CODEWITHSUNDEEP
swiftfirebasegoogle-cloud-firestoreswiftuifoundation
AMchou
AMchou

Reputation: 11

How to update collection in Firebase using SwiftUI?

I'm working on a patient/inventory management software on SwiftUI and I decided to ditch CoreData to go with Firebase. It seems to be less of a hassle but it's still a learning curve for me as a beginner. A dev helped me out initially to create and get the patients on the API patient file, but now that I am trying to update the data, I can't seem to figure out what to write...

I went through multiple tutorials and they all seem to be using the db.collection way of doing things.

Here is my code

import Foundation
import FirebaseFirestore
class PatientAPI {
    
    func createPatient(firstName: String, lastName: String, address: String, postCode: String, phoneNumber: String, onSuccess: @escaping(_ successMessage: String) -> Void) {
     
        let testPatient = PatientModel.init(firstName: firstName, lastName: lastName, address: address, postalCode: postCode, phoneNumber: phoneNumber)
       
        
        
        guard let dict = try? testPatient.toDictionary() else {return} /
       
        API.FIRESTORE_COLLECTION_PATIENTS.addDocument(data: dict)
        onSuccess("Done")
    }
    

    
    func getPatients(onSuccess: @escaping(_ patients: [PatientModel]) -> Void, onError: @escaping(_ errorMesage: String) -> Void) {
        
       
        API.FIRESTORE_COLLECTION_PATIENTS.getDocuments { (snapshot, error) in
            if let error = error {
                onError(error.localizedDescription)
                return
            }
            
            
            guard let snap = snapshot else {return}
            
            var patients = [PatientModel]()
            
            
           
            for document in snap.documents {
                let dict = document.data()
                guard let decodedPatient = try? PatientModel.init(fromDictionary: dict) else {return}
                patients.append(decodedPatient) 
                
            }
            onSuccess(patients) 
        }
    }
 
   
}

Thank you very much

Upvotes: 0

Views: 265

Answers (1)

Peter Friese
Peter Friese

Reputation: 7254

I'd recommend using Firebase's Codable support, as this will make your code much more readable and maintainable.

For this, your Patient should be a struct that conforms to Codable, like so:

struct Patient: Identifiable, Codable {
  @DocumentID var id: String?
  var firstName: String
  var lastName: String
  var address: String
  // ...
}

Then, to fetch all patients from a collection (or those meeting certain criteria), use Firestore's snapshot listener:

func fetchData() {
  db.collection("patients").addSnapshotListener { (querySnapshot, error) in
    guard let documents = querySnapshot?.documents else {
      print("No documents")
      return
    }
      
    self.books = documents.compactMap { queryDocumentSnapshot -> Patient? in
      return try? queryDocumentSnapshot.data(as: Patient.self)
    }
  }
}

To add new patients, first create a new patient:

let patient = Patient(firstName: "Jane", lastName: "Appleseed", /* other attributes go here */)

And then add it to the collection like this:

func addPatient(patient: Patient) {
  do {
    let _ = try db.collection("patients").addDocument(from: patient)
  }
  catch {
    print(error)
  }
}

More details about this in my article here.

Upvotes: 5

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