Add a data attribute to an UIComponent with `<tc:dataAttribute/>`. The data attribute is added to the parent and can be used by scripts.

Each box contains a panel with a data attribute. It contains a color code which will be used by a JavaScript which is included into this page. Click in the content area of the boxes to set up a color. Doubleclick to remove it.

    <tc:box label="Green">
      <tc:panel>
        <tc:style customClass="demo-data-attribute"/>
        <tc:dataAttribute name="color" value="#00ff00"/>
        ...