is there such a thing as an MXML interface

Question

This could potentially be a dumb question so apologies in advance if it is. I'm wondering if theres an equivilant of Interfaces in MXML?

Everytime I feel the need to use an interface I always wind up making an actionscript and not an MXML file because I don't know if / how you can.

For example I was going to have a component based on vbox. I have 4 different implementions of the same thing so I decided to use an interface. But instead of making a single MXML interface and implementing it I've created an interface in as3. I've implemented this interface in 4 different classes.

I then have made 4 different vbox containers each with one of the different implementations in the script tag.

Does this sound like a reasonable approach or am I going against the grain here?

EDIT -- adding examples

The interface

package components.content.contents
{
    public interface IContent
    {
        function init():void;
        function doSearch():void
        function setSearchTerm(term:String):void
    }
}

Implementation (1 of 4)

package components.content.contents
{
    public class ClipContent extends AbstractContent implements IContent
    {
        public function ClipContent()
        {
        }

        public function init():void
        {
        }

        public function doSearch():void
        {
        }

        public function setSearchTerm(term:String):void
        {
        }

    }
}

MXML File (1 of 4)

<?xml version="1.0" encoding="utf-8"?>
<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml" width="400" height="300">
        <mx:Script>
            <![CDATA[
                              // ClipContent Container
                import components.content.contents.ClipContent;
                public var content:ClipContent= new ClipContent()

                public function dostuff():void

                {
                  content.init()
                  content.doSearch()

                }
            ]]>
        </mx:Script>

</mx:VBox>

Answer 1

You can use interfaces with MXML components this way:

// YourClass.mxml
<mx:HBox implements="IYourInterface">

is an MXML equivalent of

// YourClass.as
class YourClass extends HBox implements IYourInterface

But you still need to create the interface (in this example IYourInterface) in Actionscript.

Answer 2

MXML can implement an interface, like Robert Bak said, but it cannot define an interface.