I wanna know how to retrieve the r… | Apple Developer Forums

I wanna know how to retrieve the records from the public database on Apple CloudKit in synchronous processing.

I'm trying to retrieve record from the public database of CloudKit. (Swift version 5.6 , Xcode 13.3 and iOS 15.4)

From Content.view, I call the function vm.retrieve_T100 of ViewModel.swift. The argument of it is mail address user will input. I've set the print for debug.

I want to progress like *1,*2,*3,*3,*3,*4,*5. But Actually It progressed like *1,*2,*5,3,,3,*3,*4. How should I change the program?

probably I should stop the way of asynchronous processing, and I should re-write the program in synchronous processing. I don't know how to it.

ContentView.swift

struct ContentView: View {

@EnvironmentObject var vm: ViewModel
    .....    
    var body: some View {
    .....
    func mail_choufuku_error_check(_:String) -> Bool {

        **print("*1 before retrieve_T100 *")**
        vm.retrieve_T100(in_mail_address: usr.T100_MAIL_ADDRESS)
        **print("*5 after retrieve_T100 *")**

.....

ViewModel.swift

import CloudKit

final class ViewModel: ObservableObject {
    private lazy var container = CKContainer(identifier: Config.containerIdentifier)
    private lazy var database = container.publicCloudDatabase
    .....
    
    func retrieve_T100(in_mail_address:String) {
            
        **print("*2 retrieve_T100:start !!")**

        let predicate = NSPredicate(format: "MAIL_ADDRESS == %@", in_mail_address)
        let query = CKQuery(recordType: "T100_T_SCHOOL", predicate: predicate)
        let queryOperation = CKQueryOperation(query: query)

        queryOperation.recordMatchedBlock = { record, result in
            switch result {
                case .success(let record):
                    **print("*3 retrieve_T100:(A)MAIL_ADDRESS = \**(record["MAIL_ADDRESS"]!)")
                case .failure(let error):
                    print("*3 retrieve_T100:error = \(error.localizedDescription)")
            }
        }

        queryOperation.queryResultBlock = { result in
            switch result {
                case .failure(let error):
                    print("*4 retrieve_T100:(B) Error ...")
                    print(error.localizedDescription)
                case .success:
                    **print("*4 retrieve_T100:(B) Success ...")**
            }
        }
        database.add(queryOperation)
    }
....

report of display after processing

*1 before retrieve_T100 *

*2 retrieve_T100:start !!

*5 after retrieve_T100 *

*3 retrieve_T100:(A)MAIL_ADDRESS = xxxxxxxx

*4 retrieve_T100:(B) Success ...