Can I use HTML5 data-* attributes as boolean attributes?

Wesley Murch picture Wesley Murch · May 31, 2013 · Viewed 13.1k times · Source

I want to use a custom boolean attribute to mark an element's contents as editable. I'm aware of the data-* attributes, but wasn't sure if they require a value. I don't need data-is_editable="false", as the lack of the attribute would be equivalent. I only care if it's "true" (if the attribute exists). I know I can use other attributes like class but I don't want to as it seems slightly inappropriate (correct me if I'm wrong about that).

Here's the resource I'm reading, maybe it's the wrong document or I've overlooked the information I'm looking for: http://www.w3.org/html/wg/drafts/html/master/dom.html#custom-data-attribute

So for example, is this legal and valid?

<div data-editable data-draggable> My content </div>

Answer

Simon Boudrias picture Simon Boudrias · May 31, 2013

The example you show is valid. (Just like using disabled or checked in a form. Only xHTML force the presence of a value)

Although, the value returned is not a boolean. When you query this resource, you'll get an empty string for any empty data-* attributes.

Like so:

 domNode.dataset.draggable; // log ""
 domNode.dataset.notAdded; // log null

So, you just have to check it:

var isDraggable = (domNode.dataset.draggable != null)

Edit

Stupid to haven't tell it before. But, you can just check if the attribute exist if you want a boolean:

domNode.hasAttribute("data-draggable");