Handling Firebase asynchronous callbacks with Combine framework.
To run the example project, clone the repo, and run pod install
from the Example directory first. See Usage below for more information.
CombineFirebase
is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'CombineFirebase/Firestore'
pod 'CombineFirebase/RemoteConfig'
pod 'CombineFirebase/Database'
pod 'CombineFirebase/Storage'
pod 'CombineFirebase/Auth'
pod 'CombineFirebase/Functions'
CombineFirebase
is available through Swift Package Manager in beta status. To install it, you must have Xcode 12.0 and above, simply add CombineFirebase
to an existing Xcode project as a package dependency:
import CombineFirebase
import Firebase
import Combine
Basic write operation
var cancelBag = Set<AnyCancellable>()
func setUserData() {
let ref = Database.database().reference()
ref.child("users")
.child("1")
.setValue(["username": "Arnonymous"])
.sink { _ in
print("Document successfully updated")
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#basic_write
Listen for value events
var cancelBag = Set<AnyCancellable>()
func listenForValueEvent() {
let ref = Database.database().reference()
ref.child("users")
.child("1")
.publisher(.value)
.receive(on: RunLoop.main)
.sink { snapshot in
print("Value:\(snapshot.value)")
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#listen_for_value_events
Read data once
var cancelBag = Set<AnyCancellable>()
func readDataOnce() {
let ref = Database.database().reference()
ref.child("users")
.child("1")
.observeSingleEvent(.value)
.receive(on: RunLoop.main)
.sink { snapshot in
print("Value:\(snapshot.value)")
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#read_data_once
Update specific fields
var cancelBag = Set<AnyCancellable>()
func updateFields() {
let ref = Database.database().reference()
let childUpdates = ["/posts/\(key)": post,
"/user-posts/\(userID)/\(key)/": post]
ref.updateChildValues(childUpdates)
.receive(on: RunLoop.main)
.sink { _ in
// Success
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#update_specific_fields
Delete data
var cancelBag = Set<AnyCancellable>()
func deleteData() {
let ref = Database.database().reference()
ref.removeValue()
.receive(on: RunLoop.main)
.sink { _ in
// Success
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#delete_data
Save data as transactions
var cancelBag = Set<AnyCancellable>()
func saveDataAsTransaction() {
let ref = Database.database().reference()
ref.runTransactionBlock { currentData in
// TransactionResult
}.sink { _ in
// Success
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/database/ios/read-and-write#save_data_as_transactions
Setting data
var cancelBag = Set<Cancellable>()
let db = Firestore.firestore()
struct City: Codable {
var name: String? = nil
var state: String? = nil
var country: String? = nil
var capital: String? = nil
var population: Int? = nil
// local variable
var id: String? = nil
}
func setSanFranciscoData(city: City) {
let onErrorCompletion: ((Subscribers.Completion<Error>) -> Void)? = { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}
let onValue: (Void) -> Void = {
print("✅ value")
}
// Add a new document in collection "cities"
(db.collection("cities")
.document("SF")
.setData(from: city) as AnyPublisher<Void, Error>) // Note: you can use (as Void) for simple setData({})
.sink(receiveCompletion: onErrorCompletion, receiveValue: onValue)
.store(in: &cancelBag)
}
// Add a new document with a generated id.
func addSanFranciscoDocument(city: City) {
(db.collection("cities")
.addDocument(data: [
"name": "San Francisco",
"state": "CA",
"country": "USA",
"capital": false,
"population": 860000
]) as AnyPublisher<DocumentReference, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}) { ref in
print("Document added with ID: \(ref.documentID)")
}
.store(in: &cancelBag)
}
// Set the "capital" field of the city 'SF'
func updateSanFranciscoDocument() {
(db.collection("cities")
.document("SF")
.updateData([
"capital": true
]) as AnyPublisher<Void, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print(i"❗️ failure: \(error)")
}) { _ in }
.store(in: &cancelBag)
}
// https://firebase.google.com/docs/firestore/manage-data/add-data
Get a document
func getDocument() {
db.collection("cities")
.document("SF")
.getDocument()
.sink(receiveCompletion: { (completion) in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { document in
print("Document data: \(document.data())")
}
.store(in: &cancelBag)
}
func getDocumentAsObject() {
db.collection("cities")
.document("SF")
.getDocument(as: City.self)
.sink(receiveCompletion: { (completion) in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { city in
print("City: \(city)")
}
.store(in: &cancelBag)
}
// https://firebase.google.com/docs/firestore/query-data/get-data
Get Realtime updates
let db = Firestore.firestore()
// Document
func listenDocument() {
db.collection("cities")
.document("SF")
.publisher()
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { document in
print("Document data: \(document.data())")
}
.store(in: &cancelBag)
}
var cityDocumentSnapshotMapper: (DocumentSnapshot) throws -> City? {
{
var city = try $0.data(as: City.self)
city.id = $0.documentID
return city
}
}
func listenDocumentAsObject() {
db.collection("cities")
.document("SF")
.publisher(as: City.self, documentSnapshotMapper: cityDocumentSnapshotMapper)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { city in
print("City: \(city)")
}
.store(in: &cancelBag)
}
// Collection
func listenCollection() {
db.collection("cities")
.publisher()
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { snapshot in
print("collection data: \(snapshot.documents)")
}.store(in: &cancelBag)
}
func listenCollectionAsObject() {
db.collection("cities")
.publisher(as: City.self, documentSnapshotMapper: cityDocumentSnapshotMapper)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { cities in
print("Cities: \(cities)")
}.store(in: &cancelBag)
}
// https://firebase.google.com/docs/firestore/query-data/listen
Batched writes
var cancelBag = Set<AnyCancellable>()
func batchWrite() {
let db = Firestore.firestore()
// Get new write batch
let batch = db.batch()
// Update the population of 'SF'
let sfRef = db.collection("cities").document("SF")
batch.updateData(["population": 1000000 ], forDocument: sfRef)
// Commit the batch
batch.commit()
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { _ in}
.store(in: &cancelBag)
}
// https://firebase.google.com/docs/firestore/manage-data/transactions
Transactions
var cancelBag = Set<AnyCancellable>()
func transaction() {
let db = Firestore.firestore()
let sfReference = db.collection("cities").document("SF")
(db.runTransaction { transaction in
let sfDocument = try transaction.getDocument(sfReference)
guard let oldPopulation = sfDocument.data()?["population"] as? Int else {
let error = NSError(
domain: "AppErrorDomain",
code: -1,
userInfo: [
NSLocalizedDescriptionKey: "Unable to retrieve population from snapshot \(sfDocument)"
]
)
throw error
}
transaction.updateData(["population": oldPopulation + 1], forDocument: sfReference)
return nil
} as AnyPublisher<Any?, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { _ in
print("Transaction successfully committed!")
}
.store(in: &cancelBag)
}
// https://firebase.google.com/docs/firestore/manage-data/transactions
Fetch
// TimeInterval is set to expirationDuration here, indicating the next fetch request will use
// data fetched from the Remote Config service, rather than cached parameter values, if cached
// parameter values are more than expirationDuration seconds old. See Best Practices in the
// README for more information.
var cancelBag = Set<AnyCancellable>()
func fetchRemoteConfig() {
(RemoteConfig.remoteConfig()
.fetch(withExpirationDuration: TimeInterval(expirationDuration), activateFetched: true) as AnyPublisher<RemoteConfigFetchStatus, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("❗️ failure: \(error)")
}
}) { status in
print("Config fetched! with success:\(status == .success)")
}
.store(in: &cancelBag)
}
// https://firebase.google.com/docs/remote-config/ios
Upload
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
let data: Data // Upload data
(reference.putData(data) as AnyPublisher<StorageMetadata, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { metadata in
// Success
}
.store(in: &cancelBag)
let fileURL: URL // Upload file
(reference.putFile(from: fileURL) as AnyPublisher<StorageMetadata, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { metadata in
// Success
}
.store(in: &cancelBag)
Observe events
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
let fileURL: URL // Upload file
let uploadTask = reference.putFile(from: fileURL)
// Listen for state changes
uploadTask.publisher(.progress)
.sink(receiveCompletion: { _ in
print("�� finished")
}) { snapshot in
if let error = snapshot.error {
print("error: \(error)")
}
// Upload reported progress
let percentComplete = 100.0 * Double(snapshot.progress?.completedUnitCount ?? 0)
/ Double(snapshot.progress.totalUnitCount ?? 1)
}
.store(in: &cancelBag)
Download
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
// Download in memory with a maximum allowed size of 1MB (1 * 1024 * 1024 bytes)
(reference.getData(maxSize: 1 * 1024 * 1024) as AnyPublisher<Data, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { data in
// Data for "images/space.jpg" is returned
}
.store(in: &cancelBag)
// Create local filesystem URL
let localURL = URL(string: "path/to/image")!
// Download to the local filesystem
(reference.write(toFile: localURL) as AnyPublisher<URL, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { data in
// Local file URL for "images/space.jpg" is returned
}
.store(in: &cancelBag)
URL
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
// Fetch the download URL
(reference.downloadURL() as AnyPublisher<URL, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { data in
// Get the download URL for 'images/space.jpg'
}
.store(in: &cancelBag)
Metadata
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
// Create file metadata to update
let newMetadata = StorageMetadata()
// Update metadata properties
(reference.updateMetadata(newMetadata) as AnyPublisher<StorageMetadata, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { metadata in
// Updated metadata for 'images/space.jpg' is returned
}
.store(in: &cancelBag)
// Get metadata properties
(reference.getMetadata() as AnyPublisher<StorageMetadata, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { metadata in
// Metadata now contains the metadata for 'images/space.jpg'
}
.store(in: &cancelBag)
Delete
var cancelBag = Set<AnyCancellable>()
let reference = Storage.storage()
.reference(forURL: "\(your_firebase_storage_bucket)/images/space.jpg")
// Delete the file
(reference.delete() as AnyPublisher<Void, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { _ in
// File deleted successfully
}
.store(in: &cancelBag)
Create
var cancelBag = Set<AnyCancellable>()
let auth = Auth.auth()
// Create a password-based account
(auth.createUser(withEmail: "xxx@xxx.com", password: "1q2w3e4r") as AnyPublisher<AuthDataResult, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { _ in
// User signed in
}.store(in: &cancelBag)
// https://firebase.google.com/docs/auth/ios/password-auth
Sign in
var cancelBag = Set<AnyCancellable>()
let auth = Auth.auth()
// Sign in a user with an email address and password
(auth.signIn(withEmail: "xxx@xxx.com", password: "1q2w3e4r") as AnyPublisher<AuthDataResult, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { _ in
// User signed in
}.store(in: &cancelBag)
// https://firebase.google.com/docs/auth/ios/password-auth
Update email
var cancelBag = Set<AnyCancellable>()
let user = Auth.auth().currentUser
// Set a user's email address
(user.updateEmail(to: "xxx@xxx.com") as AnyPublisher<Void, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { _ in
// Completed updating Email
}.store(in: &cancelBag)
// https://firebase.google.com/docs/auth/ios/manage-users
Delete
var cancelBag = Set<AnyCancellable>()
let user = Auth.auth().currentUser
// Delete a user
(user.delete() as AnyPublisher<Void, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): // Uh-oh, an error occurred!
}
}) { _ in
// User deleted
}.store(in: &cancelBag)
// https://firebase.google.com/docs/auth/ios/manage-users
var cancelBag = Set<AnyCancellable>()
let functions = Functions.functions()
let request = functions.httpsCallable("functionName")
(request
.call(["parameter": "value"]) as AnyPublisher<HTTPSCallableResult, Error>)
.sink(receiveCompletion: { completion in
switch completion {
case .finished: print("�� finished")
case .failure(let error): print("error:\(error)")
}
}) { result in
print("response:\(result)")
}.store(in: &cancelBag)
// https://firebase.google.com/docs/functions/callable#call_the_function
Kumar Shivang, shivang.iitk@gmail.com
CombineFirebase is available under the MIT license. See the LICENSE file for more info.