Setting up the Node

First we need to create an HTML element to make resizable.

<div id="demo">Resize Me</div>

Next, we give that element some CSS to make it visible.

#demo {
    height: 100px;
    width: 100px;
    border: 1px solid black;
    background-color: #8DD5E7;
    position: relative;
    padding: 1em;
    margin: 2em;
}

Setting up the YUI Instance

We need to create our YUI instance and tell it to load the resize module; for this simple use case, we could also use the base-resize submodule.

YUI().use('resize');

Making the Node Resizable

Now that we have a YUI instance with the resize module, we need to instantiate the Resize instance on this Node.

YUI().use('resize', function(Y) {
    var resize = new Y.Resize({
        //Selector of the node to resize
        node: '#demo'
    });   
});

Upon instantiation, the element's drag handles will appear and the element is resizable via drag-and-drop.