How to use BlockOperation in swift?

In Swift, BlockOperation is a subclass of Operation that allows you to encapsulate the code you want to execute concurrently. You can use it to create operations that consist of one or more blocks of code. Here’s an example of how to use BlockOperation:

import Foundation

// Create a BlockOperation
let blockOperation = BlockOperation {
    // Code to be executed concurrently
    print("BlockOperation: Task 1")
}

// Add additional blocks to the operation
blockOperation.addExecutionBlock {
    print("BlockOperation: Task 2")
}

blockOperation.addExecutionBlock {
    print("BlockOperation: Task 3")
}

// Create a completion block (optional)
blockOperation.completionBlock = {
    print("BlockOperation: All tasks completed")
}

// Create an OperationQueue
let operationQueue = OperationQueue()

// Add the BlockOperation to the queue
operationQueue.addOperation(blockOperation)

In this example:

1. We create a BlockOperation instance and add one or more blocks of code using addExecutionBlock.
2. Optionally, we set a completion block using completionBlock to be executed when all the tasks in the operation are completed.
3. We create an OperationQueue to manage the execution of operations.
4. We add the BlockOperation to the operation queue using addOperation.

The OperationQueue takes care of managing the concurrent execution of operations. Keep in mind that BlockOperation is suitable for relatively simple concurrent tasks. If you need more control or coordination between multiple operations, you might consider using Operation directly or implementing a custom subclass.

Here’s a more advanced example that shows how to use dependencies between operations:

import Foundation

let operationQueue = OperationQueue()

let operation1 = BlockOperation {
    print("Operation 1")
}

let operation2 = BlockOperation {
    print("Operation 2")
}

let operation3 = BlockOperation {
    print("Operation 3")
}

// Set dependencies between operations
operation2.addDependency(operation1)
operation3.addDependency(operation2)

// Add operations to the queue
operationQueue.addOperations([operation1, operation2, operation3], waitUntilFinished: false)

In this example, operation2 depends on the completion of operation1, and operation3 depends on the completion of operation2. The OperationQueue will automatically ensure that the operations are executed in the correct order.