Automatically load init.m without sharing CellContext

Question

I'm trying to set up Mathematica such that all functions/variables defined in my init.m are automatically loaded into any new notebook I open. This works as a default, but I would also ideally like to set my CellContext to Notebook, such that notebook-specific functions/variables are not shared. However, doing this also makes init.m functions not work across new notebooks. I've tried figuring out how to do this with packages, but I haven't been able to find a clear resource on how I would set this up for my purposes.

To be succinct, what is the best way to set up a central file like init.m that is automatically loaded with each new notebook, but such that notebooks have their own context? Thanks for any advice/guidance you can give.

Answer 1

Using Create new notebook at fixed size you can do:

SetOptions[$FrontEnd, NotebookEventActions :> {
   {"MenuCommand", "New"} :> (
     CreateDocument[{}
     , CellContext -> Notebook
     , NotebookDynamicExpression :> Refresh[
         Get @ "init.m"
       ; SetOptions[EvaluationNotebook[], NotebookDynamicExpression :> Null]
       , None
       ]
     ]
   )
}]

But do not define your functions in init.m, put there only Needs @ "MyPackage`" and create a proper packages. That way you don't need to read a long file each time you open a notebook but all will be done by fetching a "MyPackage`" from $Packages to a local to your notebook $ContextPath.