Added -subscribeState:usingBlock:

Author: kevin-lyn

STNetTaskQueue/STNetTask.h

@@ -23,6 +23,7 @@ FOUNDATION_EXPORT NSString *const STNetTaskUnknownError;
     }]; \
     return nil; \
 }]
+
 #endif
 
 @class STNetTask;
@@ -39,6 +40,14 @@ FOUNDATION_EXPORT NSString *const STNetTaskUnknownError;
 
 @end
 
+typedef NS_ENUM(NSUInteger, STNetTaskState) {
+    STNetTaskStateCancalled,
+    STNetTaskStateFinished,
+    STNetTaskStateRetrying
+};
+
+typedef void (^STNetTaskSubscriptionBlock)(STNetTask *task);
+
 @interface STNetTask : NSObject
 
 /* Error object which contains error message when net task is failed. */
@@ -71,18 +80,21 @@ FOUNDATION_EXPORT NSString *const STNetTaskUnknownError;
 
 /*
  A callback method which is called when the net task is finished successfully.
+ Note: this method will be called in thread of STNetTaskQueue.
  
  @param response id The response object.
  */
 - (void)didResponse:(id)response;
 
 /*
  A callback method which is called when the net task is failed.
+ Note: this method will be called in thread of STNetTaskQueue.
  */
 - (void)didFail;
 
 /*
  A callback method which is called when the net task is retried.
+ Note: this method will be called in thread of STNetTaskQueue.
  */
 - (void)didRetry;
 
@@ -110,4 +122,13 @@ FOUNDATION_EXPORT NSString *const STNetTaskUnknownError;
  */
 - (NSTimeInterval)retryInterval;
 
+/*
+ Subscribe state of net task by using block
+ 
+ @param state STNetTaskState state of net task
+ @param block STNetTaskSubscriptionBlock block is called when net task is in subscribed state.
+        NOTE: this block will be called in main thread.
+ */
+- (void)subscribeState:(STNetTaskState)state usingBlock:(STNetTaskSubscriptionBlock)block;
+
 @end

STNetTaskQueue/STNetTask.m

@@ -16,6 +16,7 @@ @interface STNetTask ()
 @property (atomic, assign) BOOL cancelled;
 @property (atomic, assign) BOOL finished;
 @property (atomic, assign) NSUInteger retryCount;
+@property (nonatomic, strong) NSMutableDictionary *stateToBlock;
 
 @end
 
@@ -56,4 +57,33 @@ - (NSTimeInterval)retryInterval
     return 0;
 }
 
+- (void)subscribeState:(STNetTaskState)state usingBlock:(STNetTaskSubscriptionBlock)block
+{
+    if (!self.stateToBlock) {
+        self.stateToBlock = [NSMutableDictionary new];
+    }
+    NSAssert(self.stateToBlock[@(state)] == nil, @"State is subscribed already");
+    self.stateToBlock[@(state)] = [block copy];
+}
+
+- (void)notifyState:(STNetTaskState)state
+{
+    dispatch_async(dispatch_get_main_queue(), ^{
+        STNetTaskSubscriptionBlock block = self.stateToBlock[@(state)];
+        if (block) {
+            block(self);
+        }
+        
+        switch (state) {
+            case STNetTaskStateFinished:
+            case STNetTaskStateCancalled: {
+                self.stateToBlock = nil;
+            }
+                break;
+            default:
+                break;
+        }
+    });
+}
+
 @end

STNetTaskQueue/STNetTaskQueue.m

@@ -16,6 +16,8 @@ @interface STNetTask (STInternal)
 @property (atomic, assign) BOOL finished;
 @property (atomic, assign) NSUInteger retryCount;
 
+- (void)notifyState:(STNetTaskState)state;
+
 @end
 
 @interface STNetTaskQueue()
@@ -120,6 +122,7 @@ - (void)_cancelTask:(STNetTask *)task
 
     [self.handler netTaskQueue:self didCancelTask:task];
     task.cancelled = YES;
+    [task notifyState:STNetTaskStateCancalled];
 }
 
 - (BOOL)_retryTask:(STNetTask *)task withError:(NSError *)error
@@ -136,6 +139,7 @@ - (void)_retryTask:(STNetTask *)task
 {
     if (!task.cancelled) {
         [task didRetry];
+        [task notifyState:STNetTaskStateRetrying];
         [self addTask:task];
     }
 }
@@ -183,6 +187,7 @@ - (void)_task:(STNetTask *)task didResponse:(id)response
 
     task.pending = NO;
     task.finished = YES;
+    [task notifyState:STNetTaskStateFinished];
 
     [self _netTaskDidEnd:task];
 
@@ -213,6 +218,7 @@ - (void)_task:(STNetTask *)task didFailWithError:(NSError *)error
     [task didFail];
     task.pending = NO;
     task.finished = YES;
+    [task notifyState:STNetTaskStateFinished];
 
     [self _netTaskDidEnd:task];
 

STNetTaskQueueTest/STNetTaskQueueTest/STNetTaskQueueTestHTTP.m

@@ -185,6 +185,28 @@ - (void)testTaskDelegateForClass
     [self waitForExpectationsWithTimeout:10 handler:nil];
 }
 
+- (void)testSubscriptionBlock
+{
+    [self setUpNetTaskQueueWithBaseURLString:@"http://jsonplaceholder.typicode.com"];
+    
+    _expectation = [self expectationWithDescription:@"testSubscriptionBlock"];
+    
+    STTestGetNetTask *testGetTask = [STTestGetNetTask new];
+    testGetTask.id = 1;
+    [[STNetTaskQueue sharedQueue] addTask:testGetTask];
+    
+    [testGetTask subscribeState:STNetTaskStateFinished usingBlock:^(STNetTask *task) {
+        if (task.finished) {
+            [_expectation fulfill];
+        }
+        else {
+            XCTFail(@"%@ failed", _expectation.description);
+        }
+    }];
+    
+    [self waitForExpectationsWithTimeout:10 handler:nil];
+}
+
 - (void)netTaskDidEnd:(STNetTask *)task
 {
     if (!_expectation) {