What to use as base for a custom MXML component?

Question

I'm using several custom MXML components in my Flex 4.5 application.

They all use absolute coordinates to place Image, Label, Line, etc. components and are currently based on a spark.components.BorderContainer:

<?xml version="1.0" encoding="utf-8"?>
<s:BorderContainer
    xmlns:fx="http://ns.adobe.com/mxml/2009" 
    xmlns:s="library://ns.adobe.com/flex/spark" 
    xmlns:mx="library://ns.adobe.com/flex/mx" 
    width="160" height="140" borderWeight="0" 
    creationComplete="init(event)">

    <s:layout>
        <s:BasicLayout />
    </s:layout>

    <s:Image id="_avatar" x="0" y="0" width="160" height="120" />
    <s:Label id="_username" x="1" y="122" width="80" /> 
    <s:Label id="_bid" x="80" y="122" width="40" textAlign="center" /> 
    <s:Label id="_trix" x="120" y="122" width="36" textAlign="right" />
        .... and so on: Images, Labels, Paths, Lines, Rects .... 
</s:BorderContainer>

Then I've realized, that I probably don't have to use BorderContainer, because I don't draw/need any borders around my custom components.

But I don't know, what to take instead of it.

I've tried taking <mx:UIComponent> (and removing <s:Layout> tag above), but then I get the error:

'Image' declaration must be contained within the <Declarations> tag since it does not implement 'mx.core.IUIComponent'.
'Label' declaration must be contained within the <Declarations> tag since it does not implement 'mx.core.IUIComponent'.

Any suggestions please? Is there some simplest possible spark "container"? And do I need a "container" at all if I use (and want to use) absolute coordinates?

Answer 1

I recommend you to use s:Group. And you can omit layout declaration as far as BasicLayout is default layout.

UIComponent isn't container so it hasn't default placeholder for children to add them with MXML.