I am now analyzing swift source code.
In this source code, performQuery is defined as function, but in line 2, performQuery is used without bracket"()". What does it mean?
Can we use a function without bracket?
I have read all the swift grammar but I cannot find similar code.
Is it related to "Unstructured Concurrency"?
==================================================
func calculateDailyQuantitySamplesForPastWeek() {
performQuery {
DispatchQueue.main.async { [weak self] in
self?.reloadData()
}
}
}
// MARK: - HealthQueryDataSource
func performQuery(completion: #escaping () -> Void) {
let predicate = createLastWeekPredicate()
let anchorDate = createAnchorDate()
let dailyInterval = DateComponents(day: 1)
let statisticsOptions = getStatisticsOptions(for: dataTypeIdentifier)
let query = HKStatisticsCollectionQuery(quantityType: quantityType,
quantitySamplePredicate: predicate,
options: statisticsOptions,
anchorDate: anchorDate,
intervalComponents: dailyInterval)
// The handler block for the HKStatisticsCollection object.
let updateInterfaceWithStatistics: (HKStatisticsCollection) -> Void = { statisticsCollection in
self.dataValues = []
let now = Date()
let startDate = getLastWeekStartDate()
let endDate = now
statisticsCollection.enumerateStatistics(from: startDate, to: endDate) { [weak self] (statistics, stop) in
var dataValue = HealthDataTypeValue(startDate: statistics.startDate,
endDate: statistics.endDate,
value: 0)
if let quantity = getStatisticsQuantity(for: statistics, with: statisticsOptions),
let identifier = self?.dataTypeIdentifier,
let unit = preferredUnit(for: identifier) {
dataValue.value = quantity.doubleValue(for: unit)
}
self?.dataValues.append(dataValue)
}
completion()
}
query.initialResultsHandler = { query, statisticsCollection, error in
if let statisticsCollection = statisticsCollection {
updateInterfaceWithStatistics(statisticsCollection)
}
}
query.statisticsUpdateHandler = { [weak self] query, statistics, statisticsCollection, error in
// Ensure we only update the interface if the visible data type is updated
if let statisticsCollection = statisticsCollection, query.objectType?.identifier == self?.dataTypeIdentifier {
updateInterfaceWithStatistics(statisticsCollection)
}
}
self.healthStore.execute(query)
self.query = query
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if let query = query {
self.healthStore.stop(query)
}
}
}
you need to learn closure. please check the link
Related
Whenever paging in tableview, the view model is running fetchDataRx. It works well, but I don't think it's right to sort the entire data every time you paginate and call the addSnapShotListener. If my code is not correct, how can I correct it?
// MARK: ViewController.swift
timeLineTableView.rx.didScroll
.withLatestFrom(viewModel.activated)
.subscribe(onNext: { [weak self] isActivated in
if !isActivated {
guard let self = self else { return }
let position = self.timeLineTableView.contentOffset.y
if position > self.timeLineTableView.contentSize.height - 100 - self.timeLineTableView.frame.size.height {
self.viewModel.fetchPosts.onNext(())
}
}
})
.disposed(by: disposeBag)
//MARK: ViewModel.swift
let fetchPosts: AnyObserver<Void>
let fetching = PublishSubject<Void>()
fetchPosts = fetching.asObserver()
fetching
.do(onNext: { _ in activating.onNext(true) })
.withLatestFrom(posts)
.map { $0.count }
.flatMap{ (count) -> Observable<[post]> in
fireBaseService.fetchDataRx(startIdx: count) }
.map { $0.map { ViewPost(post: $0) } }
.do(onNext: { _ in activating.onNext(false) })
.do(onError: { err in error.onNext(err) })
.subscribe(onNext: { newPosts in
let oldData = posts.value
posts.accept(oldData + newPosts)
})
.disposed(by: disposeBag)
//MARK: FirebaseService.swift
protocol FirebaseServiceProtocol {
func fetchDataRx(startIdx: Int) -> Observable<[post]>
func fetchData(startIdx: Int, completion: #escaping (Result<[post], Error>) -> Void)
}
class FireBaseService: FirebaseServiceProtocol {
func fetchDataRx(startIdx: Int) -> Observable<[post]> {
return Observable.create { (observer) -> Disposable in
self.fetchData(startIdx: startIdx) { result in
switch result {
case .success(let data):
observer.onNext(data)
case .failure(let error):
observer.onError(error)
}
observer.onCompleted()
}
return Disposables.create()
}
}
func fetchData(startIdx: Int, completion: #escaping (Result<[post], Error>) -> Void) {
let db = Firestore.firestore()
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm"
if startIdx == 0 {
DispatchQueue.global().async {
let first = db.collection("lolCourt")
.order(by: "date")
.limit(to: 8)
var nextPosts = [post]()
first.getDocuments() { (querySnapshot, error) in
if let error = error {
print("Error getting documents: \(error)")
} else {
for document in querySnapshot!.documents {
guard let url = document.data()["url"] as? String else {
continue
}
guard let champion1 = document.data()["champion1"] as? String else {
continue
}
guard let champion1Votes = document.data()["champion1Votes"] as? Double else {
continue
}
guard let champion2 = document.data()["champion2"] as? String else {
continue
}
guard let champion2Votes = document.data()["champion2Votes"] as? Double else {
continue
}
guard let text = document.data()["text"] as? String else {
continue
}
guard let date = document.data()["date"] as? Double else {
continue
}
nextPosts.append(post(url: url,
champion1: champion1,
champion1Votes: champion1Votes,
champion2: champion2,
champion2Votes: champion2Votes,
text: text,
date: formatter.string(from: Date(timeIntervalSince1970: date))))
}
}
completion(.success(nextPosts))
}
}
}
else {
DispatchQueue.global().async {
let first = db.collection("lolCourt")
.order(by: "date")
.limit(to: startIdx)
first.addSnapshotListener { (snapshot, error) in
guard let snapshot = snapshot else {
print("Error retrieving : \(error.debugDescription)")
return
}
guard let lastSnapshot = snapshot.documents.last else {
return
}
let next = db.collection("lolCourt")
.order(by: "date")
.start(afterDocument: lastSnapshot)
.limit(to: 8)
var nextPosts = [post]()
next.getDocuments() { (querySnapshot, error) in
if let error = error {
print("Error getting documents: \(error)")
} else {
for document in querySnapshot!.documents {
guard let url = document.data()["url"] as? String else {
continue
}
guard let champion1 = document.data()["champion1"] as? String else {
continue
}
guard let champion1Votes = document.data()["champion1Votes"] as? Double else {
continue
}
guard let champion2 = document.data()["champion2"] as? String else {
continue
}
guard let champion2Votes = document.data()["champion2Votes"] as? Double else {
continue
}
guard let text = document.data()["text"] as? String else {
continue
}
guard let date = document.data()["date"] as? Double else {
continue
}
nextPosts.append(post(url: url,
champion1: champion1,
champion1Votes: champion1Votes,
champion2: champion2,
champion2Votes: champion2Votes,
text: text,
date: formatter.string(from: Date(timeIntervalSince1970: date))))
}
}
completion(.success(nextPosts))
}
}
}
}
}
}
I think you are doing it wrong... I would expect to see something more like this:
class FireBaseService {
func getPage<T>(query: Query? = nil, build: #escaping ([String: Any]) -> T) -> Observable<([T], nextPage: Query?)> {
Observable.create { observer in
let db = Firestore.firestore()
let page = query ?? db.collection("lolCourt")
.order(by: "date")
.limit(to: 8)
let listener = page
.addSnapshotListener { snapshot, error in
guard let snapshot = snapshot else { observer.onError(error ?? RxError.unknown); return }
let items = snapshot.documents.map { build($0.data()) }
if let lastSnapshot = snapshot.documents.last {
let next = page
.start(afterDocument: lastSnapshot)
observer.onSuccess((items, nextPage: next))
}
else {
observer.onSuccess((items, nextPage: nil))
}
}
return Disposables.create { listener.remove() }
}
}
}
Use the above in your favorite state machine system. Here is an example using my CLE library.
// in view controller
let fireBaseService = FireBaseService()
let activityIndicator = ActivityIndicator()
let errorRouter = ErrorRouter()
func getPage(nextPage: Query?) -> Observable<([Post?], nextPage: Query?)> {
fireBaseService.getPage(query: nextPage, build: Post.init(dict:))
.rerouteError(errorRouter)
.trackActivity(activityIndicator)
}
let posts = cycle(
inputs: [
getPage(nextPage: nil).map(ViewModel.Input.response),
timeLineTableView.rx.reachedBottom(offset: 20).map(to: ViewModel.Input.next)
],
initialState: ([Post?](), nextPage: Query?.none),
environment: getPage(nextPage:),
reduce: ViewModel.reduce(state:input:getPage:)
)
.map { $0.0.compactMap { $0 } }
and the view model:
enum ViewModel {
enum Input {
case response([Post?], nextPage: Query?)
case next
}
static func reduce(state: inout ([Post?], nextPage: Query?), input: Input, getPage: #escaping (Query) -> Observable<([Post?], nextPage: Query?)>) -> Observable<Input> {
switch input {
case let .response(posts, nextPage):
state.0 += posts
state.nextPage = nextPage
case .next:
guard let nextPage = state.nextPage else { break }
return getPage(nextPage)
.map(Input.response)
}
return .empty()
}
}
I have a CKRecord of recipes that gets fetched to an iOS app. Once I have that list, I need to prioritize the results of recipes that are the highest suggested "likedIds" which is a list of integers representing recipe_ids (please see my dataset image below), then display the remaining recipes below that. I can't merely sort by highest rated recipes because I'm using collaborative filtering elsewhere in the project to suggest specific recipes over others, but I still want to list them all.
Here in this code below I am appending the results of NSPredicates to a list of CKQuery called 'queries'. Now that I have that [CKquery], what do I do with it? How do I fetch the results I need? Which method do I use, if publicDB.perform() isn't the right method (since I get an 'expected argument type' error)? Below, I tried using a for loop inside of the AttachToMainThread() function that I wrote, but I get 3 different random results at refresh, recipes in the "likedIds" list, recipes not the "likedIds" list, or nothing at all, yet no SIGABRT errors which is nice.
TL;DR
What do I do with my CKquery list to fetch results?
Thank you for your time!
Just the code focusing on the primary subject:
import Foundation
import CloudKit
class Model {
// MARK: - iCloud Info
let container: CKContainer
let publicDB: CKDatabase
private(set) var recipes: [Recipe] = []
static var currentModel = Model()
init() {
container = CKContainer.default()
publicDB = container.publicCloudDatabase
privateDB = container.privateCloudDatabase
}
#objc func refresh(_ completion: #escaping (Error?) -> Void) {
var queries = [CKQuery] ()
// Function that returns a CKQuery
let likedQuery = GetRecipesWithLikedIds()
queries.append(likedQuery)
// Function that returns a CKQuery
let unlikedQuery = GetRecipesWithoutLikedIds()
queries.append(unlikedQuery)
AttachToMainThread(forQuery: queries, completion)
}
private func AttachToMainThread(forQuery queries: [CKQuery],
_ completion: #escaping (Error?) -> Void) {
for q in queries {
publicDB.perform(q,
inZoneWith: CKRecordZone.default().zoneID) { [weak self] results, error in
guard let self = self else { return }
if let error = error {
DispatchQueue.main.async {
completion(error)
}
return
}
guard let results = results else { return }
self.recipes = results.compactMap {
Recipe(record: $0, database: self.publicDB)
}
DispatchQueue.main.async {
completion(nil)
}
}
}
}
}
My entire code:
import Foundation
import CloudKit
class Model {
// MARK: - iCloud Info
let container: CKContainer
let publicDB: CKDatabase
var carbohydrate = "rice"
var vegetable = "tomatoes"
// MARK: - Properties
private(set) var recipes: [Recipe] = []
static var currentModel = Model()
init() {
container = CKContainer.default()
publicDB = container.publicCloudDatabase
privateDB = container.privateCloudDatabase
}
#objc func refresh(_ completion: #escaping (Error?) -> Void) {
var queries = [CKQuery] ()
let likedQuery = GetRecipesWithLikedIds()
queries.append(likedQuery)
let unlikedQuery = GetRecipesWithoutLikedIds()
queries.append(unlikedQuery)
AttachToMainThread(forQuery: queries, completion)
}
private func AttachToMainThread(forQuery queries: [CKQuery],
_ completion: #escaping (Error?) -> Void) {
for q in queries {
publicDB.perform(q,
inZoneWith: CKRecordZone.default().zoneID) { [weak self] results, error in
guard let self = self else { return }
if let error = error {
DispatchQueue.main.async {
completion(error)
}
return
}
guard let results = results else { return }
self.recipes = results.compactMap {
Recipe(record: $0, database: self.publicDB)
}
for r in self.recipes {
self.PrettyPrintRecipes(rName: r.name, rId: String(r.recipe_id), rIng: r.ingredients)
}
DispatchQueue.main.async {
completion(nil)
}
}
}
}
func GetRecipesWithLikedIds() -> CKQuery {
let searchTextA: [String] = [carbohydrate," "+carbohydrate,carbohydrate+"s",carbohydrate+"es"]
let subPred1 = NSPredicate (format: "ANY ingredients IN %#",argumentArray: [searchTextA])
let searchTextB: [String] = [vegetable," "+vegetable,vegetable+"s",vegetable+"es"]
let subPred2 = NSPredicate (format: "ANY ingredients IN %#",argumentArray: [searchTextB])
let likedIds: [Int] = [13733,32441]
let subPred3 = NSPredicate (format: "NOT (recipe_id IN %#)", likedIds)
let and_pred1 = NSCompoundPredicate(andPredicateWithSubpredicates: [subPred1, subPred2])
let and_pred2 = NSCompoundPredicate(andPredicateWithSubpredicates: [subPred3])
let predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [and_pred1, and_pred2])
return CKQuery(recordType: "Recipe", predicate: predicate)
}
func GetRecipesWithoutLikedIds() -> CKQuery {
let searchTextA: [String] = [carbohydrate," "+carbohydrate,carbohydrate+"s",carbohydrate+"es"]
let subPred1 = NSPredicate (format: "ANY ingredients IN %#",argumentArray: [searchTextA])
let searchTextB: [String] = [vegetable," "+vegetable,vegetable+"s",vegetable+"es"]
let subPred2 = NSPredicate (format: "ANY ingredients IN %#",argumentArray: [searchTextB])
let likedIds: [Int] = [13733,32441]
let subPred3 = NSPredicate (format: "recipe_id IN %#",argumentArray: [likedIds])
let and_pred1 = NSCompoundPredicate(andPredicateWithSubpredicates: [subPred1, subPred2])
let and_pred2 = NSCompoundPredicate(andPredicateWithSubpredicates: [subPred3])
let predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [and_pred1, and_pred2])
return CKQuery(recordType: "Recipe", predicate: predicate)
}
func PrettyPrintRecipes(rName: String, rId: String, rIng: [String]) {
print("Name: "+rName)
print("Recipe_id: "+rId)
print("Ingredients:")
for s in 0..<rIng.count {
print("\t"+String(s)+": "+rIng[s])
}
}
public func printVegetable(){
print(vegetable)
}
}
An Example Image of my Dataset
I'm trying to load sleep data from healthkit.
after retrieving some data, I converted it into Double type to use chart, and reflected them on setChart function.
But here's some problem.
To successfully show on chart, my function should executed in order.
Ideal order is : retrieve data, convert data -> setchart
but the order is not kept.
I read some articles about dispatchqueue, but still I can't solve the problem.
What should I do to solve this problem? \
override func viewDidLoad() {
super.viewDidLoad()
//선행작업
DispatchQueue.global(qos: .userInteractive).sync {
print("1")
self.retrieveSleepAnalysis()
}
DispatchQueue.global(qos: .default).sync {
print("2")
self.recentSleepStartHourDouble = self.stringTimeToDouble(stringTime: self.recentSleepStartHour)
self.wakeUp = self.wakeupTimeCalcuation(start: self.recentSleepStartHourDouble, end: self.resultToSleepAmount)
}
DispatchQueue.main.async {
// self.recentSleepStartHourDouble = self.stringTimeToDouble(stringTime: self.recentSleepStartHour)
// self.wakeUp = self.wakeupTimeCalcuation(start: self.recentSleepStartHourDouble, end: self.resultToSleepAmount)
self.setChart(days: self.recentSleepDate.reversed(), sleepTimes: self.recentSleepStartHourDouble.reversed(), wakeupTimes:
public func retrieveSleepAnalysis() {
// first, we define the object type we want
if let sleepType = HKObjectType.categoryType(forIdentifier: HKCategoryTypeIdentifier.sleepAnalysis) {
// print(sleepType)
// Use a sortDescriptor to get the recent data first
let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: false)
// we create our query with a block completion to execute
let query = HKSampleQuery(sampleType: sleepType, predicate: nil, limit: 7, sortDescriptors: [sortDescriptor]) { (query, tmpResult, error) -> Void in
if error != nil {
// something happened
return
}
if let result = tmpResult {
for item in result {
if let sample = item as? HKCategorySample {
let value = (sample.value == HKCategoryValueSleepAnalysis.inBed.rawValue) ? "InBed" : "Asleep"
print("Healthkit sleep: \(sample.startDate) \(sample.endDate) - value: \(value)")
let sleepHour = Calendar.current.component(.hour, from: sample.startDate)
print("현지시각으로 잠든시간 \(sleepHour)")
if sleepHour < 19 && sleepHour > 12{
print("낮잠")
}
else{
self.resultToSleepAmount.append(CFDateGetTimeIntervalSinceDate(sample.endDate as CFDate, sample.startDate as CFDate)/3600)
let myDateFormatter = DateFormatter()
myDateFormatter.dateFormat = "MM / dd"
myDateFormatter.locale = Locale(identifier: "ko_KR")
let sleepDate = myDateFormatter.string(from: sample.startDate)
self.recentSleepDate.append(sleepDate)
let myHourFormatter = DateFormatter()
myHourFormatter.dateFormat = "HHmm"
myHourFormatter.locale = Locale(identifier: "ko_KR")
let sleepStartHour = myHourFormatter.string(from: sample.startDate)
self.recentSleepStartHour.append(sleepStartHour)
print("잠든 시간은 몇시몇분? \(sleepStartHour)")
let sleepEndHour = myHourFormatter.string(from: sample.endDate)
self.recentSleepEndHour.append(sleepEndHour)
}
}
print("total amount of sleep time : \(self.resultToSleepAmount), 현재 크기는 : \(self.resultToSleepAmount.count)")
}
}
}
// finally, we execute our query
healthStore.execute(query)
}
I don't quite understand what I am doing wrong since I am very new to MVVM. It worked in MVC architecture. I've setup my VM and am able to get the first set of results and even then that's not working properly. I get 4 results instead of 10 which is what LOADLIMIT is set as. I was able to get it to work in an MVC architecture without any issues. The VM function which triggers the query is called multiple (3) times instead of just once i.e. even prior to scrolling.
Here is my VM:
enum FetchRestaurant {
case success
case error
case location
case end
}
class ListViewModel {
let restaurant: [Restaurant]?
let db = Firestore.firestore()
var restaurantArray = [Restaurant]()
var lastDocument: DocumentSnapshot?
var currentLocation: CLLocation?
typealias fetchRestaurantCallback = (_ restaurants: [Restaurant]?, _ message: String?, _ status: FetchRestaurant) -> Void
var restaurantFetched: fetchRestaurantCallback?
var fetchRestaurant: FetchRestaurant?
init(restaurant: [Restaurant]) {
self.restaurant = restaurant
}
func fetchRestaurantCallback (callback: #escaping fetchRestaurantCallback) {
self.restaurantFetched = callback
}
func fetchRestaurants(address: String) {
print("address received: \(address)")
getLocation(from: address) { location in
if let location = location {
self.currentLocation = location
self.queryGenerator(at: location)
} else {
self.restaurantFetched?(nil, nil, .location)
}
}
}
func queryGenerator(at location: CLLocation) {
var query: Query!
if restaurantArray.isEmpty {
query = db.collection("Restaurant_Data").whereField("distributionType", isLessThanOrEqualTo: 2).limit(to: Constants.Mealplan.LOADLIMIT)
} else {
print("last document:\(String(describing: lastDocument?.documentID))")
query = db.collection("Restaurant_Data").whereField("distributionType", isLessThanOrEqualTo: 2).start(afterDocument: lastDocument!).limit(to: Constants.Mealplan.LOADLIMIT)
}
batchFetch(query: query)
}
func batchFetch(query: Query) {
query.getDocuments { (querySnapshot, error) in
if let error = error {
self.restaurantFetched?(nil, error.localizedDescription, .error)
} else if querySnapshot!.isEmpty {
self.restaurantFetched?(nil, nil, .end)
} else if !querySnapshot!.isEmpty {
let queriedRestaurants = querySnapshot?.documents.compactMap { querySnapshot -> Restaurant? in
return try? querySnapshot.data(as: Restaurant.self)
}
guard let restaurants = queriedRestaurants,
let currentLocation = self.currentLocation else {
self.restaurantFetched?(nil, nil, .end)
return }
self.restaurantArray.append(contentsOf: self.applicableRestaurants(allQueriedRestaurants: restaurants, location: currentLocation))
DispatchQueue.main.asyncAfter(deadline: .now(), execute: {
self.restaurantFetched?(self.restaurantArray, nil, .success)
})
self.lastDocument = querySnapshot!.documents.last
}
}
}
func getLocation(from address: String, completionHandler: #escaping (_ location: CLLocation?) -> Void) {
let geocoder = CLGeocoder()
geocoder.geocodeAddressString(address) { (placemarks, error) in
guard let placemarks = placemarks,
let location = placemarks.first?.location else {
completionHandler(nil)
return
}
completionHandler(location)
}
}
}
And in the VC viewDidLoad:
var fetchMore = false
var reachedEnd = false
let leadingScreensForBatching: CGFloat = 5.0
var searchController = UISearchController(searchResultsController: nil)
var currentAddress : String?
var listViewModel = ListViewModel(restaurant: [Restaurant]())
override func viewDidLoad() {
super.viewDidLoad()
listViewModel.fetchRestaurantCallback { (restaurants, error, result) in
switch result {
case .success :
self.loadingShimmer.stopShimmering()
self.loadingShimmer.removeFromSuperview()
guard let fetchedRestaurants = restaurants else { return }
self.restaurantArray.append(contentsOf: fetchedRestaurants)
self.tableView.reloadData()
self.fetchMore = false
case .location :
self.showAlert(alertTitle: "No businesses nearby", message: "Try going back and changing the address")
case .error :
guard let error = error else { return }
self.showAlert(alertTitle: "Error", message: error)
case .end :
self.fetchMore = false
self.reachedEnd = true
}
}
if let currentAddress = currentAddress {
listViewModel.fetchRestaurants(address: currentAddress)
}
}
I would really appreciate links or resources for implementing MVVM in Swift for a Firestore back-end. I'm coming up short on searches here and on Google. Even tried medium.
EDIT
class ListViewController: UITableViewController {
lazy var loadingShimmer: UIImageView = {
let image = UIImage(named: "shimmer_background")
let imageview = UIImageView(image: image)
imageview.contentMode = .top
imageview.translatesAutoresizingMaskIntoConstraints = false
return imageview
}()
var restaurantArray = [Restaurant]()
var planDictionary = [String: Any]()
var fetchMore = false
var reachedEnd = false
let leadingScreensForBatching: CGFloat = 5.0
var searchController = UISearchController(searchResultsController: nil)
var currentAddress : String?
var listViewModel = ListViewModel(restaurant: [Restaurant]())
override func viewDidLoad() {
super.viewDidLoad()
setupTable()
}
override func viewWillAppear(_ animated: Bool) {
clearsSelectionOnViewWillAppear = false
}
func setupTable() {
navigationItem.backBarButtonItem = UIBarButtonItem(title: "Restaurant", style: .plain, target: nil, action: nil)
tableView.register(RestaurantCell.self, forCellReuseIdentifier: "Cell")
tableView.delegate = self
tableView.dataSource = self
let navigationBarHeight: CGFloat = self.navigationController!.navigationBar.frame.height
tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: -navigationBarHeight, right: 0)
tableView.separatorStyle = .none
tableView.showsVerticalScrollIndicator = false
tableView.addSubview(loadingShimmer)
loadingShimmer.topAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.topAnchor).isActive = true
loadingShimmer.leadingAnchor.constraint(equalTo: tableView.leadingAnchor).isActive = true
loadingShimmer.trailingAnchor.constraint(equalTo: tableView.trailingAnchor).isActive = true
loadingShimmer.startShimmering()
initialSetup()
}
func initialSetup() {
let addressOne = planDictionary["addressOne"] as! String + ", "
let city = planDictionary["city"] as! String + ", "
let postalCode = planDictionary["postalCode"] as! String
currentAddress = addressOne + city + postalCode
setupSearch()
listViewModel.fetchRestaurantCallback { (restaurants, error, result) in
switch result {
case .success :
self.loadingShimmer.stopShimmering()
self.loadingShimmer.removeFromSuperview()
guard let fetchedRestaurants = restaurants else { return }
self.restaurantArray.append(contentsOf: fetchedRestaurants)
self.tableView.reloadData()
self.fetchMore = false
case .location :
self.showAlert(alertTitle: "No businesses nearby", message: "Try going back and changing the address")
case .error :
guard let error = error else { return }
self.showAlert(alertTitle: "Error", message: error)
case .end :
self.fetchMore = false
self.reachedEnd = true
}
}
if let currentAddress = currentAddress {
listViewModel.fetchRestaurants(address: currentAddress)
}
}
override func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let off = scrollView.contentOffset.y
let off1 = scrollView.contentSize.height
if off > off1 - scrollView.frame.height * leadingScreensForBatching {
print("\(fetchMore), \(reachedEnd)")
if !fetchMore && !reachedEnd {
if let address = self.currentAddress {
print("address sent: \(address)")
listViewModel.fetchRestaurants(address: address)
}
}
}
}
}
That you're only getting back 4 results instead of 10 is not due to a faulty query or get-document request—those are coded properly. You're either losing documents when you parse them (some are failing Restaurant initialization), Constants.Mealplan.LOADLIMIT is wrong, or there aren't more than 4 documents in the collection itself that satisfy the query.
That the query is executed 3 times instead of once is also not due to anything in this code—viewDidLoad is only called once and geocodeAddressString only returns once. You're making a fetch request elsewhere that we can't see.
In the batchFetch method, you have a guard that returns out of the function without ever calling its completion handler. This will leave the UI in a state of limbo. I'd recommend always calling the completion handler no matter why the function returns.
You never manage the document cursor. If the get-document return has less documents than the load limit, then nil the last-document cursor. This way, when you attempt to get the next page of documents, guard against a nil cursor and see if there is even more to fetch.
There's no need to pass in an empty array and have your function fill it; simply construct and return an array of results within ListViewModel itself.
We can't see how you trigger pagination. Is it through a scroll delegate when the user reaches the bottom or through a button tap, for example? If it's through a scroll delegate, then I'd disable that for now and see how many returns you get—I suspect one, instead of 3.
What is the particular reason you've ditched MVC for MVVM here? With MVC, you can get pagination up with just a few lines of code. I think MVVM is overkill for iOS applications and would advise against using it unless you have a compelling reason.
I am trying to get last 7 days step count but it is always coming zero. But when I open the health app in iPhone then it is more than 3000 steps. Even I also added property Privacy - Health Share Usage Description and Privacy - Health Update Usage Description in .plist file.
Here is my code
var healthScore = HKHealthStore()
override func viewDidLoad() {
super.viewDidLoad()
// Access Step Count
let healthKitTypes: Set = [ HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)! ]
// Check for Authorization
healthScore.requestAuthorization(toShare: healthKitTypes, read: healthKitTypes) { (bool, error) in
if (bool) {
// Authorization Successful
self.getSteps { (result) in
DispatchQueue.main.async {
let stepCount = String(Int(result))
self.stepLbl.text = String(stepCount)
}
}
}
}
}
func getSteps(completion: #escaping (Double) -> Void){
let stepsQuantityType = HKQuantityType.quantityType(forIdentifier: .stepCount)!
let now = Date()
let exactlySevenDaysAgo = Calendar.current.date(byAdding: DateComponents(day: -7), to: now)!
let predicate = HKQuery.predicateForSamples(withStart: exactlySevenDaysAgo, end: now, options: .strictStartDate)
let query = HKStatisticsQuery(quantityType: stepsQuantityType, quantitySamplePredicate: predicate, options: .cumulativeSum) { (_, result, error) in
var resultCount = 0.0
guard let result = result else {
print("\(String(describing: error?.localizedDescription)) ")
completion(resultCount)
return
}
if let sum = result.sumQuantity() {
resultCount = sum.doubleValue(for: HKUnit.count())
}
DispatchQueue.main.async {
completion(resultCount)
}
}
healthScore.execute(query)
}
In console I checked the dates are also correct now here's the screenshot