I have a class with an object incall. I have a method that sets it and another methods that runs a method available for that object.
Here is my header file:
#interface RCTPlivo : NSObject <PlivoEndpointDelegate, CXProviderDelegate>
#property (nonatomic) PlivoIncoming *incall;
#property (nonatomic) PlivoEndpoint *endpoint;
#end
And here is my implementation file:
#implementation RCTPlivo
- (void)login {
endpoint = [[PlivoEndpoint alloc] init];
[endpoint login:plivoUser AndPassword:plivoPass];
endpoint.delegate = self;
}
- (void)triggerIncomingCall {
...
CXProvider *callkitProvider = [[CXProvider alloc] initWithConfiguration: configuration];
[callkitProvider setDelegate:self queue:nil];
...
[callkitProvider reportNewIncomingCallWithUUID:currentCall update:update completion:^(NSError * _Nullable error) {
if (error) {
NSLog(#"Error: %#", error);
}
}];
}
- (void)onIncomingCall:(PlivoIncoming *)incoming {
// setting
self.incall = incoming
}
- (void)provider:(CXProvider *)provider performAnswerCallAction:(CXAnswerCallAction *)action
{
// Here self.incall is null
[self.incall answer];
}
#end
When i log self.incall in perfromAnswerCall delegate it's null. When I log it in the onIncomingCall delegate the variable is set.
What am I missing here?
Update
Added the code that initializes the delegates and removed ivars.
Your interface should be:
#interface RCTPlivo : NSObject <PlivoEndpointDelegate>
#property (nonatomic, strong) PlivoIncoming *incall;
#end
and your implementation should be:
#implementation RCTPlivo
- (void)onIncomingCall:(PlivoIncoming *)incoming {
self.incall = incoming;
}
- (void)provider:(CXProvider *)provider performAnswerCallAction:(CXAnswerCallAction *)action {
[self.incall answer];
}
#end
One way this can happen is that you somehow have two separate instances of RCTPlivo. Try stopping the debugger in each of those calls and in the debugger do:
(lldb) po self
If everything's ok then the addresses should be the same.
The infall property is not defined as strong. So we can assume that there is no strong reference to the original object outside this method and it was released.
Update
This property was mentioned as delegate so its weak nature can be a designated behaviour and if this is an option the message sender should have a strong property holding the object reference.
Related
My app currently uses this deprecated function:
id unarchivedObject=[NSKeyedUnarchiver unarchiveObjectWithData:codedData];
if([unarchivedObject isKindOfClass:[NSDictionary class]]){
// currently returns TRUE when reading existing user data.
}
To update, I've converted to this:
id unarchivedObject=[NSKeyedUnarchiver unarchivedObjectOfClass:[NSDictionary class] fromData:codedData error:nil];
if([unarchivedObject isKindOfClass:[NSDictionary class]]){
// currently returns FALSE when reading existing user data.
}
The data was originally encoded like this:
-(void)encodeWithCoder:(NSCoder*)encoder{
[encoder encodeObject:text forKey:#"text"];
}
-(instancetype)initWithCoder:(NSCoder*)decoder{
if(self=[super init]){
text=[decoder decodeObjectForKey:#"text"];
}
What could be causing the IF statement to return FALSE using the newer code?
Please note that I am concerned primarily with reading existing data stored prior to deprecating the Archiving functions. Simply changing to the newer functions does not resolve the issue.
Interesting question! I've been supporting iOS 10.0 so I haven't encountered such issue until I saw this. I was tinkering for an hour and I successfully found the issue.
What could be causing the IF statement to return FALSE using the newer
code?
It's because your unarchivedObject object is nil!
If you use the parameter error in the new method, you would see an error like this:
Error Domain=NSCocoaErrorDomain Code=4864 "This decoder will only
decode classes that adopt NSSecureCoding. Class 'QTPerson' does not
adopt it." UserInfo={NSDebugDescription=This decoder will only decode
classes that adopt NSSecureCoding. Class 'QTPerson' does not adopt it.
But how do we get the correct value for this unarchivedObject and not nil? It would take a couple of steps.
First off, make your model/class conform to <NSCoding, NSSecureCoding>
Example:
QTPerson.h
#import <Foundation/Foundation.h>
#class QTPerson;
NS_ASSUME_NONNULL_BEGIN
#pragma mark - Object interfaces
#interface QTPerson : NSObject <NSCoding, NSSecureCoding>
#property (nonatomic, copy) NSString *text;
#end
NS_ASSUME_NONNULL_END
And then implement the protocol methods:
QTPerson.m
#import "QTPerson.h"
#implementation QTPerson
+ (BOOL)supportsSecureCoding {
return YES;
}
- (void)encodeWithCoder:(NSCoder *)coder {
[coder encodeObject:_text forKey:#"text"];
}
- (instancetype)initWithCoder:(NSCoder *)coder {
self = [super init];
if (self) {
_text = [coder decodeObjectOfClass:[NSString class] forKey:#"text"];
}
return self;
}
#end
And then when archiving an object, you would want to pass YES to the parameter requiringSecureCoding, like so:
QTPerson *person = [[QTPerson alloc] init];
person.text = #"Glenn";
NSData *codedData1 = [NSKeyedArchiver archivedDataWithRootObject:person requiringSecureCoding:YES error:nil];
[[NSUserDefaults standardUserDefaults] setValue:codedData1 forKey:#"boom"];
Lastly, when unarchiving, just do what you did correctly, like so:
NSData *codedData = [[NSUserDefaults standardUserDefaults] dataForKey:#"boom"];
NSError *er;
id unarchivedObject=[NSKeyedUnarchiver unarchivedObjectOfClass:[QTPerson class] fromData:codedData error:&er];
if([unarchivedObject isKindOfClass:[QTPerson class]]){
NSLog(#"TRUE!");
} else {
NSLog(#"FALSE!");
}
Voila! You'll get nonnull object unarchivedObject, hence the TRUE/YES value you're looking for!
I'm attempting to access data from CMPedometer. I have a class called StepService which has the following property
#property (strong, nonatomic) CMPedometer *pedometer;
Which has the following getter
-(CMPedometer*) pedometer{
if(!_pedometer){
_pedometer = [[CMPedometer alloc] init];
}
return _pedometer;
}
I'm using the following code to get the steps:
-(void) storeData {
[self.pedometer queryPedometerDataFromDate:[[NSCalendar currentCalendar] startOfDayForDate:[NSDate date]]
toDate:[NSDate date]
withHandler:^(CMPedometerData *pedometerData, NSError *err){
if (err) {
NSLog(#"Error getting pedometer data: %#", err);
} else {
...
}
}];
}
When I call the above code like so:
StepService *stepService = [[StepService alloc] init];
[stepService storeData];
I get the following value for err
Error Domain=CMErrorDomain Code=103 "(null)"
Debugging reveals pedometer is not null but pedometerData is. What is going on here, how can I resolve this error?
Following Larme's advice, I created a property in my ViewController and synthesized it, like so:
#interface MainViewController(){
#property (strong, nonatomic) StepService *stepService;
#end
#implementation MainViewController
#synthesize stepService
I was then able to create and call the method containing queryPedometerDataFromDate like so:
stepService = [[StepService alloc] init];
[stepService storeData];
Ok, strange thing occurred and I guess answer is quite simple, but I fail to figure out what's going on.
Situation is next:
I have an NSObject class called Constants.
Constants.h
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import <GooglePlus/GooglePlus.h>
#interface Constants : NSObject
+(Constants*)shared;
#property GTLPlusPerson* googlePlusUser;
#property int profileType;
#property NSString *userName, *userLastName, *userEmail, *userGoogleId,*userProfilePicture;
#end
Constants.m
#import "Constants.h"
#implementation Constants
#synthesize profileType, userProfilePicture, userLastName,userName,userGoogleId,userEmail;
static Constants *constants = nil;
+ (Constants*)shared {
if (nil == constants) {
constants = [[Constants alloc] init];
}
return constants;
}
I use this class in order to save some static variables that I will use throughout the app.
Now, If I try and declare one of the variables like
[Constants shared].userName = #"name";
from an NSObject class method (Which I call from a ViewController), I fail to do so.
But If I declare Constant variables directly from ViewController (after viewDidLoad for example) everything works fine.
Here is the Class I try to declare variables from, but I fail (It also has singleton in it, that might be the source of the problem, but im not sure why would it)
#implementation GoogleLogin
static GoogleLogin* gLogin = nil;
+(GoogleLogin*)shared
{
if (nil == gLogin){
gLogin = [[[self class]alloc]init];
}
return gLogin;
}
-(void)getProfile
{
GTLServicePlus* plusService = [[GTLServicePlus alloc] init];
plusService.retryEnabled = YES;
[plusService setAuthorizer:[GPPSignIn sharedInstance].authentication];
GTLQueryPlus *query = [GTLQueryPlus queryForPeopleGetWithUserId:#"me"];
plusService.apiVersion=#"v1";
[plusService executeQuery:query
completionHandler:^(GTLServiceTicket *ticket,
GTLPlusPerson *person,
NSError *error) {
if (error){
NSLog(#"Error while fetching user profile: %#", error);
}else{
NSLog(#"User profile information fetched OK");
[Constants shared].googlePlusUser = person;
[Constants shared].profileType = 1;
[Constants shared].userName = person.name.givenName;
[Constants shared].userLastName = person.name.familyName;
[Constants shared].userEmail = [GPPSignIn sharedInstance].authentication.userEmail;
[Constants shared].userGoogleId = person.identifier;
[Constants shared].userProfilePicture = person.image.url;
NSLog(#"%# %# %# %# %# ",person.name.givenName,person.name.familyName,[GPPSignIn sharedInstance].authentication.userEmail,person.identifier,person.image.url);
}
}];
}
and this is how I call those methods, from my ViewController:
- (IBAction)signupWithGoogle:(UIButton *)sender {
//if i call this method here, on button click, it will finish all the steps needed, except setting constant variables
[[GoogleLogin shared] googleLoginFromViewController:self];
//if I uncomment next line, username will be declared and I will be able to access it later
//[Constants shared].userName = #"Petar";
}
Can anybody figure out why is this happening and what should I do to change that?
When you define a property is strongly suggested to declare the attributes to use with it. I guess the compiler should complain about this with a message like
No 'assign', 'retain', or 'copy' attribute is specified - 'assign' is
assumed
So, use the following instead (copy semantics is fine for mutable classes).
#property (nonatomic, copy) NSString *myString;
You should also specify if the property should be accessed in a atomic or nonatomic way. If you don't specify it, the former will be applied.
Then, you are using a singleton pattern. The suggested way is to use GCD like so.
+ (ConstantsManager*)sharedManager {
static ConstantsManager *sharedManager;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedManager = [[[self class] alloc] init];
});
return sharedManager;
}
Well you did not set your property attributes on the singleton class.
For example,
#property (nonatomic, strong, readonly) ...
Have you tried moving the property assignments out of the completionHandler? It may be that your properties are being assigned on a background thread and your view controller is not catching the assignment. An easy way to check is to override the setters and getters and put breakpoints in them to see what order they are being accessed.
1) Remove the #synthesize because it's not needed (properties will be synthesized as _property automatically)
2) Override setter & getter
-(void)setProfileType:(NSInteger)profileType {
_profileType = profileType;
}
-(NSInteger)profileType {
return _profileType;
}
3) Place breakpoints within these methods and see if the getter is being called before the setter. Alternatively, if simply moving the assignments out of the completionHandler fixes it you know you have some concurrency issues.
I suggest reading up on atomic/nonatomic properties, #synthesize and Objective-C concurrency.
So right now I'm working on sending the match data in a turn based game and I was using this post as a reference.
Good practices for Game Center matchData
I created a new class and it implements NSCoding. It currently only holds one variable for a NSString. This is the code for when I send the match data.
self.game.status = #"Test";
NSData *updatedMatchData = [NSKeyedArchiver archivedDataWithRootObject:self.game];
[self.currentMatch endTurnWithNextParticipants:[NSArray arrayWithObject:nextPerson]
turnTimeout:1000
matchData:updatedMatchData
completionHandler:^(NSError *error) {
if (error) {
NSLog(#"Error: %#", error);
}
}];
NSLog(#"Successfully ended turn");
}
When I try retrieving the match data, I tried this.
[match loadMatchDataWithCompletionHandler:^(NSData *matchData, NSError *error) {
if (matchData)
{
RaceGame *updatedGame = [NSKeyedUnarchiver unarchiveObjectWithData:matchData];
NSLog(#"Match Data: %#", updatedGame.status); //prints null
callback(matchData);
}
}];
However, status is null. I've checked that match isn't null either. I also printed out the match and it said that matchData.length = 135, but I kept changing things around and it was still 135 so I'm not sure if that's helpful.
Any ideas on why status isn't changing?
--EDIT--
.m
#implementation RaceGame
#synthesize status;
#pragma mark - NSCoding protocol
- (void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:status forKey:#"status"];
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super init]) {
self.status = [aDecoder decodeObjectForKey:#"status"];
}
return self;
}
#end
.h
#interface RaceGame : NSObject <NSCoding> {
NSString *status;
}
/* Match Data */
#property (nonatomic, copy) NSString *status;
#end
Never mind, really stupid mistake by me. I was testing it on two devices and I only ran the updated version on one of the devices.
I have a problem with an singleton pattern.
I have read the following tutorials about singleton classes and have created my own.
http://www.galloway.me.uk/utorials/singleton-classes/
http://www.johnwordsworth.com/2010/04/iphone-code-snippet-the-singleton-pattern/
The first time i build & run the app it works like it should. No problems at all!
But when i rebuild the app the singleton class does not work properly anymore. The first init works like it should but when i call it again after a button click it crashes my app.
My singleton class:
BPManager.h
#interface BPManager : NSObject {
NSString *dbPath;
}
#property (nonatomic, retain) NSString *dbPath;
+ (id)bpManager;
- (void)initDatabase:(NSString *)dbName;
- (int)getQuestions;
#end
BPManager.m
static BPManager *sharedMyManager = nil;
#implementation BPManager
#synthesize dbPath;
- (void)initDatabase:(NSString *)dbName
{
dbPath = dbName;
}
-(int)getQuestions
{
NSLog(#"getQuestions");
}
- (id)init {
if ((self = [super init])) {
}
return self;
}
+ (BPManager *) bpManager {
#synchronized(self) {
if(sharedMyManager != nil) return sharedMyManager;
static dispatch_once_t pred; // Lock
dispatch_once(&pred, ^{ // This code is called at most once per app
sharedMyManager = [[BPManager alloc] init];
});
}
return sharedMyManager;
}
- (void)dealloc {
[dbPath release];
[super dealloc];
}
When i call the following code when building my interface, the app creates the singleton:
BPManager *manager = [BPManager bpManager];
[manager initDatabase:#"database.db"];
Note: At this point i can create references to the class from other files as well. But when i click on a button it seems to loose his references.
But when a button is clicked, the following code is ecexuted:
BPManager *manager = [BPManager bpManager];
int count = [manager getQuestions];
The app should get the sharedInstance. That works, only the parameters (like dbPath) are not accessible. Why is that?
Edit:
after some research, i have changed the method to:
+ (BPManager *) bpManager {
#synchronized(self) {
if(sharedMyManager != nil) return sharedMyManager;
static dispatch_once_t pred; // Lock
dispatch_once(&pred, ^{ // This code is called at most once per app
sharedMyManager = [[BPManager alloc] init];
});
}
return sharedMyManager;
}
But the problem is not solved
How about
#interface BPManager : NSObject
#property (nonatomic, copy) NSString *dbName;
#property (nonatomic, assign) int questions;
-(id) initWithDBName:(NSString*) dbName {
#end
#import "BPManager.h"
#implementation BPManager
#synthesize dbName=_dbName, questions;
+(BPManager *)singleton {
static dispatch_once_t pred;
static BPManager *shared = nil;
dispatch_once(&pred, ^{
shared = [[BPManager alloc] initWithDBName:#"database.db"];
});
return shared;
}
-(id) initWithDBName:(NSString*) dbName {
self = [super init]
if (self) self.dbName = dbName;
return self;
}
-(void)dealloc {
[_dbName release];
[super dealloc];
}
#end
BPManager *manager = [BPManager singleton];
int count = [manager questions];
The static is private to the implementation file but no reason it should be even accessible outside the singleton method. The init overrides the default implementation with the default implementation so it's useless. In Objective-C you name the getter with the var name (count), not getCount. Initializing a class twice causes an undefined behaviour. No need to synchronize or check for if==nil when you are already using dispatch_once, see Care and Feeding of Singletons. NSString should always use copy instead retain in #property. You don't need the dealloc because this is going to be active forever while your app is running, but it's just there in case you want to use this class as a non singleton . And you probably are as good with this class being an ivar in your delegate instead a singleton, but you can have it both ways.
I'm not sure whether it's the (complete) answer, but one major flaw is that you're using instance variables (self, super) in a class method, +(id)bpManager; I'm actually surprised it let you compile that at all. Change the #synchronized(self) to #synchronized(sharedMyManager), and the [[super alloc...] init] to [[BPManager alloc...] init]. And, writing that just made me realize that the problem looks like accessing a subclassed method on an object instantiated as the superclass, but that should have been overwritten in the dispatch. Shouldn't you really only need one of those anyway, why double-init like that? (And while we're there, that's a memory leak - init'd in the if() and then overwritten in the closure without releasing it.)
The solution of Jano must work well. I use this way too to create singleton object. And I don't have any problem.
For your code, I think that if you use #synchronized (it's not necessary cause your have dispatch_once_t as Jano said), you should not call return in #synchronized.
+ (BPManager *) bpManager {
#synchronized(self) {
if(sharedMyManager == nil) {
static dispatch_once_t pred; // Lock
dispatch_once(&pred, ^{ // This code is called at most once per app
sharedMyManager = [[BPManager alloc] init];
});
}
}
return sharedMyManager;
}