Adjust completion block implementation for RKPaginator to enable completion block to be invoked when used without a strong reference. fixes #1119 fixes #1093

Code/Network/RKObjectRequestOperation.m

@@ -201,6 +201,20 @@ static NSString *RKStringDescribingURLResponseWithData(NSURLResponse *response,
     }
 }
 
+- (void)setWillMapDeserializedResponseBlock:(id (^)(id))block
+{
+    if (!block) {
+        _willMapDeserializedResponseBlock = nil;
+    } else {
+        __unsafe_unretained id weakSelf = self;
+        _willMapDeserializedResponseBlock = ^id (id deserializedResponse) {
+            id result = block(deserializedResponse);
+            [weakSelf setWillMapDeserializedResponseBlock:nil];
+            return result;
+        };
+    }
+}
+
 - (void)setCompletionBlockWithSuccess:(void (^)(RKObjectRequestOperation *operation, RKMappingResult *mappingResult))success
                               failure:(void (^)(RKObjectRequestOperation *operation, NSError *error))failure
 {

Code/Network/RKPaginator.m

@@ -178,20 +178,21 @@ static NSUInteger RKPaginatorDefaultPerPage = 25;
     
     // Add KVO to ensure notification of loaded state prior to execution of completion block
     [self.objectRequestOperation addObserver:self forKeyPath:@"isFinished" options:0 context:nil];
-    
-    __weak RKPaginator *weakSelf = self;
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-retain-cycles"
     [self.objectRequestOperation setWillMapDeserializedResponseBlock:^id(id deserializedResponseBody) {
         NSError *error = nil;
-        RKMappingOperation *mappingOperation = [[RKMappingOperation alloc] initWithSourceObject:deserializedResponseBody destinationObject:weakSelf mapping:weakSelf.paginationMapping];
+        RKMappingOperation *mappingOperation = [[RKMappingOperation alloc] initWithSourceObject:deserializedResponseBody destinationObject:self mapping:self.paginationMapping];
         BOOL success = [mappingOperation performMapping:&error];
         if (!success) {
-            weakSelf.pageCount = 0;
-            weakSelf.currentPage = 0;
+            self.pageCount = 0;
+            self.currentPage = 0;
             RKLogError(@"Paginator didn't map info to compute page count. Assuming no pages.");
-        } else if (weakSelf.perPage && [weakSelf hasObjectCount]) {
-            float objectCountFloat = weakSelf.objectCount;
-            weakSelf.pageCount = ceilf(objectCountFloat / weakSelf.perPage);
-            RKLogInfo(@"Paginator objectCount: %ld pageCount: %ld", (long)weakSelf.objectCount, (long)weakSelf.pageCount);
+        } else if (self.perPage && [self hasObjectCount]) {
+            float objectCountFloat = self.objectCount;
+            self.pageCount = ceilf(objectCountFloat / self.perPage);
+            RKLogInfo(@"Paginator objectCount: %ld pageCount: %ld", (long)self.objectCount, (long)self.pageCount);
         } else {
             RKLogError(@"Paginator perPage set is 0.");
         }
@@ -199,14 +200,15 @@ static NSUInteger RKPaginatorDefaultPerPage = 25;
         return deserializedResponseBody;
     }];
     [self.objectRequestOperation setCompletionBlockWithSuccess:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
-        if (weakSelf.successBlock) {
-            weakSelf.successBlock(weakSelf, [mappingResult array], weakSelf.currentPage);
+        if (self.successBlock) {
+            self.successBlock(self, [mappingResult array], self.currentPage);
         }
     } failure:^(RKObjectRequestOperation *operation, NSError *error) {
-        if (weakSelf.failureBlock) {
-            weakSelf.failureBlock(weakSelf, error);
+        if (self.failureBlock) {
+            self.failureBlock(self, error);
         }
     }];
+#pragma clang diagnostic pop
     
     if (self.operationQueue) {
         [self.operationQueue addOperation:self.objectRequestOperation];

Tests/Logic/ObjectMapping/RKPaginatorTest.m

@@ -220,9 +220,7 @@ static NSString * const RKPaginatorTestResourcePathPattern = @"/paginate?per_pag
     } failure:nil];
     [paginator loadPage:1];
     [paginator waitUntilFinished];
-    dispatch_async(dispatch_get_main_queue(), ^{
-        expect(blockObjects).notTo.beNil();
-    });
+    expect(blockObjects).willNot.beNil();
 }
 
 - (void)testOnDidFailWithErrorBlockIsInvokedOnError
@@ -235,9 +233,19 @@ static NSString * const RKPaginatorTestResourcePathPattern = @"/paginate?per_pag
     }];
     [paginator loadPage:999];
     [paginator waitUntilFinished];
-    dispatch_async(dispatch_get_main_queue(), ^{
-        expect(expectedError).notTo.beNil();
-    });
+    expect(expectedError).willNot.beNil();
+}
+
+- (void)testInvocationOfCompletionBlockWithoutWaiting
+{
+    NSURLRequest *request = [NSURLRequest requestWithURL:self.paginationURL];
+    RKPaginator *paginator = [[RKPaginator alloc] initWithRequest:request paginationMapping:self.paginationMapping responseDescriptors:@[ self.responseDescriptor ]];
+    __block NSArray *blockObjects = nil;
+    [paginator setCompletionBlockWithSuccess:^(RKPaginator *paginator, NSArray *objects, NSUInteger page) {
+        blockObjects = objects;
+    } failure:nil];
+    [paginator loadPage:1];
+    expect(blockObjects).willNot.beNil();
 }
 
 - (void)testLoadingNextPageOfObjects