Add and delete rows dynamically in an HTML table

- May 03, 2012

Explanation

A row is inserted at the end of the table using the insertRow method, and two cells are added. One cell has just text, and the other cell has an HTML input. There is more than one way to accomplish this. The technique here uses document.createTextNode and document.createElement to create the text and HTML input, respectively.

If you enter text into the text boxes, they are not affected when new rows are added. Each row gets a unique name, so if the values are being submitted to a server-side page, it can look for txtRow1, txtRow2, etc.

The Remove button deletes the last row using table method deleteRow. The JavaScript does a check to prevent the header or first row from being deleted.

The JavaScript

// Last updated 2006-02-21
function addRowToTable()
{
  var tbl = document.getElementById('tblSample');
  var lastRow = tbl.rows.length;
  // if there's no header row in the table, then iteration = lastRow + 1
  var iteration = lastRow;
  var row = tbl.insertRow(lastRow);
  
  // left cell
  var cellLeft = row.insertCell(0);
  var textNode = document.createTextNode(iteration);
  cellLeft.appendChild(textNode);
  
  // right cell
  var cellRight = row.insertCell(1);
  var el = document.createElement('input');
  el.type = 'text';
  el.name = 'txtRow' + iteration;
  el.id = 'txtRow' + iteration;
  el.size = 40;
  
  el.onkeypress = keyPressTest;
  cellRight.appendChild(el);
  
  // select cell
  var cellRightSel = row.insertCell(2);
  var sel = document.createElement('select');
  sel.name = 'selRow' + iteration;
  sel.options[0] = new Option('text zero', 'value0');
  sel.options[1] = new Option('text one', 'value1');
  cellRightSel.appendChild(sel);
}
function keyPressTest(e, obj)
{
  var validateChkb = document.getElementById('chkValidateOnKeyPress');
  if (validateChkb.checked) {
    var displayObj = document.getElementById('spanOutput');
    var key;
    if(window.event) {
      key = window.event.keyCode; 
    }
    else if(e.which) {
      key = e.which;
    }
    var objId;
    if (obj != null) {
      objId = obj.id;
    } else {
      objId = this.id;
    }
    displayObj.innerHTML = objId + ' : ' + String.fromCharCode(key);
  }
}
function removeRowFromTable()
{
  var tbl = document.getElementById('tblSample');
  var lastRow = tbl.rows.length;
  if (lastRow > 2) tbl.deleteRow(lastRow - 1);
}
function openInNewWindow(frm)
{
  // open a blank window
  var aWindow = window.open('', 'TableAddRowNewWindow',
   'scrollbars=yes,menubar=yes,resizable=yes,toolbar=no,width=400,height=400');
   
  // set the target to the blank window
  frm.target = 'TableAddRowNewWindow';
  
  // submit
  frm.submit();
}
function validateRow(frm)
{
  var chkb = document.getElementById('chkValidate');
  if (chkb.checked) {
    var tbl = document.getElementById('tblSample');
    var lastRow = tbl.rows.length - 1;
    var i;
    for (i=1; i<=lastRow; i++) {
      var aRow = document.getElementById('txtRow' + i);
      if (aRow.value.length <= 0) {
        alert('Row ' + i + ' is empty');
        return;
      }
    }
  }
  openInNewWindow(frm);
}


The HTML
<form action="tableaddrow_nw.html" method="get">
<p>
<input type="button" value="Add" onclick="addRowToTable();" />
<input type="button" value="Remove" onclick="removeRowFromTable();" />
<input type="button" value="Submit" onclick="validateRow(this.form);" />
<input type="checkbox" id="chkValidate" /> Validate Submit
</p>
<p>
<input type="checkbox" id="chkValidateOnKeyPress" checked="checked" /> Display OnKeyPress
<span id="spanOutput" style="border: 1px solid #000; padding: 3px;"> </span>
</p>
<table border="1" id="tblSample">
  <tr>
    <th colspan="3">Sample table</th>
  </tr>
  <tr>
    <td>1</td>
    <td><input type="text" name="txtRow1"
     id="txtRow1" size="40" onkeypress="keyPressTest(event, this);" /></td>
    <td>
    <select name="selRow0">
    <option value="value0">text zero</option>
    <option value="value1">text one</option>
    </select>
    </td>
  </tr>
</table>
</form>

Tags : HTML Rows, Html, Table rows

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