How to populate loaded records from firebase?

user_22996 0
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I wrote the function to lad the records from firebase but there's an error

Escaping closure captures mutating 'self' parameter

The function is written as follows:

let db = Firestore.firestore()
@State var libraryImages: [LibraryImage] = []

mutating func loadImages() {
        libraryImages = []
        
        db.collection(K.FStore.CollectionImages.collectionName).getDocuments() { (querySnapshot, err) in
            if let err = err {
                print("Error getting documents: \(err)")
            } else {
                if let snapshotDocuments = querySnapshot?.documents {
                    for document in snapshotDocuments {
                        let documentData = document.data()
                        let title: String = documentData[K.FStore.CollectionImages.title] as! String
                        let thumbnailUrl: String = documentData[K.FStore.CollectionImages.thumbnailUrl] as! String
                        let svgUrl: String = documentData[K.FStore.CollectionImages.svgUrl] as! String
                        let libraryImageItem = LibraryImage(title: title, thumbnailUrl: thumbnailUrl, svgUrl: svgUrl)
                        self.libraryImages.append(libraryImageItem)
                    }
                }
            }
        }
    }

Does anyone know what is causing an error and how to get rid of it?

google-cloud-firestore swiftui firebase swift
1 Answers

Move all this into reference type view model and use it as observed object in your view

Here is a demo of possible approach:

struct DemoView: View {
  @ObservedObject var vm = ImagesViewModel()
//  @StateObject var vm = ImagesViewModel()       // << SwiftUI 2.0

  var body: some View {
     Text("Loaded images: \(vm.libraryImages.count)")
       .onAppear {
           self.vm.loadImages()
       }
  }
}


class ImagesViewModel: ObservableObject {
    let db = Firestore.firestore()
    @Published var libraryImages: [LibraryImage] = []

    func loadImages() {
        libraryImages = []

        db.collection(K.FStore.CollectionImages.collectionName).getDocuments() { (querySnapshot, err) in
            if let err = err {
                print("Error getting documents: \(err)")
            } else {
                if let snapshotDocuments = querySnapshot?.documents {
                    var images = [LibraryImage]()
                    for document in snapshotDocuments {
                        let documentData = document.data()
                        let title: String = documentData[K.FStore.CollectionImages.title] as! String
                        let thumbnailUrl: String = documentData[K.FStore.CollectionImages.thumbnailUrl] as! String
                        let svgUrl: String = documentData[K.FStore.CollectionImages.svgUrl] as! String
                        let libraryImageItem = LibraryImage(title: title, thumbnailUrl: thumbnailUrl, svgUrl: svgUrl)
                        images.append(libraryImageItem)
                    }

                    DispatchQueue.main.async {
                        self.libraryImages = images
                    }
                }
            }
        }
    }
}
user_122990300
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