I would like to create a custom fetch descriptor using the techniques described in this article. Specifically, I would like to limit properties retrieved using .propertiesToFetch.

The project I am working on uses techniques described in this article to create a dynamic filter predicate. That is working well. What I can't figure out is how to marry the two.

The following is the init in my view that leverages the filtered data. How do I incorporate the concept of the custom fetch descriptor so that I only fetch certain properties?

It's not clear if/how I can do that with the _items = Query(filter: predicate, sort: sortDescriptors) construct.

While I'm here ;-), in my everquest to learn, if there other ways to improve they way I'm handling the predicate please share!

I would appreciate any guidance. thanks -- jay

init(filterText: String, filter: Filter, settingsVM: SettingsViewModel) {

      self.filter = filter

      self.settingsVM = settingsVM
      _journalViewType = State(initialValue: settingsVM.defaultJournalView)

      // use computed variables for Predicate to work
      let distantPast = Date.distantPast
      let last7DaysFilter = filter.id == .last7
      let last30DaysFilter = filter.id == .last30
      let lastYearFilter = filter.id == .lastYear
      let last7Days = Calendar.current.date(byAdding: .day, value: -7, to: Date.now)!
      let last30Days = Calendar.current.date(byAdding: .month, value: -1, to: Date.now)!
      let lastYear = Calendar.current.date(byAdding: .year, value: -1, to: Date.now)!

      let sortDescriptors: [SortDescriptor<Item>] = [SortDescriptor(\Item.date, order: .reverse)]

      // compound expression to check for date filter AND search text if it exists

      let predicate = #Predicate<Item> { item in
         if last7DaysFilter {
            return item.date > last7Days && (item.text.localizedStandardContains(filterText) || (item.locationForFilterPredicate.localizedStandardContains(filterText)) || filterText.isEmpty)
         } else if last30DaysFilter {
            return item.date > last30Days && (item.text.localizedStandardContains(filterText) || (item.locationForFilterPredicate.localizedStandardContains(filterText)) || filterText.isEmpty)
         } else if lastYearFilter {
            return item.date > lastYear && (item.text.localizedStandardContains(filterText) || (item.locationForFilterPredicate.localizedStandardContains(filterText)) || filterText.isEmpty)
         } else {
            return item.date > distantPast && (item.text.localizedStandardContains(filterText) || (item.locationForFilterPredicate.localizedStandardContains(filterText)) || filterText.isEmpty)
         }
      }
      _items = Query(filter: predicate, sort: sortDescriptors)
   }