nsoperation

I need in my application to download directories and their content. So I decided to implement a NSOperationQueue and I subclassed NSOperation to implement NSURLRequest etc... The problem is I add all the operations at once and I can't figure out when all the files for one directory are downloaded in order to update the UI and enable this specific directory. Now I have to wait that all the files from all the directories are downloaded in order to update the UI. I already implemented key-value observing for the operationCount of the NSOperationQueue and the isFinished of the NSOperation but I

I'm fetching some data from Facebook Connect (using the FBConnect Objective-C 2.0 framework) and I'm doing all that in an NSOperation. It is in an NSOperation because I have several other operations that run as well and this is one of them. The problem is that all the FBConnect calls are asynchronous. Because of this, the main method of the NSOperation quickly finishes and the operation is marked as completed. Is there some way to overcome this? It would appear there are no synchronous options in FBConnect! Many thanks, Mike Below is a full example. In your subclass, after your async method

This question already has an answer here: NSOperation vs Grand Central Dispatch 8 answers Which tasks would be better suited to using NSOperation as opposed to using GCD when programming for the iPhone? To me they seem to do the same thing. I can't see the strengths and weaknesses one has over the other. NSOperation is built on top of GCD, so the question is more about whether you use NSOperation or pass a block directly to GCD. An NSOperation is bulky and needs more boiler-plate codes to set it up, but it has a lot more functionality. You can create the same NSOperation subclass in various

As the title suggests, what is the default value of the maxConcurrentOperationCount for NSOperationQueue? Is it set to a value of 1? From the documentation , The maximum number of concurrent operations set explicitly on the receiver using the setMaxConcurrentOperationCount: method. If no value has been explicitly set, this method returns NSOperationQueueDefaultMaxConcurrentOperationCount by default . So it is NSOperationQueueDefaultMaxConcurrentOperationCount . If this is set, it will choose an appropriate value based on the number of available processors and other relevant factors. This is

Update 2: I found a workaround which is to synchronize MOC deallocating and saving. Please see the updated project. https://github.com/shuningzhou/MOCDeadLock.git Note: I made it fail more aggressively. Don't run it on a real device! Update: A sample project to demonstrate this issue. https://github.com/shuningzhou/MOCDeadLock.git XCode 6.2: Unable to reproduce. XCode 6.3: Reproducible. XCode 6.4 beta: Reproducible. ========================== The Issue =============================== Our app randomly stuck on OSSpinLockLockSlow after upgrading to XCode 6.3. In our project, we used NSOperation

I have a UICollectionView , but the same methods should apply to UITableViews . Each of my cells contains an image I load from disk, which is a slow operation. To mitigate this, I use an async dispatch queue. This works fine, but quickly scrolling results in these operations stacking up, such that the cell will change its image from one to another in sequence, until finally stopping at the last call. In the past, I've done a check to see if the cell was still visible, and if not I don't continue. However, this is not working with UICollectionView, and anyway it is not efficient. I am

I want to do NSURLConnection in background mode,because it response is having much data.Forums are telling to use Apple's finite length coding to use in didEnterBackground . but I want to avoid it.instead of it I use following code through NSOperation with NSInvocation as, but it is not working. connectToServer is having NSURLConnection operation.any help please? didReceiveData , didReceiveResponse delegate methods are not called? NSOperationQueue *queue = [NSOperationQueue new]; NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector