Jquery using .on to sum a repeatable list

Question

I think this is a jquery specific question, but I am using wordpress with the gravity forms plugin. I have a list type with three columns and repeatable rows with class .add_list_item to add a row and .delete_list_item to delete a row. Field code is:

<li id='field_21_42' class='gfield    conest' >
  <label class='gfield_label' for='input_21_42'>Three Column List</label>
  <div class='ginput_container ginput_list'>
    <table class='gfield_list'>
      <colgroup><col id='gfield_list_42_col1' class='gfield_list_col_odd'></col><col id='gfield_list_42_col2' class='gfield_list_col_even'></col><col id='gfield_list_42_col3' class='gfield_list_col_odd'></col></colgroup>
      <thead><tr><th>Option</th><th>Value</th><th>Notes</th><th>&nbsp;</th></tr></thead>
        <tbody>
          <tr class='gfield_list_row_odd'>
          <td class='gfield_list_cell gfield_list_42_cell1'>
            <select name='input_42[]' tabindex='25' >
              <option value='' >Select Option</option>
              <option value='Option 1' >Option 1</option>
              <option value='Option 2' >Option 2</option>
              <option value='Option 3' >Option 3</option>
              <option value='Option 4' >Option 4</option>
            </select>
          </td>
          <td class='gfield_list_cell gfield_list_42_cell2'>
            <input type='text' name='input_42[]' value='' tabindex='26'/>
          </td>
          <td class='gfield_list_cell gfield_list_42_cell3'>
            <input type='text' name='input_42[]' value='' tabindex='27'/>
          </td>
          <td class='gfield_list_icons'>
            <img src='/wp-content/plugins/gravityforms/images/add.png' class='add_list_item '  title='Add a row' alt='Add a row' onclick='gformAddListItem(this, 0)' style='cursor:pointer; margin:0 3px;' />
            <img src='/wp-content/plugins/gravityforms/images/remove.png'  title='Remove this row' alt='Remove this row' class='delete_list_item' style='cursor:pointer; visibility:hidden;' onclick='gformDeleteListItem(this, 0)' />
          </td>
        </tr>
      </tbody>
    </table>
  </div>
</li>

I used some javascript to populate another field with id=input_21_41. The javascript code I used was:

<script type="text/javascript">
  jQuery(document).ready(function ($) {
    var values = $("input[type='text'][name='input_42[]']").change(function() {
      var sum = 0;
      values.each(function() { // Step through each one
        var value = parseInt($(this).val(), 10); // Retrieve its numeric value
        sum += (isNaN(value) ? 0 : value); // Add to the total
      });
      $('#input_21_41').val(sum); // And show the average
    });
  });
</script>

It works great, but only copies the first row of column 2 into #input_21_41. I was told that I need to use .on to add/remove additional values:

$( '#input_21_42' ).on( 'click', '.add_list_item', function(){
  // do stuff here
});

I'm having trouble figuring out how to properly write this out, so I can account for adding and removing, and then the sum .onchange. Can anyone help me out?

Answer 1

I think, you made typo in id name. That is id will have name as field_21_42 instead of input_21_42.

$( '#field_21_42' ).on( 'click', '.add_list_item', function(){ ..