YUI Library Examples: Drag & Drop: Dragged Element on Top

Basic Drag and Drop

The YUI Drag and Drop Utility lets you make HTML elements draggable.

For this example, we will enable drag and drop for the three <div> elements.

Create the demo elements:


1	<div id="dd-demo-1" class="dd-demo"></div>
2	<div id="dd-demo-2" class="dd-demo"></div>
3	<div id="dd-demo-3" class="dd-demo"></div>
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Next, we define a custom drag and drop implementation that extends YAHOO.util.DD. Drag and drop exposes many interesting moments that you can use to implement custom functionality. In this example, we override the startDrag and endDrag moments to adjust the z-index property so that the dragged element is always on top.


1	<script type="text/javascript">
2
3	// Our custom drag and drop implementation, extending YAHOO.util.DD
4	YAHOO.example.DDOnTop = function(id, sGroup, config) {
5	YAHOO.example.DDOnTop.superclass.constructor.apply(this, arguments);
6	};
7
8	YAHOO.extend(YAHOO.example.DDOnTop, YAHOO.util.DD, {
9	origZ: 0,
10
11	startDrag: function(x, y) {
12	YAHOO.log(this.id + " startDrag", "info", "example");
13
14	var style = this.getEl().style;
15
16	// store the original z-index
17	this.origZ = style.zIndex;
18
19	// The z-index needs to be set very high so the element will indeed be on top
20	style.zIndex = 999;
21	},
22
23	endDrag: function(e) {
24	YAHOO.log(this.id + " endDrag", "info", "example");
25
26	// restore the original z-index
27	this.getEl().style.zIndex = this.origZ;
28	}
29	});
30
31	</script>
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Now we create the instances of YAHOO.example.DDOnTop, passing the element ids or references for our demo elements.


1	<script type="text/javascript">
2
3	(function() {
4
5	var dd, dd2, dd3;
6	YAHOO.util.Event.onDOMReady(function() {
7	dd = new YAHOO.example.DDOnTop("dd-demo-1");
8	dd2 = new YAHOO.example.DDOnTop("dd-demo-2");
9	dd3 = new YAHOO.example.DDOnTop("dd-demo-3");
10	});
11
12	})();
13
14	</script>
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Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.

YUI Library Examples: Drag & Drop: Dragged Element on Top

Basic Drag and Drop

Configuration for This Example

YUI Logger Output:

Logger Console

Drag & Drop Examples:

More Drag & Drop Resources: