adlai-holler / coredataoperation

A fast, safe, flexible operation class for updating data stored in Core Data, written in Swift.

CoreDataOperation

CoreDataOperation is a fast, safe, flexible operation for updating your core data models. It supports the latest Swift 2.1 syntax, and does all its work in a background managed object context.

Installation

• Using CocoaPods by adding pod CoreDataOperation to your Podfile
• Using Carthage by adding github "Adlai-Holler/CoreDataOperation" to your Cartfile.

How to Use

let likeOperation = CoreDataOperation<Int>(targetContext: myContext, saveDepth: .ToPersistentStore) { context in
    guard let post = Post.withID(postID, inContext: context) else {
        throw Error.PostWasDeleted
    }
    if post.doILike {
        post.doILike = false
        post.likeCount -= 1
    } else {
        post.doILike = true
        post.likeCount += 1
    }
    post.updatedAt = NSDate()
    return post.likeCount
}
likeOperation.setCompletionBlockWithSuccess( { likeOperation, likeCount in
    // Switch to main queue to update UI
    dispatch_async(dispatch_get_main_queue()) {
        likeCountLabel.text = String(likeCount)
    }
}, failure: { likeOperation, error in
    dispatch_async(dispatch_get_main_queue()) {
        // Show an error.
    }
})
myOperationQueue.addOperation(likeOperation)

Features

• Safe. All operations are confined to a private, background context, so if you get into a bad state, none of your working contexts will be affected.
• Fully asynchronous. No threads are blocked, no two contexts are locked at the same time, and no context is locked for any longer than it absolutely must be.
• Cancelable. The operation checks if it is canceled after each step.
• Modern Swift syntax. Your operation block can throw an error, and it can return a value of any type which can be accessed after the operation is over.
• Lightweight. The body block is disposed of after executing, and the target managed object context is not retained.
• Tests! CoreDataOperation is tested like crazy.