RESTKit 0.20 Operations queue - restkit-0.20

Question

I am trying to implement RESTKit 0.20 operations queue, I have read on the blogs that NSOperationQueue may also be used to create queue of operations. I wants to use native approach of RestKit operations queue.
Can any one please post the piece of code/example with followings:
How to use Operations queue in RestKit.
Setting queue to execute one operation at a time.
If the first operation is not completed then I need to cancel pending operations in this queue.
Looks forward to hear form you.
Thanks.

Answer 1

Here I am sharing you piece of Code I am using for ManagedObjects(CoreData Objects) Request Operations.
Get references to objectManager & managedObjectContext;
RKObjectManager *objectManager = [(AppDelegate *)[[UIApplication sharedApplication] delegate] objectManager];
NSManagedObjectContext *managedObjectContext = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
Initialise array to hold up operations in it
NSMutableArray *requestOperations = [NSMutableArray array];
Prepare first Operation and add it to requestOperations array, notice failure block is cancelling pending operations in queue.
// Setup Organization Operation
//
NSString *url = #"organizations/syncAll/";
NSMutableURLRequest *organizationsRequest = [objectManager requestWithObject:organizations method:RKRequestMethodPOST path:url parameters:nil];
RKObjectRequestOperation *organizationsOperation = [objectManager managedObjectRequestOperationWithRequest:organizationsRequest managedObjectContext:managedObjectContext success: ^(RKObjectRequestOperation *operation, RKMappingResult *result) {
..
[RKUtils isHandleStatusError:[result array]];
} failure: ^(RKObjectRequestOperation *operation, NSError *error) {
NSLog(#"Failed with error: %#", [error localizedDescription]);
[objectManager cancelAllObjectRequestOperationsWithMethod:RKRequestMethodPOST matchingPathPattern:#"games/getNotStartedGames"];
[RKUtils handleError:error];
}];
[requestOperations addObject:organizationsOperation];
prepare second operation
// Setup Games Operation
//
url = #"games/syncAll/";
NSMutableURLRequest *gamesRequest = [objectManager requestWithObject:games method:RKRequestMethodPOST path:url parameters:nil];
RKObjectRequestOperation *gamesOperation = [objectManager managedObjectRequestOperationWithRequest:gamesRequest managedObjectContext:managedObjectContext success: ^(RKObjectRequestOperation *operation, RKMappingResult *result) {
..
[RKUtils isHandleStatusError:[result array]];
} failure: ^(RKObjectRequestOperation *operation, NSError *error) {
NSLog(#"Failed with error: %#", [error localizedDescription]);
if (error.code == NSURLErrorCancelled) {
return;
}
[RKUtils handleError:error];
}];
[requestOperations addObject:gamesOperation];
prepare more operations
..
Set max concurrent operations count to 1
objectManager.operationQueue.maxConcurrentOperationCount = 1;
Enqueue all operations in queue. The queue will start executing operations one by one.
// Enqueue Request Operations
[objectManager enqueueBatchOfObjectRequestOperations:requestOperations progress: ^(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations) {
NSLog(#"totalNumberOfOperations : %d", totalNumberOfOperations);
NSLog(#"numberOfFinishedOperations : %d", numberOfFinishedOperations);
} completion: ^(NSArray *operations) {
NSLog(#"completion");
}];
Hope that gonna deliver your purpose.
Cheers,