Hello,

As far as I know you can't use any type of editor variables inside CSS rules, neither custom nor built-in ones. Can you give us more detains about how is the user changing between different branches? Maybe we can give some alternatives, like:
- you can have different CSSs associated in the document type and the user can switch between them using the "Styles" button on the toolbar (when the branch changes)
- you can use custom pseudo-classes [1]. Firstly, you must have rules in the CSS to match the pseudo classes, maybe like this:

rootElement:-ext-branch1-pseudo-class image {
  content: url(..path1..)
}

rootElement:-ext-branch2-pseudo-class image {
  content: url(..path2..)
}

When the branch changes you must set the respective pseudo class. You can do that dynamically from the JAVA API [1] or by using an action with TogglePseudoClassOperation [2] or SetPseudoClassOperation [3].

[1] http://www.oxygenxml.com/doc/ug-oxygen/#topics/dg-custom-css-pseudo-classes.html
[2] http://www.oxygenxml.com/InstData/Editor/SDK/javadoc/ro/sync/ecss/extensions/commons/operations/TogglePseudoClassOperation.html
[3] http://www.oxygenxml.com/InstData/Editor/SDK/javadoc/ro/sync/ecss/extensions/commons/operations/SetPseudoClassOperation.html

Best regards,
Alex
-- 
Alex Jitianu
<oXygen/>  XML Editor, Schema Editor and XSLT Editor/Debugger
http://www.oxygenxml.com 

On 07-May-14 1:50 AM, Nathan wrote: