Implement thread-safe state changes in BUYOperation. Refactor BUYClient.

Mobile Buy SDK/Mobile Buy SDK/Data/BUYClient.h

@@ -96,7 +96,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  *  Queue where on which all request operation are executed
  */
-@property (nonatomic, strong, nonnull) NSOperationQueue *requestQueue;
+@property (nonatomic, strong, readonly, nonnull) NSOperationQueue *requestQueue;
 
 /**
  *  Queue where callbacks will be called

Mobile Buy SDK/Mobile Buy SDK/Data/BUYClient.m

@@ -32,12 +32,7 @@ static NSString * const BUYClientJSONMimeType = @"application/json";
 
 @interface BUYClient () <NSURLSessionDelegate>
 
-@property (nonatomic, strong) NSString *shopDomain;
-@property (nonatomic, strong) NSString *apiKey;
-@property (nonatomic, strong) NSString *appId;
-
 @property (nonatomic, strong) NSURLSession *session;
-@property (nonatomic, strong) NSString *merchantId;
 
 @end
 
@@ -58,15 +53,15 @@ static NSString * const BUYClientJSONMimeType = @"application/json";
 	
 	self = [super init];
 	if (self) {
-		self.modelManager = [BUYModelManager modelManager];
-		self.shopDomain = shopDomain;
-		self.apiKey = apiKey;
-		self.appId = appId;
-		self.applicationName = [[NSBundle mainBundle] infoDictionary][@"CFBundleName"] ?: @"";
-		self.queue = dispatch_get_main_queue();
-		self.requestQueue = [NSOperationQueue new];
-		self.session = [self urlSession];
-		self.pageSize = 25;
+		_modelManager = [BUYModelManager modelManager];
+		_shopDomain = shopDomain;
+		_apiKey = apiKey;
+		_appId = appId;
+		_applicationName = [[NSBundle mainBundle] infoDictionary][@"CFBundleName"] ?: @"";
+		_queue = dispatch_get_main_queue();
+		_requestQueue = [NSOperationQueue new];
+		_session = [self urlSession];
+		_pageSize = 25;
 	}
 	return self;
 }
@@ -219,7 +214,7 @@ static NSString * const BUYClientJSONMimeType = @"application/json";
 
 - (void)enableApplePayWithMerchantId:(NSString *)merchantId
 {
-	self.merchantId = merchantId;
+	_merchantId = merchantId;
 }
 
 @end

Mobile Buy SDK/Mobile Buy SDK/Operations/BUYOperation.h

@@ -10,4 +10,7 @@
 
 @interface BUYOperation : NSOperation
 
+- (void)startExecution;
+- (void)finishExecution;
+
 @end

Mobile Buy SDK/Mobile Buy SDK/Operations/BUYOperation.m

@@ -8,10 +8,15 @@
 
 #import "BUYOperation.h"
 
+typedef NS_ENUM(NSUInteger, BUYOperationState) {
+	BUYOperationStateExecuting = 1,
+	BUYOperationStateFinished  = 2,
+};
+
 @interface BUYOperation ()
 
-@property (atomic, assign) BOOL isExecuting;
-@property (atomic, assign) BOOL isFinished;
+@property (nonatomic, assign) BUYOperationState state;
+@property (nonatomic, strong) NSLock *lock;
 
 @end
 
@@ -23,25 +28,90 @@
 {
 	self = [super init];
 	if (self) {
-		
+		_lock = [NSLock new];
 	}
 	return self;
 }
 
+#pragma mark - Concurrent -
+- (BOOL)isAsynchronous
+{
+	return YES;
+}
+
+- (BOOL)isConcurrent
+{
+	return YES;
+}
+
+#pragma mark - Accessors -
+- (BOOL)isExecuting
+{
+	return self.state == BUYOperationStateExecuting;
+}
+
+- (BOOL)isFinished
+{
+	return self.state == BUYOperationStateFinished;
+}
+
 #pragma mark - Setters -
 
-- (void)setExecuting:(BOOL)executing
+- (void)setState:(BUYOperationState)state
 {
-	[self willChangeValueForKey:@"isExecuting"];
-	self.isExecuting = executing;
-	[self didChangeValueForKey:@"isExecuting"];
+	[self.lock lock];
+	
+	NSString *oldPath = BUYOperationStateKeyPath(self.state);
+	NSString *newPath = BUYOperationStateKeyPath(state);
+	
+	/* ----------------------------------
+	 * We avoid changing state if the new
+	 * state is the same or the operation
+	 * has been cancelled.
+	 */
+	if ([oldPath isEqualToString:newPath] || self.isCancelled) {
+		[self.lock unlock];
+		return;
+	}
+	
+	[self willChangeValueForKey:newPath];
+	[self willChangeValueForKey:oldPath];
+	_state = state;
+	NSLog(@"Setting state");
+	[self didChangeValueForKey:oldPath];
+	[self didChangeValueForKey:newPath];
+	
+	[self.lock unlock];
+}
+
+#pragma mark - Start -
+- (void)start
+{
+	[self startExecution];
+}
+
+#pragma mark - Execution -
+- (void)startExecution
+{
+	self.state = BUYOperationStateExecuting;
+	NSLog(@"Started operation");
+}
+
+- (void)finishExecution
+{
+	self.state = BUYOperationStateFinished;
+	NSLog(@"Finished operation");
 }
 
-- (void)setFinished:(BOOL)finished
+#pragma mark - State -
+
+static inline NSString * BUYOperationStateKeyPath(BUYOperationState state)
 {
-	[self willChangeValueForKey:@"isFinished"];
-	self.isFinished = finished;
-	[self didChangeValueForKey:@"isFinished"];
+	switch (state) {
+		case BUYOperationStateFinished:  return @"isFinished";
+		case BUYOperationStateExecuting: return @"isExecuting";
+	}
+	return @"";
 }
 
 @end

Mobile Buy SDK/Mobile Buy SDK/Operations/BUYRequestOperation.h

@@ -11,14 +11,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @protocol BUYSerializable;
 
-typedef NS_ENUM(NSUInteger, BUYRequestMethod) {
-	BUYRequestMethodGET,
-	BUYRequestMethodPOST,
-	BUYRequestMethodPUT,
-	BUYRequestMethodPATCH,
-	BUYRequestMethodDELETE,
-};
-
 typedef void (^BUYRequestOperationCompletion)(NSDictionary * _Nullable json, NSURLResponse * _Nullable response, NSError * _Nullable error);
 
 @interface BUYRequestOperation : BUYOperation
@@ -26,6 +18,8 @@ typedef void (^BUYRequestOperationCompletion)(NSDictionary * _Nullable json, NSU
 @property (strong, nonatomic, readonly, nonnull) NSURLSession *session;
 @property (strong, nonatomic, readonly, nonnull) NSURLRequest *originalRequest;
 
++ (instancetype)operationWithSession:(NSURLSession *)session request:(NSURLRequest *)request payload:(id<BUYSerializable> _Nullable)payload completion:(BUYRequestOperationCompletion)completion;
+
 - (instancetype)initWithSession:(NSURLSession *)session request:(NSURLRequest *)request payload:(id<BUYSerializable> _Nullable)payload completion:(BUYRequestOperationCompletion)completion;
 
 @end

Mobile Buy SDK/Mobile Buy SDK/Operations/BUYRequestOperation.m

@@ -44,6 +44,9 @@ NSString * const kShopifyError = @"shopify";
 @implementation BUYRequestOperation
 
 #pragma mark - Init -
++ (instancetype)operationWithSession:(NSURLSession *)session request:(NSURLRequest *)request payload:(id<BUYSerializable>)payload completion:(BUYRequestOperationCompletion)completion {
+	return [[[self class] alloc] initWithSession:session request:request payload:payload completion:completion];
+}
 
 - (instancetype)initWithSession:(NSURLSession *)session request:(NSURLRequest *)request payload:(id<BUYSerializable>)payload completion:(BUYRequestOperationCompletion)completion
 {
@@ -60,34 +63,32 @@ NSString * const kShopifyError = @"shopify";
 
 - (void)finishWithJSON:(id)JSON response:(NSHTTPURLResponse *)response
 {
-	[self setExecuting:NO];
+	[self finishExecution];
 	self.completion(JSON, response, nil);
 }
 
 - (void)finishWithError:(NSError *)error response:(NSHTTPURLResponse *)response
 {
-	[self setExecuting:NO];
+	[self finishExecution];
 	self.completion(nil, response, error);
 }
 
 - (void)finishByCancellation
 {
-	[self setFinished:YES];
-	[self setExecuting:NO];
+	[self finishExecution];
 }
 
 #pragma mark - Start -
 
-- (void)start
+- (void)startExecution
 {
-	[super start];
-	
 	if (self.isCancelled) {
 		[self finishByCancellation];
 		return;
 	}
 	
-	[self setExecuting:YES];
+	[super startExecution];
+	
 	NSURLSessionDataTask *task = [self.session dataTaskWithRequest:self.originalRequest completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
 		
 		if (self.isCancelled) {
@@ -114,17 +115,4 @@ NSString * const kShopifyError = @"shopify";
 	[task resume];
 }
 
-#pragma mark - BUYRequestMethod -
-
-//static inline NSString * BUYRequestMethodString(BUYRequestMethod method)
-//{
-//	switch (method) {
-//		case BUYRequestMethodGET:    return @"GET";
-//		case BUYRequestMethodPOST:   return @"POST";
-//		case BUYRequestMethodPATCH:  return @"PATCH";
-//		case BUYRequestMethodPUT:    return @"PUT";
-//		case BUYRequestMethodDELETE: return @"DELETE";
-//	}
-//}
-
 @end