Firebase Firestore not working in Swift Share Extension - swift

Question

I am building a Share Extension in Swift which saves a document to Firestore. So far I have been able to authenticate the correct user via keychain sharing and app groups. I can also get a documentID from a new document reference:
var ref = Firestore.firestore().collection("stuff").document()
print(ref.documentID) //prints the id
But when I try to save something to Firestore, nothing prints in the console, meaning I get neither a failure or success callback from Firebase (see below where I batch the updates). Here is my ShareController.swift file:
class ShareViewController: SLComposeServiceViewController {
var sharedIdentifier = "asdf"
override func viewDidLoad() {
FirebaseApp.configure()
setupKeychainSharing()
}
func setupKeychainSharing() {
do {
try Auth.auth().useUserAccessGroup(sharedIdentifier)
} catch let error as NSError {
}
}
override func isContentValid() -> Bool {
return true
}
override func didSelectPost() {
if let content = extensionContext!.inputItems[0] as? NSExtensionItem {
if let contents = content.attachments {
for attachment in contents {
if attachment.hasItemConformingToTypeIdentifier(m4aType) {
attachment.loadItem(forTypeIdentifier: m4aType, options: nil, completionHandler: { (results, error) in
if error == nil {
if let url = results as? URL {
if let audioData = NSData(contentsOf: url) {
let fileName = url.lastPathComponent
if Auth.auth().currentUser != nil {
guard let myId = Auth.auth().currentUser?.uid else { return }
let batch = Firestore.firestore().batch()
let ref = Firestore.firestore().collection("projects").document()
let project: [String: Any] = [
"ownerId": myId,
"type" : "audio",
"extensionUrl" : audioUrl.absoluteString
]
batch.updateData(project, forDocument: ref)
let privateRef = Firestore.firestore().collection("user-private").document(myId)
let privateUpdate: [String: Any] = [
"projects" : FieldValue.arrayUnion([ref.documentID])
]
batch.updateData(privateUpdate, forDocument: privateRef)
batch.commit(completion: { (error) in
if let error = error {
print("error updating database: \(error.localizedDescription)")
} else {
print("Database updated successfully!!!!!")
self.extensionContext!.completeRequest( returningItems: [], completionHandler: nil)
}
})
}
}
}
}
})
}
}
}
}
}
}

Answer 1

It appears you're trying to create additional documents within the projects node and update the user-private node. If so, the code in the question won't work.
UpdateData: Updates fields in the document referred to by document. If
document does not exist, the write batch will fail.
Here's a working batch write function that adds a document to a projects node with a Firestore generated document ID and child fields for extension, ownerId and type as well as a user_private collection with a document with a documentId of id_0.
func batchWrite() {
let batch = self.db.batch()
let ref = self.db.collection("projects").document()
let project: [String: Any] = [
"ownerId": "id_0",
"type" : "audio",
"extensionUrl" : "some url"
]
batch.setData(project, forDocument: ref)
let privateRef = self.db.collection("user-private").document("id_0")
let privateUpdate: [String: Any] = [
"projects" : "some projects"
]
batch.setData(privateUpdate, forDocument: privateRef)
batch.commit(completion: { (error) in
if let error = error {
print("error updating database: \(error.localizedDescription)")
} else {
print("Database updated successfully!!!!!")
}
})
}
Note that self.db is a class var reference to my Firestore. That makes it so you don't have to keep typing Firestore.firestore() and use self.db instead.
Also note that a batch is probably not needed in this case as it doesn't appear there are a significant number of writes occurring at the same time.
If you're not using batch, the .addDocument will add documents to collections.
Here's a function that writes a task to a tasks collection and auto-generates a documentId
func writeTask() {
let collectionRef = self.db.collection("tasks")
let data = [
"task": "some task"]
var ref: DocumentReference? = nil
ref = collectionRef.addDocument(data: data, completion: { err in
if let error = err {
print(error.localizedDescription)
}
print(ref?.documentID)
})
}

Answer 2

It is likely Firebase wasn't configured for your Share extension. Print statements do not work for share extension. Instead you should make use of NSLog statements i.e NSLog("refDocId:\(ref.DocumentId)"). Then in your xcode, navigate to Window > Devices and Simulators > Open Console. To configure Firebase in your Share extension, use FirebaseApp.configure()