Editing WoW:XML/Anchor (section)

=== Relative References ===
Frames can have names. This allows an 'anchor' to reference a frame by its name for relative layout using 'relativeTo'. The 'relativeTo' attribute can contain a replacable tag '$parent' for refereing to another frame without actually having to know its direct parents name, like '$parent3' would refrence 'Frame3' if the parent's name was 'Frame'. This is useful for allowing cleaner code, as parent frame's names could be changed without disturbing the layout. This is even more important with templates as a template may have no way of knowing its parents names and could still access known relative elements by name.

 <Frame name="FrameTemplate" virtual='true'>
   <Frames>
     <Frame name="$parent2">
       <Size x="100" y="100">
       <[[XML/Anchors|Anchors]]><[[XML/Anchor|Anchor]] point="TOP" relativePoint="BOTTOM" x="0" y="-10" /></Anchors>
     </frame>
     <Frame name="$parent3">
       <Size x="50" y="50">
       <[[XML/Anchors|Anchors]]><[[XML/Anchor|Anchor]] point="TOPLEFT" relativeTo="$parent2" /></Anchors>
     </frame>
   </Frames>
 </Frame>
 <Frame name="Frame" inherits="FrameTemplate" />

This works the same as the last example, but using a tmplate with all manner of relative anchors and names.

 <Frame name="FrameTemplate" virtual='true'>
   <Frames>
     <Frame parentKey="frame2">
       <Size x="100" y="100">
       <[[XML/Anchors|Anchors]]><[[XML/Anchor|Anchor]] point="TOP" relativePoint="BOTTOM" x="0" y="-10" /></Anchors>
     </frame>
     <Frame parentKey="frame3">
       <Size x="50" y="50">
       <[[XML/Anchors|Anchors]]><[[XML/Anchor|Anchor]] point="TOPLEFT" relativeKey="$parent.frame2" /></Anchors>
     </frame>
   </Frames>
 </Frame>
 <Frame name="Frame" inherits="FrameTemplate" />

This works the same as the last example, but using lua runtime based 'keys' instead of names.