Add convenience initializers for block based operations

2 files changed, 61 insertions, 3 deletions

diff --git a/ios/MullvadVPN/Operations/AsyncBlockOperation.swift b/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
index a0096f77d6..9c4101fdff 100644
--- a/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
+++ b/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
@@ -13,16 +13,32 @@ class AsyncBlockOperation: AsyncOperation {
     private var executionBlock: ((AsyncBlockOperation) -> Void)?
     private var cancellationBlocks: [() -> Void] = []
 
-    init(dispatchQueue: DispatchQueue?, block: @escaping (AsyncBlockOperation) -> Void) {
+    override init(dispatchQueue: DispatchQueue? = nil) {
+        super.init(dispatchQueue: dispatchQueue)
+    }
+
+    init(dispatchQueue: DispatchQueue? = nil, block: @escaping (AsyncBlockOperation) -> Void) {
         executionBlock = block
         super.init(dispatchQueue: dispatchQueue)
     }
 
+    init(dispatchQueue: DispatchQueue? = nil, block: @escaping () -> Void) {
+        executionBlock = { operation in
+            block()
+            operation.finish()
+        }
+        super.init(dispatchQueue: dispatchQueue)
+    }
+
     override func main() {
         let block = executionBlock
         executionBlock = nil
 
-        block?(self)
+        if let block = block {
+            block(self)
+        } else {
+            finish()
+        }
     }
 
     override func operationDidCancel() {
@@ -39,6 +55,20 @@ class AsyncBlockOperation: AsyncOperation {
         executionBlock = nil
     }
 
+    func setExecutionBlock(_ block: @escaping (AsyncBlockOperation) -> Void) {
+        dispatchQueue.async {
+            assert(!self.isExecuting && !self.isFinished)
+            self.executionBlock = block
+        }
+    }
+
+    func setExecutionBlock(_ block: @escaping () -> Void) {
+        setExecutionBlock { operation in
+            block()
+            operation.finish()
+        }
+    }
+
     func addCancellationBlock(_ block: @escaping () -> Void) {
         dispatchQueue.async {
             if self.isCancelled {
diff --git a/ios/MullvadVPN/Operations/ResultBlockOperation.swift b/ios/MullvadVPN/Operations/ResultBlockOperation.swift
index 4ac88695b5..41e1e8ee77 100644
--- a/ios/MullvadVPN/Operations/ResultBlockOperation.swift
+++ b/ios/MullvadVPN/Operations/ResultBlockOperation.swift
@@ -10,11 +10,16 @@ import Foundation
 
 class ResultBlockOperation<Success, Failure: Error>: ResultOperation<Success, Failure> {
     typealias ExecutionBlock = (ResultBlockOperation<Success, Failure>) -> Void
+    typealias ThrowingExecutionBlock = () throws -> Success
 
     private var executionBlock: ExecutionBlock?
     private var cancellationBlocks: [() -> Void] = []
 
-    convenience init(dispatchQueue: DispatchQueue?, executionBlock: @escaping ExecutionBlock) {
+    convenience init(
+        dispatchQueue: DispatchQueue? = nil,
+        executionBlock: @escaping ExecutionBlock
+    )
+    {
         self.init(
             dispatchQueue: dispatchQueue,
             executionBlock: executionBlock,
@@ -23,6 +28,29 @@ class ResultBlockOperation<Success, Failure: Error>: ResultOperation<Success, Fa
         )
     }
 
+    convenience init(
+        dispatchQueue: DispatchQueue? = nil,
+        executionBlock: @escaping ThrowingExecutionBlock
+    )
+    {
+        self.init(
+            dispatchQueue: dispatchQueue,
+            executionBlock: { operation in
+                do {
+                    let value = try executionBlock()
+
+                    operation.finish(completion: .success(value))
+                } catch {
+                    let castedError = error as! Failure
+
+                    operation.finish(completion: .failure(castedError))
+                }
+            },
+            completionQueue: nil,
+            completionHandler: nil
+        )
+    }
+
     init(
         dispatchQueue: DispatchQueue?,
         executionBlock: @escaping ExecutionBlock,