select all the values in the checkbox list ..My need is atleast only one item must be selected from the checkbox list.. Using javascript

Thanks in advance...

Upvotes: 1

Views: 2691

Answers (4)

Jafry
Jafry

Reputation: 95

var k=0; var ControlRef = document.getElementById('ChkBoxList'); var CheckBoxListArray = ControlRef.getElementsByTagName('input'); for (var i=0; i

Upvotes: 0

dogbane
dogbane

Reputation: 274838

You will have to show us your generated html.

However, here is a working example:

<html>
<body><form name="myform" method="POST" action="" onsubmit="return validate();">
<input type="checkbox" name="mybox" value="1" /> 1 
<input type="checkbox" name="mybox" value="2" /> 2 
<input type="checkbox" name="mybox" value="3" /> 3 
<input type="checkbox" name="mybox" value="4" /> 4 
<input type="checkbox" name="mybox" value="5" /> 5 
<input type="submit" value="Submit Form" />
</form>

<script type = "text/javascript">
function validate() {
    var checkBoxCount = 0;
    for (var i = 0; i< 5; i++) {
        if(document.myform["mybox"][i].checked){
            checkBoxCount ++;
        }
    }
    if (checkBoxCount == 0) {
        alert ("Tick a box!");
        return false;
    }
    return true;
}
</script>
</body>
</html>

Upvotes: 0

KhanZeeshan
KhanZeeshan

Reputation: 1410

function readListControl()
{
 var tableBody = document.getElementById('CheckBoxList1').childNodes[0];

 for (var i=0;i<tableBody.childNodes.length; i++)
 {
  var currentTd = tableBody.childNodes[i].childNodes[0];
  var listControl = currentTd.childNodes[0];

  if ( listControl.checked == true )
   alert('#' + i + ': is checked');
 }
}

Upvotes: 1

Robusto
Robusto

Reputation: 31913

document.getElementById returns an element, not an array.

One way to do this would be to get the container and iterate through the inputs, like so:

var container = document.getElementById('<%=ChkBoxList.ClientID%>').parentNode;
var inputs = container.getElementsByTagName('input');

for (var i=0; i<inputs.length; i++) {
  if (typeof inputs[i] = "checkbox") {
    // statements
  }
}

You may also want to qualify the inputs with more conditional statements. This just gives you the broad brush strokes.

Upvotes: 0

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