Editing WoW:XML/Anchor (section)

=== Default References ===

This is one of those things you wish you could explain at the beginning, but needs to be at the end. :)

Each of these are, in the general case, equivalient:
<pre>
<[[XML/Anchor|Anchor]] point="TOPLEFT" />
</pre>
<pre>
<[[XML/Anchor|Anchor]] point="TOPLEFT" relativeTo="$parent" />
</pre>
<pre>
<[[XML/Anchor|Anchor]] point="TOPLEFT" relativeKey="$parent" />
</pre>

In each case the relative frame is parent. For the default case, the relative frame its the parent. For 'relativeTo', a named parent frame's full name will replace '$parent' causing 'relativeTo' to refer to the parent frame by name. For 'relativeKey', the named or unnamed parent frame's Lua 'reference' will be used as the relative frame, similar to 'self.GetParent()'.

However as of 5.2, this will bug and *not* be equivalent of either '$parent' or 'self':

 <[[XML/Anchor|Anchor]] point="TOPLEFT" relativeKey="" />

In this case will ignore all size and anchors, and act as though layout was 'setallpoints' with this frame same size and position as parent,

Also, as of 5.2, May 13 2013, following may/will crash WoW:

 <[[XML/Anchor|Anchor]] point="TOPLEFT" relativeKey="$parent.$parent.AccidentallyOnUIParent" />

Where Frame is top frame with no parent and contains a LayerFrame with above anchor, which would effectivly be asking for key on parent of UIParent, since the frame is using the default parent. This is exceedingly easy to accidentally set, or move a frame where some child asks UIParent instead of intended parents parent. So: <Frame><Layers><Layer><Texture><Anchors><Anchor ...CENTER relativeKey=$parent.$parent.Key"/>... will crash, but not <Frame><Frames><Frame><Layers><Layer><Texture><Anchors><Anchor ...CENTER relativeKey=$parent.$parent.$parent.Key"/>... or <Frame parent="UIParent"><Layers><Layer><Texture><Anchors><Anchor ...CENTER relativeKey=$parent.$parent.$parent.Key"/>... and it doesnt matter in any of the cases if the key exists or not.

And finally, for 'relativeTo' below, in the case where the immediate parent doesn't actually have a 'name':

 <[[XML/Anchor|Anchor]] point="TOPLEFT" relativeTo="$parent" />

... will *not* be equivalient to:

 <[[XML/Anchor|Anchor]] point="TOPLEFT" />

... and will look for a parent with a name up the hierarchy until finds, or hits UIParent which is always named.