A data-* attribute on an <ol> tag attaches additional data to the ordered list.
To create a custom attribute, replace * with a lowercase string, such as data-id, data-status, or data-location.
A custom data-title attribute on an ordered list.
The attribute value is not visible, but it is readable by JavaScript.
<ol data-title="List of location">
<li>Amsterdam</li>
<li>London</li>
<li>Berlin</li>
<li>Paris</li>
</ol>
The data-* attribute adds custom information to an <ol> element.
The * part is replaced with a lowercase string, such as data-id, data-cost, or data-location.
An <ol> element can have any number of data-* attributes, each with their own name.
Using data-* attributes reduces the need for requests to the server.
Note: The data-* attribute is not visible and does not change the appearance of the ol.
<ol data-*="value">
Note: The * can be any string, such as data-id, data-cost, data-supplier, etc.
| Value | Description |
|---|---|
| value | A string value. Can be numeric, alphanumeric, JSON, etc. |
A custom data-content attribute on an <ol> element.
Clicking the button will display the content value.
<ol id="myol" data-content="List of cities">
<li>Amsterdam</li>
<li>London</li>
<li>Berlin</li>
<li>Paris</li>
</ol>
<br/>
<button onclick="show();">Show data</button>
<script>
let show = () => {
let element = document.getElementById("myol");
alert("Content = " + element.getAttribute('data-content'));
}
</script>
The <ol> tag has a custom data-content attribute.
The data-content attribute stores the content of the ordered list.
Clicks are handled by the onclick event.
Onclick invokes a JavaScript function that extracts and displays the <ol> content.
Note: Notice how the title displays immediately without server call.
Here is when data-* support started for each browser:
 Chrome
|
1.0 | Sep 2008 |
 Firefox
|
1.0 | Sep 2002 |
 IE/Edge
|
1.0 | Aug 1995 |
 Opera
|
1.0 | Jan 2006 |
 Safari
|
1.0 | Jan 2003 |
Back to <ol>
