/* helpers */
// source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf
// Production steps of ECMA-262, Edition 5, 15.4.4.14
// Reference: http://es5.github.io/#x15.4.4.14
if (!Array.prototype.indexOf) {
Array.prototype.indexOf = function (searchElement, fromIndex) {
var k;
// 1. Let O be the result of calling ToObject passing
// the this value as the argument.
if (this == null) {
throw new TypeError('"this" is null or not defined');
}
var O = Object(this);
// 2. Let lenValue be the result of calling the Get
// internal method of O with the argument "length".
// 3. Let len be ToUint32(lenValue).
var len = O.length >>> 0;
// 4. If len is 0, return -1.
if (len === 0) {
return -1;
}
// 5. If argument fromIndex was passed let n be
// ToInteger(fromIndex); else let n be 0.
var n = +fromIndex || 0;
if (Math.abs(n) === Infinity) {
n = 0;
}
// 6. If n >= len, return -1.
if (n >= len) {
return -1;
}
// 7. If n >= 0, then Let k be n.
// 8. Else, n<0, Let k be len - abs(n).
// If k is less than 0, then let k be 0.
k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
// 9. Repeat, while k < len
while (k < len) {
// a. Let Pk be ToString(k).
// This is implicit for LHS operands of the in operator
// b. Let kPresent be the result of calling the
// HasProperty internal method of O with argument Pk.
// This step can be combined with c
// c. If kPresent is true, then
// i. Let elementK be the result of calling the Get
// internal method of O with the argument ToString(k).
// ii. Let same be the result of applying the
// Strict Equality Comparison Algorithm to
// searchElement and elementK.
// iii. If same is true, return k.
if (k in O && O[k] === searchElement) {
return k;
}
k++;
}
return -1;
};
}
// source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim
if (!String.prototype.trim) {
(function () {
// Make sure we trim BOM and NBSP
var rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
String.prototype.trim = function () {
return this.replace(rtrim, '');
};
})();
}
// source: http://toddmotto.com/apollo-js-standalone-class-manipulation-api-for-html5-and-legacy-dom/
function hasClass(elem, className) {
if (elem.classList) {
return elem.classList.contains(className);
} else {
return new RegExp('(^|\\s)' + className + '(\\s|$)').test(elem.className);
}
}
function addClass(elem, className) {
if (!hasClass(elem, className)) {
if (elem.classList) {
elem.classList.add(className);
} else {
elem.className += (elem.className ? ' ' : '') + className;
}
}
}
function removeClass(elem, className) {
if (hasClass(elem, className)) {
if (elem.classList) {
elem.classList.remove(className);
} else {
elem.className = elem.className.replace(new RegExp('(^|\\s)*' + className + '(\\s|$)*', 'g'), '');
}
}
}
/* example code */
var rows = document.getElementsByTagName('tbody')[0].getElementsByTagName('tr');
var groups = [],
item, itemName;
for (var i = 0, l = rows.length; i < l; i++) {
item = rows[i].getElementsByTagName('td')[0];
itemName = item.innerText.trim();
if (groups.indexOf(itemName) !== -1) {
addClass(rows[i], 'group-element');
} else {
groups.push(itemName);
addClass(rows[i], 'group-root');
addClass(rows[i], 'group-element');
if (item.addEventListener) { // For all major browsers, except IE 8 and earlier
item.addEventListener("click", toggleGroup);
} else if (x.attachEvent) { // For IE 8 and earlier versions
item.attachEvent("onclick", toggleGroup);
}
}
}
function toggleGroup(evt) {
var tr = evt.target.parentNode,
isVisible = !hasClass(tr, 'group-element');
do {
if (tr.nodeType === 1) {
isVisible ? addClass(tr, 'group-element') : removeClass(tr, 'group-element');
}
tr = tr.nextSibling;
} while (tr && !hasClass(tr, 'group-root'));
}
.group-element {
display: none;
}
.visible-row, .group-root {
display: table-row;
}
<table>
<thead>
<tr>
<th>Users</th>
<th>Day</th>
<th>Hours</th>
<th>Desc</th>
<th>Department</th>
<th>Task</th>
<th>Subtask</th>
</tr>
</thead>
<tbody>
<tr>
<td>user 1</td>
<td>2015-02-11 13:05:00</td>
<td>2.0</td>
<td>blabla</td>
<td>Standard</td>
<td>testing</td>
<td>testen</td>
</tr>
<tr>
<td>user 1</td>
<td>2015-03-11 13:05:00</td>
<td>1.0</td>
<td>blbla</td>
<td>Standard</td>
<td>making coffee</td>
<td>get milk</td>
</tr>
<tr>
<td>peter</td>
<td>2015-03-11 13:05:00</td>
<td>1.0</td>
<td>padsfs</td>
<td>something</td>
<td>PB</td>
<td>test</td>
</tr>
</tbody>
</table>