SOLVED: Day 53: Bookworm - Use of undeclared type 'Student' error when using Core Data – 100 Days of SwiftUI – Hacking with Swift forums

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SOLVED: Day 53: Bookworm - Use of undeclared type 'Student' error when using Core Data

Forums > 100 Days of SwiftUI

	@ZoydWheeler May '20 I'm having an issue with adding this code to ContentView as described in the lesson: `@FetchRequest(entity: Student.entity(), sortDescriptors: []) var students: FetchedResults<Student>` It is giving the error "Use of undeclared type Student" After searching the internet some, I found a post that suggested: right-clicking the Bookworm.xcdatamodeld file select 'Show in Finder' drag the .xcdatamodel file into your project (Note: the lack of the letter 'd' on the end of the file extension) delete the old xcdatamodeld file from your project This appears to have work, as the error went away. But why did this work? Why couldn't Xcode recognize the Student entity that I created in my xcdatamodeld file? Has anybody else experienced this? I'd like to understand better what happened. 3
	@byaruhaf May '20 i have had this issue before its due to Xcode not being able to find the automatically generated class. in your case Student Class is automatically generated & Xcode can detect that. The solutions i use is: Clean Build Folder : ⇧ + ⌘ + K closed the Xcode and reopen it Build project : ⌘ + B 12
	@ZoydWheeler May '20 Thanks for the response! I spent half the day yesterday googling/trying different methods until the one that you suggested finally did the trick. 3
	@BasTheDeveloper Jun '20 Thanks byaruhaf, that tricked solved it for me too! 3
	@prazz21 Jun '20 This did not work for me.. im still getting the same errors 3
	@bymartin Jul '20 Thanks! Worked for me. 3
	@smithi01 Jul '20 For me, this fixed the issue but created another: ! Cannot preview in this file -- Bookworm.app may have crashed. Check... 3
	@kensmash Aug '20 Unfortunately, I am experiencing the same problem as @smithi01, after following the steps suggested by @byaruhaf. I've been able to narrow the problem down somewhat - XCode compiles and runs the code just fine until i add the list code: `List { ForEach(students, id: \.id) { student in Text(student.name ?? "Unknown") } }` I've tried copying and pasting the code, typing out the code, closing and re-opening XCode, restarting the computer - nothing works. XCode only displays the "Cannot preview this file - Bookworm.app may have crashed" error message. XCode 11.6, Mac OS Catalina 10.15.5. UPDATE for anyone else having this problem. I was previewing the app in XCode's canvas. Can't remember where i came across this, but I saw somewhere that the canvas preview and Core Data don't always get along - something to do with errors when attempting to load the data. At any rate, I switched to using the simulator (as Paul was showing in his video) and it worked. 3
	@BrucknerdeV Aug '20 Thank you byaruhaf - it works! 3

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