I thought this might be have been asked before but couldn't find anything. Perhaps it's really obvious and I'm just stupid...

My model has a mix of fields that won't change and fields that might change (server-side) and I want it to stay up to date. Ideally I'd request the full JSON when the application is started, then periodically update it with a JSON which only has values for a subset of fields.

I can't work out how to do this without splitting it into 2 models and combining them in the view, which seems like a lot more work. Am I missing something?

Many thanks for any help!