Top "Objective-c-blocks" questions

How to simplify callback logic with a Block?

Let's say I need to communicate with a class that provides a protocol and calls delegate methods when an operation …

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Simple GCD Serial Queue example like FIFO using blocks

I read Apple documentation on how to Use serial queues to ensure that tasks to execute in a predictable order …

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How to remove elements in NSMutableArray or NSMutableDictionary during enumeration?

I am using block based enumeration similar to the following code: [[[rows objectForKey:self.company.coaTypeCode] objectForKey:statementType] enumerateObjectsWithOptions:NSEnumerationConcurrent …

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Grand Central Dispatch (GCD) with CoreData

I'm using Grand Central Dispatch (GCD) in my application to do some heavy lifting. The application is using Core-Data for …

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How can I retrieve a return value from a completion block?

Is it possible to run a completion block on the main thread? For example, I have one method which returns …

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Why do nil / NULL blocks cause bus errors when run?

I started using blocks a lot and soon noticed that nil blocks cause bus errors: typedef void (^SimpleBlock)(void); SimpleBlock …

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How to call method on presenting view controller from modal view controller

I have a modal view controller that I called in from another view controller. Upon dismissal of the modal view …

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Copying blocks (ie: copying them to instance variables) in Objective-C

I'm trying to understand blocks. I get how to use them normally, when passed directly to a method. I'm interested …

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Is it necessary to use weak references to self always inside blocks..?

I am getting confused with use of self inside blocks, I go through some of Apple's documents but still cannot …

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Should I still copy/Block_copy the blocks under ARC?

I've just stumbled over the following SO topic: Why should we copy blocks rather than retain? which has the following …

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