I'm a newbie working on some phpBB3 forum code that uses the _rootref function or array. I'm not sure what it is or what it does. My google foo attempts have turned up empty.
I'd like to know the file where it is defined and any documentation pertaining to its definition and use. Thanks.
The member variable $_rootref was introduced as part of some optimisation work, and seems to be a reference to the top-level template variables to "reduce the number of hash lookups needed."
Although it's present in the current stable release (3.0.12), it looks like it is being removed as part of the 3.1 branch. This is still under active development, as is the documentation for migrating from 3.0.