Checkbox validation in Javascript

Question

Hello All I am having 2 groups of checkboxes which are been generated dynamically through java depending the code generator tool generate the following HTML

I am having the following JS to validate that atleast one of the checkbox is been selected from the each row which is not working I know if we give the same name it would work , just wanted to check if there is any work around for this with the name been changed

I cannot use JQUERY due to certain limitations

function validate()
{
      var e = document.form.elements;
    for ( var elem, i = 0; ( elem = e[i] ); i++ )
    {
         if (  elem.type == 'checkbox' )
        {
            if (!checkCheckBox (form, elem))
            {
                alert('Please check atleast one checkbox.');
                return false;
            } 
        } 
     } 
    document.form.submit();
    return true;
} 

 function checkCheckBox (form, elem)
{
     var check= form.elements[elem.name];
     var flag = false;
     for (var i=0; i <check.length; i++)
    {
        //alert(" radios[i].checked "+elem[i].checked);
        if (check[i].checked)
        {
             flag = true;
             break;
        }
    }
}





    <form name="form"> 
<table>
 <tr bgcolor='lightgray' width='100%' colspan='3'><td>KS3 QCheckbox 1</td></tr><tr><td>
<input type="checkbox" name="form[checkbox][KS31][KS31 1][]" id="COption 1" value="Option 1" /> 
<input type="checkbox" name="form[checkbox][KS31][KS32 1][]" id="COption 2" value="Option 2" /> 
<input type="checkbox" name="form[checkbox][KS31][KS33 1][]" id="COption 3" value="Option 3" /> 

<tr bgcolor='lightgray' width='100%' colspan='3'><td>KS3 QCheckbox 2</td></tr><tr><td>
<input type="checkbox" name="form[checkbox][KS32][KS31 2][]" id="COption 1" value="Option 1" /> 
<input type="checkbox" name="form[checkbox][KS32][KS32 2][]" id="COption 2" value="Option 2" /> 
<input type="checkbox" name="form[checkbox][KS32][KS33 2][]" id="COption 3" value="Option 3" /> 

<input type="submit" onClick="validate()">
</table>
</form>

Why can't you use JQuery? What are the limitations? Just curious. — jamesmortensen
– jamesmortensen, Commented Jan 5, 2011 at 2:28
I am using this scripts on Blackbery 5 and Blackberry 5 does not supports JQUERY we are using Rhodes framework — Ameya Thakur
– Ameya Thakur, Commented Jan 5, 2011 at 16:34

jamesmortensen · Accepted Answer · 2011-01-05 02:30:42Z

2

I think your checkCheckBox function must return the contents of the variable "flag":

function checkCheckBox (form, elem)
{
   var check= form.elements[elem.name];
   var flag = false;
   for (var i=0; i <check.length; i++)
   {
     //alert(" radios[i].checked "+elem[i].checked);
     if (check[i].checked)
        {
         flag = true;
         break;
        }
   }
   return flag;  // return true or false
}

answered Jan 5, 2011 at 2:30

jamesmortensen

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1 Comment

Ameya Thakur Over a year ago

The problem here is the grouping of the checkbox I want to validate the 1st Group of checkbox which are defined by name <br> form[checkbox][KS31] so that atleast one of the checkbox is selected the problem with the above loop is that it would iterate through all the checkboxes and if any one of the checkbox is not checked it would still throw the exception that you need to select atleast one checkbox

Tomasz Kowalczyk · Accepted Answer · 2014-04-29 09:15:09Z

-1

var chk = document.getElementsByName('checkbox_name[]');
   var len = chk.length;
   var has_program = false;
 for(i=0;i<len;i++) {
     if(chk[i].checked) {
        has_program = true;
        break;    
      } 
}
 if( !has_program )
    {
           alert("field with * is required");
         return false;
    }

edited Apr 29, 2014 at 9:15

Tomasz Kowalczyk

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answered Apr 29, 2014 at 8:36

Hussain

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