Is there a way to dynamically switch between FetchRequest and SectionedFetchRequest? - core-data

Question

I've been playing around with CoreData in the last couple days, trying to build an app to review money spent on shopping. Right now its still pretty simple with just a single Data Model for the individual shops.
I have a list view displaying all of them and I've integrated sorting into the list, first through older workarounds around the predicates, but than I found this video from this years wwdc and I basically just copied. I've really been fascinated by the grouping feature from the SectionedFetchRequest and I wanted to integrate it, while maintaining the original non sectioned List. So I thought I'd skip the FetchRequest in my List and just pass the results to the list view instead of the SortDescriptor
MainView{
ListView(descriptor: SortDescriptor)
}
ListView{
FetchRequest(sortDescriptors: descriptor)
}
changed to:
MainView{
ListView(FetchRequest(sortDescriptors: descriptor))
}
ListView{
FetchedResults
}
But that still leaves me unable to just push a button to turn sectioning on or off.
I'm kind of stuck on how to go on from here.. First idea coming to my mind is creating a wrapper around the ListView handeling which FetchRequest to send out to the ListView based on Button toggle state like
MainView{
Wrapper(sortDescriptors, toggleState)
}
Wrapper{
ListView(FetchRequest(sortDescriptors: descriptor))
}
ListView{
FetchedResults
}
but I still would have the problem that I'd need 2 Variables in my ListView, one for the normal, and one for the sectionedFetchResults.
Has anyone an idea how to handle this ?
TLDR I want to dynamically switch between FetchRequest and SectionedFetchRequest

Answer 1

According to the documentation you can't not section a SectionedFetchRequest, therefore you would have to support both. Therefore, I would make two separate sub views, and show them in a parent view that has logic to control which one is shown. You would need to do this anyway if you are supporting pre-iOS 15 OS's.
MainView{
if sectioned
ListViewSectioned(sortDescriptors: descriptor, sectionID: sectionID)
} else {
ListView(sortDescriptors: descriptor)
}
}
ListView{
FetchRequest(sortDescriptors: descriptor)
}
ListViewSectioned{
SectionedFetchRequest(sectionIdentifier: sectionID, sortDescriptors: descriptor)
}
The main view doesn't have to know any more to choose and set up the different list views. I didn't put an OS check in, but you will need that as well.