I don't think this is correct since you're not saving the modifications... They'll be in the cache when but they go out of the cache you'll have lost your changes.

See http://code.xwiki.org/xwiki/bin/view/Snippets/SettingRightsSnippet

-Vincent

Thanks Vincent. I thought I need to save, but then when I do, I get - Exception while saving document Patterns.ObjectsToTalkWith Wrapped Exception: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): xpn.xwiki.objects.String Property#<?xml version="1.0" encoding="UTF-8"?> <dead-field></dead-field& See: http://patternlanguagenetwork.myxwiki.org/xwiki/bin/view/scripts/fixrights