I know there are a lot discussion about 'Realm accessed from incorrect thread.', but my case a bit different, at least to my eyes...
So I have the following data structure
class User: Object, Mappable {
dynamic var name: String?
dynamic var photo: Photo?
}
class Photo: Object, Mappable {
dynamic var cover: CoverPhoto?
let photos = List<PhotoData>() // User uploaded photos, not cover
}
class CoverPhoto: Object, Mappable {
dynamic var id: String?
dynamic var user: String?
var photos = List<PhotoData>() // Different size of cover photo
}
class PhotoData : Object, Mappable {
let width = RealmOptional<Int>()
let height = RealmOptional<Int>()
dynamic var url : String?
}
I am using ObjectMapper with alamofire to map my realm objects received via rest response.
The use data is already managed and in realm db.
There is a functionality to change cover photo thus via rest receiving the new set of cover photo list and wanted to replace it.
For that reason I'm replacing it by first remove existing and appending new one.
The problem occurred when trying to access to new data which received via rest which supposed to not be a managed object, but getting exception mentioned in description.
The code which updating realm object is below and it called right after received response via alamofire, so no any DB actions in between
func updateCoverPhotos(userData: User, photo: Photo, onSuccess: ((Bool) -> Void)?, onError: ((NSError) -> Void)?) {
let userDataRef = ThreadSafeReference(to: userData)
let photos = photo.photos
DispatchQueue.global().async {
do {
let realm = try! Realm()
realm.refresh()
guard let user = realm.resolve(userDataRef) else {
return // user was deleted
}
try realm.write {
user.photo!.cover!.photos.removeAll()
user.photo!.cover!.photos.append(objectsIn: photos)
}
DispatchQueue.main.sync {
print(photoData) // Exception thrown 'Realm accessed from incorrect thread.'
onSuccess?(true)
}
} catch let error as NSError {
DispatchQueue.main.async {
onError?(error)
}
}
}
}
Could you please have a look and let me know what I'm doing wrong here ?
UPDATED
Mapping right after response, which contains new list of: PhotoData
return alamofireManager.request(url, method: .post,
parameters: parameters,
encoding: JSONEncoding.default,
headers: alamofireManager.buildHeaders())
.validate()
.responseObject(keyPath: "data") { (response: DataResponse<Photo>) in
Related
I know this question is asked a lot, but I can't figure out how to apply any answers to my program. Sorry in advance this async stuff makes absolutely zero sense to me.
Basically, I have a button in SwiftUI that, when pressed, calls a function that makes two API calls to Google Sheets using Alamofire and GoogleSignIn.
Button("Search") {
if fullName != "" {
print(SheetsAPI.nameSearch(name: fullName, user: vm.getUser()) ?? "Error")
}
}
This function should return the values of some cells on success or nil on an error. However, it only ever prints out "Error". Here is the function code.
static func nameSearch<S: StringProtocol>(name: S, advisory: S = "", user: GIDGoogleUser?) -> [String]? {
let name = String(name)
let advisory = String(advisory)
let writeRange = "'App Control'!A2:C2"
let readRange = "'App Control'!A4:V4"
// This function can only ever run when user is logged in, ! should be fine?
let user = user!
let parameters: [String: Any] = [
"range": writeRange,
"values": [
[
name,
nil,
advisory
]
]
]
// What I want to be returned
var data: [String]?
// Google Identity said use this wrapper so that the OAuth tokens refresh
user.authentication.do { authentication, error in
guard error == nil else { return }
guard let authentication = authentication else { return }
// Get the access token to attach it to a REST or gRPC request.
let token = authentication.accessToken
let headers: HTTPHeaders = ["Authorization": "Bearer \(token)"]
AF.request("url", method: .put, parameters: parameters, encoding: JSONEncoding.default, headers: headers).responseString { response in
switch response.result {
case .success:
// I assume there is a better way to make two API calls...
AF.request("anotherURL", headers: headers).responseDecodable(of: NameResponseModel.self) { response2 in
switch response2.result {
case .success:
guard let responseData = response2.value else { return }
data = responseData.values[0]
// print(responseData.values[0]) works fine
case .failure:
print(response2.error ?? "Unknown error.")
data = nil
}
}
case .failure:
print(response.error ?? "Unknown error.")
data = nil
}
}
}
// Always returns nil, "Unknown error." never printed
return data
}
The model struct for my second AF request:
struct NameResponseModel: Decodable { let values: [[String]] }
An example API response for the second AF request:
{
"range": "'App Control'!A4:V4",
"majorDimension": "ROWS",
"values": [
[
"Bob Jones",
"A1234",
"Cathy Jones",
"1234 N. Street St. City, State 12345"
]
]
}
I saw stuff about your own callback function as a function parameter (or something along those lines) to handle this, but I was completely lost. I also looked at Swift async/await, but I don't know how that works with callback functions. Xcode had the option to refactor user.authentication.do { authentication, error in to let authentication = try await user.authentication.do(), but it threw a missing parameter error (the closure it previously had).
EDIT: user.authentication.do also returns void--another reason the refactor didn't work (I think).
There is probably a much more elegant way to do all of this so excuse the possibly atrocious way I did it.
Here is the link to Google Identity Wrapper info.
Thanks in advance for your help.
Solved my own problem.
It appears (according to Apple's async/await intro video) that when you have an unsupported callback that you need to run asynchronously, you wrap it in something called a Continuation, which allows you to manually resume the function on the thread, whether throwing or returning.
So using that code allows you to run the Google Identity token refresh with async/await.
private static func auth(_ user: GIDGoogleUser) async throws -> GIDAuthentication? {
typealias AuthContinuation = CheckedContinuation<GIDAuthentication?, Error>
return try await withCheckedThrowingContinuation { (continuation: AuthContinuation) in
user.authentication.do { authentication, error in
if let error = error {
continuation.resume(throwing: error)
} else {
continuation.resume(returning: authentication)
}
}
}
}
static func search(user: GIDGoogleUser) async throws {
// some code
guard let authentication = try await auth(user) else { ... }
// some code
}
I then ran that before using Alamofire's built-in async/await functionality for each request (here's one).
let dataTask = AF.request(...).serializingDecodable(NameResponseModel.self)
let response = try await dataTask.value
return response.values[0]
Not familiar enough with AWS, but I have some Codable models I need to initialize from AWS. I'm getting JSON result from AWSTask.result (which is AnyObject). I'm trying to avoid creating Data from Dictionaty and back to a struct (to be able to use Codable).
I tied to use AWSNetworkingHTTPResponseInterceptor, but it was never got called and I couldn't find any example of using it.
self.getGatewayClient { (apiGatewayClient: AWSAPIGatewayClient?) in
let queryParameters = ...
let headerParameters = ...
apiGatewayClient?.invokeHTTPRequest(
"GET",
urlString: "/path",
pathParameters: [:],
queryParameters: queryParameters,
headerParameters: headerParameters,
body: nil,
responseClass: nil
).continueWith { (task: AWSTask<AnyObject>) -> Any? in
if let data = task... { // Get response as Data type??
}
if let result = task.result as? [String: Any] {
// Thanks, but I have a Codable, so I'll just take the data thank you.
}
return task
}
}
AWS's AWSAPIGatewayClient has two functions, one is: invokeHTTPRequest (which was what was used). There is another one called invoke, which returns data. It takes a AWSAPIGatewayRequest request:
func someTask(completion: #escaping (String?) -> ()) {
self.getGatewayClient { (apiGatewayClient: AWSAPIGatewayClient?) in
let request = AWSAPIGatewayRequest(httpMethod: "GET",
urlString: "/path",
queryParameters: queryParameters,
headerParameters: headerParameters,
httpBody: nil)
apiGatewayClient?.invoke(request).continueOnSuccessWith { response in
if let data = response.result?.responseData {
// Init Codable using data
}
}
}
}
Hello new to Swift and Alamofire,
The issue i'm having is when I call this fetchAllUsers() the code will return the empty users array and after it's done executing it will go inside the AF.request closure and execute the rest.
I've done some research and I was wondering is this is caused by Alamofire being an Async function.
Any suggestions?
func fetchAllUsers() -> [User] {
var users = [User]()
let allUsersUrl = baseUrl + "users/"
if let url = URL(string: allUsersUrl) {
AF.request(url).response { response in
if let data = response.data {
users = self.parse(json: data)
}
}
}
return users
}
You need to handle the asynchrony in some way. This this means passing a completion handler for the types you need. Other times it means you wrap it in other async structures, like promises or a publisher (which Alamofire also provides).
In you case, I'd suggest making your User type Decodable and allow Alamofire to do the decoding for you.
func fetchAllUsers(completionHandler: #escaping ([User]) -> Void) {
let allUsersUrl = baseUrl + "users/"
if let url = URL(string: allUsersUrl) {
AF.request(url).responseDecodable(of: [User].self) { response in
if let users = response.value {
completionHandler(users)
}
}
}
}
However, I would suggest returning the full Result from the response rather than just the [User] value, otherwise you'll miss any errors that occur.
I am building an app that will work with Plaid. Plaid provides a nice little LinkKit that I need to use to grab my link_token. I provide that link_token to authenticate to a bank. I have written a request using Alamofire to send the .post to get the new link_token when someone would want to add another account. My issue is when I decode the JSON to a struct that I have built I cant seem to use that stored link_token value.
Code to retrieve link_token
let parameters = PlaidAPIKeys(client_id: K.plaidCreds.client_id,
secret: K.plaidCreds.secret,
client_name: K.plaidCreds.client_name,
language: K.plaidCreds.language,
country_codes: [K.plaidCreds.country_codes],
user: [K.plaidCreds.client_user_id: K.plaidCreds.unique_user_id],
products: [K.plaidCreds.products])
func getLinkToken() {
let linkTokenRequest = AF.request(K.plaidCreds.plaidLinkTokenURL,
method: .post,
parameters: parameters,
encoder: JSONParameterEncoder.default).responseDecodable(of: GeneratedLinkToken.self) { response in
print(response)
}
}
Struct I have built:
struct GeneratedLinkToken: Decodable {
let expiration: String
let linkToken: String
let requestID: String
enum CodingKeys: String, CodingKey {
case expiration = "expiration"
case linkToken = "link_token"
case requestID = "request_id"
}
}
I have tested by calling the function getLinkToken() when pressing my add account or dummy button, I do get the data back that I am needing. Why wouldnt I be able to access GeneratedLinkToken.linkToken directly after the request?
You aren't able to access linkToken property like this: GeneratedLinkToken.linkToken, because linkToken is as instance property(read here)
If you want to get an instance after your request, you can do it like this:
func getLinkToken(completion: #escaping ((GeneratedLinkToken) -> Void)) {
let linkTokenRequest = AF.request(K.plaidCreds.plaidLinkTokenURL,
method: .post,
parameters: parameters,
encoder: JSONParameterEncoder.default).responseDecodable(of: GeneratedLinkToken.self) { response in
print(response)
// if response is an object of type GeneratedLinkToken
switch response.result {
case .success(let object):
completion(object)
case .failure(let error):
// hanlde error
}
}
}
Later you can call as:
getLinkToken { linkObject in
print("My tokne: \(linkObject.linkToken)")
}
I added completion(read here) to your method, since the request executing async, you can take a look at this Q/A: read here. I also suggest you, pass parameters as a parameter to this function, not declare it globally.
I have a function that calls 2 types of api requests to get a bunch of data i need in my app. In the function I make a request for locations, then for each location in the response I make a different request to get details of that specific location. (ex. if request 1 returns 20 locations, my second request is called 20 times, once for each location)
My function code here:
func requestAndCombineGData(location: CLLocation, radius: Int) {
// Clears map of markers
self.mapView.clear()
// Calls 'Nearby Search' request
googleClient.getGooglePlacesData(location: location, withinMeters: radius) { (response) in
print("Made Nearby Search request. Returned response here:", response)
// loops through each result from the above Nearby Request response
for location in response.results {
// Calls 'Place Details' request
self.googleClient.getGooglePlacesDetailsData(place_id: location.place_id) { (detailsResponse) in
print("GMV returned - detailsResponse.result - ", detailsResponse.result)
}
}
}
}
Request functions I reference above are here:
func getGooglePlacesData(location: CLLocation, withinMeters radius: Int, using completionHandler: #escaping (GooglePlacesResponse) -> ()) {
for category in categoriesArray {
let url = googlePlacesNearbyDataURL(forKey: googlePlacesKey, location: location, radius: radius, type: category)
let task = session.dataTask(with: url) { (responseData, _, error) in
if let error = error {
print(error.localizedDescription)
return
}
guard let data = responseData, let response = try? JSONDecoder().decode(GooglePlacesResponse.self, from: data) else {
print("Could not decode JSON response")
completionHandler(GooglePlacesResponse(results:[]))
return
}
if response.results.isEmpty {
print("GC - response returned empty", response)
} else {
print("GC - response contained content", response)
completionHandler(response)
}
}
task.resume()
}
}
func getGooglePlacesDetailsData(place_id: String, using completionHandler: #escaping (GooglePlacesDetailsResponse) -> ()) {
let url = googlePlacesDetailsURL(forKey: googlePlacesKey, place_ID: place_id)
let task = session.dataTask(with: url) { (responseData, _, error) in
if let error = error {
print(error.localizedDescription)
return
}
guard let data = responseData, let detailsResponse = try? JSONDecoder().decode(GooglePlacesDetailsResponse.self, from: data) else {
print("Could not decode JSON response. responseData was: ", responseData)
return
}
print("GPD response - detailsResponse.result: ", detailsResponse.result)
completionHandler(detailsResponse)
}
task.resume()
}
After I get all the data im requesting (or even as the data is coming in) I would like to append it to an #EnvironmentObject (array) I have set up in my SceneDelegate.swift file. Im using the data in multiple places in my app so the #EnvironmentObject serves as a 'source of truth'.
I tried accomplishing this using the code below, but keep getting the error - "Publishing changes from background threads is not allowed; make sure to publish values from the main thread (via operators like receive(on:)) on model updates."
func requestAndCombineGData(location: CLLocation, radius: Int) {
// Clears map of markers
self.mapView.clear()
// Calls 'Nearby Search' request
googleClient.getGooglePlacesData(location: location, withinMeters: radius) { (response) in
print("Made Nearby Search request. Returned response here:", response)
// loops through each result from the above Nearby Request response
for location in response.results {
// Calls 'Place Details' request
self.googleClient.getGooglePlacesDetailsData(place_id: location.place_id) { (detailsResponse) in
print("GMV returned - detailsResponse.result - ", detailsResponse.result)
// THIS IS WHERE I TRY TO UPDATE MY #ENVIROMETOBJECT
self.venueData.venuesdataarray.append(detailsRespose.result)
}
}
}
}
I believe I need to make sure the requests complete THEN try to update my #EnvironmentObject, but I do not know how to do that.
EDIT - providing my VenueData struct as requested in comments:
struct VenueData : Identifiable {
var id = UUID()
var name : String
var geometry : Location?
var rating : String?
var price_level : String?
var types : [String]?
var formatted_address : String?
var formatted_phone_number : String?
var website : String?
var photo_reference : String?
enum CodingKeysDetails : String, CodingKey {
case geometry = "geometry"
case name = "name"
case rating = "rating"
case price_level = "price_level"
case types = "types"
case opening_hours = "opening_hours"
case formatted_address = "formatted_address"
case formatted_phone_number = "formatted_phone_number"
case website = "website"
}
// Location struct
struct Location : Codable {
var location : LatLong
enum CodingKeys : String, CodingKey {
case location = "location"
}
// LatLong struct
struct LatLong : Codable {
var latitude : Double
var longitude : Double
enum CodingKeys : String, CodingKey {
case latitude = "lat"
case longitude = "lng"
}
}
}
}
class VenueDataArray: ObservableObject {
#Published var venuesdataarray : [VenueData] = [
VenueData(name: "test_name")
]
}
Solution Edit - I tried using this snippet of code within my second api request and it solved my issue, although i do not understand why I need to do this
DispatchQueue.main.async {
self.venueData.venuesdataarray.append(RESPONSE_DETAILS_HERE)
}
Originally I had asked, Does anyone know how I can update my #EnvironmentObject after all the requests complete?
Does anyone know why the snippet I have above makes everything work?
Id just like to understand what im doing and maybe someone could learn something if they find this
I tried using this snippet of code within my second api request and it solved my issue, although i do not understand why I need to do this
DispatchQueue.main.async {
self.venueData.venuesdataarray.append(RESPONSE_DETAILS_HERE)
}
Originally I had asked, Does anyone know how I can update my #EnvironmentObject after all the requests complete?
Does anyone know why the snippet I have above makes everything work? Id just like to understand what im doing and maybe someone could learn something if they find this
There are several things that you cannot successfully do from a background thread. Some of them (like UIKit content changes) do not generate an error, but fail silently which is worse. You have the good fortune to have received a relatively specific error message.
The error message was that you couldn't publish changes from a background thread and needed to do that from the main thread.
Wrapping your append inside "DispatchQueue.main.async" makes that line of code run on the main thread.
That's it.
This could probably have been explained more concisely.