I've created a theme package called hoi with a default theme. In the app/design/frontend/hoi/default/etc/theme.xml I've set a parent theme to be the a theme we purchased called blacknwhite.
This almost works but it does not pick up the layout.xml from the blacknwhite theme as my own theme's xml overwrites it. It works when I copy and paste the contents from the blacknwhite theme's xml into my own theme's xml. But I would rather not do this as so I tried to create a new layout update in my theme's theme.xml.
theme.xml
<theme>
<parent>blacknwhite/default</parent>
<layout>
<updates>
<hoi_default>
<!--should be linking to app/design/frontend/hoi/default/layout/parentslocal.xml-->
<file>hoi/parentslocal.xml</file>
</hoi_default>
<hoi_default>
<!--should be linking to app/design/frontend/hoi/default/layout/local.xml-->
<file>hoi/local.xml</file>
</hoi_default>
</updates>
</layout>
</theme>
This way I hoped to have my own local.xml for my theme which would fall back onto a parentslocal.xml which I would then copy the contents of the parents local.xml to. But it's not working.
I tested it by putting the below in my local.xml but it did not work.
<layout version="0.1.0">
<default>
<reference name="header">
<remove name="cart_sidebar"/>
</reference>
</default>
</layout>
I would have thought Magento would inherit from it's parent's theme more seamlessly.
I'm thinking it is perhaps better off putting my sub theme in blacknwhite/hoi!
Best Answer
I found the problem was with my syntax, as per Alan Storms post on infinite theme's fallaback the proper syntax is:
So in my case this meant I needed: