I'm attempting to use Tony Million's Reachability within a new Swift based app. I have it implemented in another app I wrote in Obj C, but I'm having issues with getting the proper syntax in Swift. The code blocks are as follows:
override func viewDidLoad() {
super.viewDidLoad()
messageText.text = ""
var reach: Reachability = Reachability(hostName: "www.apple.com")
NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityChanged", name: kReachabilityChangedNotification, object: nil)
reach.reachableBlock = Reachability()
{
dispatch_async(dispatch_get_main_queue(), {
self.messageText.text = "Enter search criteria...";
})
}
reach.unreachableBlock = Reachability()
{
dispatch_async(dispatch_get_main_queue(), {
self.messageText.text = "Attempting to contact network...";
})
}
reach.startNotifier()
}
AND
func reachabilityChanged(note: NSNotification)
{
var reach: Reachability = Reachability()
if(reach.isReachable())
{
messageText.text = "Enter search criteria...";
}
else
{
messageText.text = "Attempting to contact network...";
}
}
My issues are first, my "blocks" for "reachable" and "unreachable" are not the correct syntax and I'm at a loss for what is the proper syntax for these blocks. My second issue is with the "reachabilityChanged" function. I get an error stating "-[_TtC9icdDRPlus20SearchViewController reachabilityChanged]: unrecognized selector sent to instance" which I'm again at a loss. Condsider my Obj C code as follows:
-(void)viewDidLoad
{
[super viewDidLoad];
NSString *popUpShownOnce = #"YES";
NSInteger swipeCount = 0;
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:popUpShownOnce forKey:#"popDisplayed"];
[defaults setInteger:swipeCount forKey:#"showswipearrows"];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(reachabilityChanged:)
name:kReachabilityChangedNotification
object:nil];
[[UIApplication sharedApplication] setStatusBarHidden:NO];
Reachability * reach = [Reachability reachabilityWithHostname:#"somesite.com"];
reach.reachableBlock = ^(Reachability * reachability)
{
dispatch_async(dispatch_get_main_queue(), ^{
searchForText.placeholder = #"Enter search criteria...";
});
};
reach.unreachableBlock = ^(Reachability * reachability)
{
dispatch_async(dispatch_get_main_queue(), ^{
searchForText.placeholder = #"Attempting to contact network...";
});
};
[reach startNotifier];
}
-(void)reachabilityChanged:(NSNotification*)note
{
Reachability * reach = [note object];
if([reach isReachable])
{
searchForText.placeholder = #"Enter search criteria...";
}
else
{
searchForText.placeholder = #"Attempting to contact network...";
}
}
Assistance is greatly appreciated. The questions are as follows:
1. What is the proper translation for the reachable and unreachable blocks from Obj C to Swift?
2. If my addObserver call is correct, why might I get the unrecognized selector error? If not correct, what is the proper call?
Thanks in advance.
The correct syntax for closures is { (<params>) -> <return type> in <statements> }:
reach.reachableBlock = { (reachability) in
dispatch_async(dispatch_get_main_queue(), {
self.messageText.text = "Enter search criteria...";
})
}
With NSNotificationCenter, looks like you missed the colon in the selector argument:
NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityChanged:", name: kReachabilityChangedNotification, object: nil)
Your error after making the changes that #Austin recommended is that self.reachabilityRef in SCNetworkReachabilitySetCallback is NULL.
try:
func reachabilityChanged(note: NSNotification!) {
var reach: Reachability! = Reachability(reachabilityRef: note.object as SCNetworkReachability)
if(reach.isReachable()) {
messageText.text = "Enter search criteria...";
} else {
messageText.text = "Attempting to contact network...";
}
}
UPDATE:
It would seem that SCNetworkReachability is not currently fully working with Swift: according to this: https://twitter.com/marksands/status/474717606004273152
I got it to work like this:
var reachability: Reachability?
override func viewDidLoad() {
super.viewDidLoad()
// Setup reachability
reachability = Reachability(hostName: "www.google.com")
reachability!.reachableBlock = { (reach) in
dispatch_async(dispatch_get_main_queue(), {
self.titleLabel.attributedText = Utilities.myAttributedText("Online", mySize: 18, myFont: "HelveticaNeue", myColor: UIColor.whiteColor())
self.titleLabel.sizeToFit()
})
}
reachability!.unreachableBlock = { (reach) in
dispatch_async(dispatch_get_main_queue(), {
self.titleLabel.attributedText = Utilities.myAttributedText("Offline", mySize: 18, myFont: "HelveticaNeue", myColor: UIColor.whiteColor())
self.titleLabel.sizeToFit()
})
}
reachability!.startNotifier()
}
this worked for me:
//Reachability
myReachabilityInstance = Reachability(hostName: "www.google.com")
myReachabilityInstance?.reachableOnWWAN = false
NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityDidChangeMethod", name: kReachabilityChangedNotification, object: nil)
myReachabilityInstance?.startNotifier()
Related
I would like to implement the UIContextMenuConfiguration in objC
There are many examples in swift , but I have to close a matter in objc ...
So in swift I found examples like this
override func tableView(_ tableView: UITableView, contextMenuConfigurationForRowAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
let configuration = UIContextMenuConfiguration(identifier: nil, previewProvider: nil) { actions -> UIMenu<UIAction>? in
let action = UIAction(__title: "Custom action", image: nil, options: []) { action in
// Put button handler here
}
return UIMenu<UIAction>.create(title: "Menu", children: [action])
}
return configuration
}
In objc I can not define the actions
I can only produce mistakes ...
this is my example code...
- (UIContextMenuConfiguration *)tableView:(UITableView *)tableView
contextMenuConfigurationForRowAtIndexPath:(NSIndexPath *)indexPath
point:(CGPoint)point API_AVAILABLE(ios(13.0)){
BlogPost *blogPost = [self.blogPosts objectAtIndex:indexPath.row];
UIAction * lettura = [UIAction actionWithTitle:#"Leggi"
image:nil
identifier:nil
handler:^(UIAction *action){[self presentSF:indexPath];}
];
UIMenu * menu = [UIMenu menuWithTitle:#"" children:#[lettura]];
UIContextMenuConfiguration * config = [UIContextMenuConfiguration configurationWithIdentifier:nil
previewProvider:^ UIViewController* {
SFSafariViewController *previewSFController = [[SFSafariViewController alloc] initWithURL:blogPost.url entersReaderIfAvailable:NO];
previewSFController.preferredControlTintColor=[UIColor blackColor];
previewSFController.delegate = self;
return previewSFController;
}
actionProvider:nil];
return config;
}
Someone can help me
Thank you so much in advance for your help
Vanni
Sorry you people
I solved ...
I just had to pass an array...
actionProvider:^(NSArray* suggestedAction){return menu;}
- (UIContextMenuConfiguration*)tableView:(UITableView*)tableView contextMenuConfigurationForRowAtIndexPath:(NSIndexPath*)indexPath point:(CGPoint)point
{
UIContextMenuConfiguration* config = [UIContextMenuConfiguration configurationWithIdentifier:nil
previewProvider:nil
actionProvider:^UIMenu* _Nullable(NSArray<UIMenuElement*>* _Nonnull suggestedActions) {
NSMutableArray* actions = [[NSMutableArray alloc] init];
//Your Action
[actions addObject:[UIAction actionWithTitle:#"Favoritar!" image:[UIImage systemImageNamed:#"star"] identifier:nil handler:^(__kindof UIAction* _Nonnull action) {
[self updateFavoriteTournament:self.tournamentArray[indexPath.row][#"_id"]];
}]];
UIMenu* menu = [UIMenu menuWithTitle:#"" children:actions];
return menu;
}];
return config;
}
Its bit early to ask but I'm planning to add feature specially for FaceID, so before that I need to validate either device support FaceID or not?
Need suggestion and help.
Thanks in advance.
Objective-C version
- (BOOL) isFaceIdSupported{
if (#available(iOS 11.0, *)) {
LAContext *context = [[LAContext alloc] init];
if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:nil]){
return ( context.biometryType == LABiometryTypeFaceID);
}
}
return NO;
}
I found that you have to call canEvaluatePolicy before you will properly get the biometry type. If you don't you'll always get 0 for the raw value.
So something like this in Swift 3, tested and working in Xcode 9.0 & beta 9.0.1.
class func canAuthenticateByFaceID () -> Bool {
//if iOS 11 doesn't exist then FaceID doesn't either
if #available(iOS 11.0, *) {
let context = LAContext.init()
var error: NSError?
if context.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error: &error) {
//As of 11.2 typeFaceID is now just faceID
if (context.biometryType == LABiometryType.typeFaceID) {
return true
}
}
}
return false
}
You could of course write that just to see if it's either biometric and return the type along with the bool but this should be more than enough for most to work off of.
Thanks Ashley Mills, I created a function to detect FaceID in Device.
- (BOOL)canAuthenticateByFaceID {
LAContext *context = [[LAContext alloc] init];
if context.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error: &error) {
if (context.biometryType == LABiometryTypeFaceID && #available(iOS 11.0, *)) {
return YES;
} else {
return NO;
}
}
}
Hope this will help other. Happy coding!!
Finally I wrote my own Library for detecting FaceID here you find
Swift 4 compatible version
var isFaceIDSupported: Bool {
if #available(iOS 11.0, *) {
let localAuthenticationContext = LAContext()
if localAuthenticationContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) {
return localAuthenticationContext.biometryType == .faceID
}
}
return false
}
+(BOOL)supportFaceID
{
LAContext *myContext = [[LAContext alloc] init];
NSError *authError = nil;
// call this method only to get the biometryType and we don't care about the result!
[myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError];
NSLog(#"%#",authError.localizedDescription);
if (#available(iOS 11.0, *)) {
return myContext.biometryType == LABiometryTypeFaceID;
} else {
// Device is running on older iOS version and OFC doesn't have FaceID
return NO;
}
}
These two function calls seem to be conflicting:
MagicalRecord.save({ (localContext) in
let items = NewsItem.staleNewsItems(in: localContext)
if ((items?.count)! > 0){
items?.forEach({ (item) in
if let object = item as? NSManagedObject {
object.mr_deleteEntity(in: localContext)
}
})
}
})
and
- (void) buildAndFetchFRCsInContext:(NSManagedObjectContext*)context {
self.newsItemsFRC = [self buildFetchResultsControllerForClass:[NewsItem class] sortedBy:#"id" withPredicate:nil inContext:context];
[context performBlock:^{
__unused NSDate* start = [NSDate date];
NSError* error;
[self.newsItemsFRC performFetch:&error]; // this line crashes
[self calculateAndBroadcastCounts];
}];
}
Is this save call thread safe? If so what could cause these two functions to cause each-other to crash?
The issue is I'm modifying the news items outside of the context they were created in. So to fix the issue I had to move the code to the main thread. I switched from using magical records save to just performBlockAndWait which is guaranteed to run on the calling thread:
private static func cleanUpNewsItems() -> Void {
let context = NSManagedObjectContext.mr_()
context.performAndWait {
var itemsToDelete = [NSManagedObject]()
if let items = NewsItem.staleNewsItems(in: context) {
items.forEach({ (item) in
itemsToDelete.append(item as! NSManagedObject)
})
}
for item in itemsToDelete {
context.delete(item)
}
do {
try context.save()
} catch let error as NSError {
print("Error While Deleting Note: \(error.userInfo)")
}
}
}
I am trying to re-write an app in swift which is currently in Objective-C. How would I change this single line into Swift, as my current attempt does not prove correct
Tabata *tabata = [notification object];
Here is the entire function:
- (void)stateChanged:(NSNotification*)notification
{
if (enabled)
{
Tabata *tabata = [notification object];
switch (tabata.getState) {
case EXERCISE:
case RELAXATION:
[player play];
break;
default:
break;
}
}
}
And here is what I've converted into Swift:
func stateChanged(notifcation: NSNotification) {
if enabled {
var tabata: Tabata! = notification.object //error "Use of unresolved identifier 'notification'"
switch tabata.getState() {
case .EXERCISE: fallthrough
case .RELAXATION:
player.play()
break
default:
break
}
}
}
In Swift you have to downcast objects of type AnyObject rather then declare the type
var tabata = notification.object as! Tabata
func stateChanged(notification: NSNotification) {
if(enabled) {
var tabata: Tabata = notification.object as! Tabata
switch tabata.getState() {
case .EXERCISE:
fallthrough
case .RELAXATION:
player.play()
break
default:
break
}
}
}
Hope this helps!
in my app i have an array of CALayer that I have animated along a bezierPath. When I close and reopen the app my layers are not animating and not in the same position as before closing the app. I have implemented two methods, pauseLayer and resumeLayer that works when I trigger them with two buttons inside my app but they won't work after closing the app. The code is the following
- (void)pauseLayers{
for(int y=0; y<=end;y++)
{
CFTimeInterval pausedTime = [car[y] convertTime:CACurrentMediaTime() fromLayer:nil];
car[y].speed = 0.0;
car[y].timeOffset = pausedTime;
standardUserDefaults[y] = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults[y]) {
[standardUserDefaults[y] setDouble:pausedTime forKey:#"pausedTime"];
[standardUserDefaults[y] synchronize];
}
NSLog(#"saving positions");
}
}
-(void)resumeLayers
{
for(int y=0; y<=end;y++)
{
standardUserDefaults[y] = [NSUserDefaults standardUserDefaults];
car[y].timeOffset = [standardUserDefaults[y] doubleForKey:#"pausedTime"];
CFTimeInterval pausedTime = [car[y] timeOffset];
car[y].speed = 1.0;
car[y].timeOffset = 0.0;
car[y].beginTime = 0.0;
CFTimeInterval timeSincePause = [car[y] convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
car[y].beginTime = timeSincePause;
}
}
- (void)applicationDidEnterBackground:(UIApplication *)application {
mosquitosViewController *mvc = [[mosquitosViewController alloc] init];
[mvc pauseLayers];
}
The problem with what you are trying to do above is that you are creating a completely new instance of your view controller, which is not the one that was showing onscreen. That's why nothing happens when you send the pauseLayers message.
What you should do is register to receive notifications for when your app goes to and comes from the background and call the appropriate methods (pauseLayers and resumeLayers) when that notification arrives.
You should add the following code somewhere in your mosquitosViewController implementation (I usually do so in viewDidLoad):
// Register for notification that app did enter background
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(pauseLayers)
name:UIApplicationDidEnterBackgroundNotification
object:[UIApplication sharedApplication]];
// Register for notification that app did enter foreground
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(resumeLayers)
name:UIApplicationWillEnterForegroundNotification
object:[UIApplication sharedApplication]];
I write a Swift 4 version extension based on #cclogg and #Matej Bukovinski answers from this thread. All you need is to call layer.makeAnimationsPersistent()
Full Gist here: CALayer+AnimationPlayback.swift, CALayer+PersistentAnimations.swift
Core part:
public extension CALayer {
static private var persistentHelperKey = "CALayer.LayerPersistentHelper"
public func makeAnimationsPersistent() {
var object = objc_getAssociatedObject(self, &CALayer.persistentHelperKey)
if object == nil {
object = LayerPersistentHelper(with: self)
let nonatomic = objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC
objc_setAssociatedObject(self, &CALayer.persistentHelperKey, object, nonatomic)
}
}
}
public class LayerPersistentHelper {
private var persistentAnimations: [String: CAAnimation] = [:]
private var persistentSpeed: Float = 0.0
private weak var layer: CALayer?
public init(with layer: CALayer) {
self.layer = layer
addNotificationObservers()
}
deinit {
removeNotificationObservers()
}
}
private extension LayerPersistentHelper {
func addNotificationObservers() {
let center = NotificationCenter.default
let enterForeground = NSNotification.Name.UIApplicationWillEnterForeground
let enterBackground = NSNotification.Name.UIApplicationDidEnterBackground
center.addObserver(self, selector: #selector(didBecomeActive), name: enterForeground, object: nil)
center.addObserver(self, selector: #selector(willResignActive), name: enterBackground, object: nil)
}
func removeNotificationObservers() {
NotificationCenter.default.removeObserver(self)
}
func persistAnimations(with keys: [String]?) {
guard let layer = self.layer else { return }
keys?.forEach { (key) in
if let animation = layer.animation(forKey: key) {
persistentAnimations[key] = animation
}
}
}
func restoreAnimations(with keys: [String]?) {
guard let layer = self.layer else { return }
keys?.forEach { (key) in
if let animation = persistentAnimations[key] {
layer.add(animation, forKey: key)
}
}
}
}
#objc extension LayerPersistentHelper {
func didBecomeActive() {
guard let layer = self.layer else { return }
restoreAnimations(with: Array(persistentAnimations.keys))
persistentAnimations.removeAll()
if persistentSpeed == 1.0 { // if layer was playing before background, resume it
layer.resumeAnimations()
}
}
func willResignActive() {
guard let layer = self.layer else { return }
persistentSpeed = layer.speed
layer.speed = 1.0 // in case layer was paused from outside, set speed to 1.0 to get all animations
persistAnimations(with: layer.animationKeys())
layer.speed = persistentSpeed // restore original speed
layer.pauseAnimations()
}
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
NSLog(#"1");
mosquitosViewController *mvc = [[mosquitosViewController alloc] init];
[mvc pauseLayers];
/*
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
*/
}
See my answer to this post for details on how to restart an animation after multitasking:
Restoring animation where it left off when app resumes from background