It would be useful to see then .dot file that was used to generate SwiftTask/Screenshots/diagram.png.

Can you help please? Found some case when failure block is called after task is fulfilled. I don't understand how could it be possible but from stacktrace of XCode cancel method is called from task deinit. This cause the task to be handled as canceled in my code, but I has fulfilled it. I don't understand what I made wrong.

I would recommend adding a link to https://ios-developers.slack.com, but perhaps a more focused team could be useful too.

Partially done in #54.

I will follow the same configuration as https://github.com/ReactKit/SwiftState.

Is it possible to run the Promise-Closure on the main thread? Sometimes I want to perform a UI asynchronous operation like requesting permissions to user etc. If those are runned in separate threads, they are not shown to the user... I wasn't able to found any solution in documentation or sourcecode

Hi,
Can you update podfile to support for cocoapods 0.36 beta?

http://blog.cocoapods.org/Pod-Authors-Guide-to-CocoaPods-Frameworks/

Author Note

Currently swift/1.2 branch is running for Xcode6.3-beta (Swift 1.2) support.

Using XCode9 GM to compile SwiftTask swift3 branch with "swift version to 3.2", error as the topic

Now retry will retry task immediately, but in some case, we want to have interval.
I propose you to make following two.

• delay(interval: NSTimeInterval) -> Task
• retry(maxRetryCount: Int, delayInterval: NSTimeInterval = default) -> Task

When calling Task.all() with many tasks and one of the task was failed, canceling all tasks process will start. But from the current algorithm, it makes recursive call. If the number of tasks is 10000 and the first task is failed, the depth of call is about 10000 and it causes stack overflow. So, the proposal is that prepare flag for limiting the depth of call to be 1.

            }.failure { (errorInfo: ErrorInfo) -> Void in

                    lock.lock()
                    _reject(errorInfo)

                    for task in tasks {
                        task.cancel()  // <- this call invokes ".failure" of another task in the same context
                    }
                    lock.unlock()
            }

Hi!

Again thanks for you work on the lib :) I'm still learning Reactive Programming, and I wonder if you could assist me on how to do something I encounter all the time.

Let's say you have one stream, which does some asynchronous work, gives a successful value and fulfills.

And then somewhere else you want to continue doing something after this, with another stream.

If you connect both streams with flatMap, the second stream will terminate as well, which is not what I intended.

What do you recommend to use in this case?

Thanks!

Is this task support Asynchronization operation

Maybe I'm completely confused about the way this works, but shouldn't a failureClosure return Void? Currently, it's trying to return the Value type.

The README shows failure returning Void, which makes sense. Why is the failureClosure returning the value? If the task has failed, shouldn't there be no value?

I'm unable to use this, because, for the task I'm trying to create, if the task has failed, I can't return a value, since the value doesn't exist.

would be great to have a zip function that takes two tasks with different progress, value and error types and returns a task that returns a tuple of values.

I've implemented the function with the signature

public class func zip<P1, V1, R1, P2, V2, R2>(task1: Task<P1, V1, R1>, _ task2: Task<P2, V2, R2>) -> Task<(P1, P2), (V1, V2), (R1?, R2?)>

but unfortunately I'm unable to call it without the error:

Cannot invoke 'zip' with an argument list of type '(Task<Void, String, String>, Task<Void, String, String>)'

Plenty of breaking there. Anyone working on this?

I see that there is a branch for Swift 3 support open. What is the roadmap for having the Swift 3 branch merged and available publicly via cocoapods?

(Specifically, looking to consume the library in a podspec, where the branch cannot be specified)

Is it possible to retain task while it is executed in one scope? I have found that tasks deinit after creating )) even they are returned from success block of other task. Probably we need something that will retain task while it is executing like in next example:

public class Task<Progress, Value, Error> {

    //...

    class func createTask<Progress, Value, Error>(initClosure: InitClosure) -> Task<Progesss, Value, Error> {
        // Paused
        let task = Task<Progesss, Value, Error>(paused: true, initClosure: initClosure)
        task.onFinish = {
            TasksRegistry.unregister(task) // Release
        }
        TasksRegistry.register(task) // Retain
        return task
    }

    //...
}

Or is there any other ways to do so?

Is there easy way to make some manager around task? For example - i created about ten tasks with Alamofire.upload and some other stuff. I should put them in array and remove each value in success closure, so if array clear - all tasks complete successfully.
Problem, is that i can't to smth like this
let uploadTask = LoadImageTask(attachId: event.postId!, attachUrl: "events/(event.postId)/photos",
image: image)
.success({ (let imageId) -> Void in
self.tasksQueue.removeObject(uploadTask)
})
Variable use inside it's own initial value.
How i can deal with it?

As discussed in https://gist.github.com/tokorom/19ae87acf9db5386c0e1 by @tokorom,

self.request1()
    .success { _ -> Task<Progress, Int, Bool> in
        // A
        return self.request2()
    }
    .success { _ in
        // B
    }

(B) gets called first before self.request2() completes.
This occurs when func request1() and func request2() returns Task type with different Error type,
so that type-inference will fail and uses "map" version of then rather than "flatMap" version of it.

We need more strict type constraint to avoid this issue, or add an alias method name to distinguish two methods.

I am able to build and run just fine on simulator and device, but get a segmentation fault only when I try to archive for App Store submission on this line:

@discardableResult public func progress(_ progressClosure: @escaping (ProgressTuple) -> Void) -> Self
{
    var dummyCanceller: Canceller? = nil
    return self.progress(&dummyCanceller, progressClosure)
}

This is the exact error:

@_TTSf4g_n___TTSg5CSo8Progress_T__Ps5Error____TFC9Concierge4Task8progressfFT11oldProgressGSqx_11newProgressx_T_DGS0_xq_q0__ for 'progress' at /Users/pritesh/sampleApp/Vendor/SwiftTask/SwiftTask/SwiftTask.swift:359:31

I'd like to make a pull request to add support for Swift 3.0 to SwiftTask. Could you make a swift/3.0 branch for me to merge into? Thanks!

Under the following conditions, last then not called.

• Task.all chain more than once
• all tasks is empty

what would be a good way to do it?

Sample code

final class Image {
  let url: String

  var downloaded: Bool = false
  var converted: Bool = false

  typealias DownloadTask = Task<NSProgress, String, NSError?>
  typealias ConvertTask = Task<NSProgress, String, NSError?>

  init(url: String) {
    self.url = url
  }

  func download() -> DownloadTask {
    return DownloadTask { progress, fulfill, reject, configure in
      // download image and cache
      self.downloaded = true
      return fulfill("path to image")
    }
  }

  func convert() -> ConvertTask {
    return ConvertTask { progress, fulfill, reject, configure in
      // convert image
      self.converted = true
      return fulfill("path to converted image")
    }
  }
}

func downloadAndConvertAll() {
  let images = [
    Image(url: "http://example.com/1.jpg"),
    Image(url: "http://example.com/2.jpg"),
    Image(url: "http://example.com/3.jpg"),
  ]

  // I want to exclude downloaded image
  let downloadTasks = images.filter { !$0.downloaded }.map { $0.download() }

  // downloadTasks.count == 0 and convertTasks.count == 0 => doSomething not called
  Task.all(downloadTasks).then { _ -> Task<Image.ConvertTask.BulkProgress, [String], NSError?> in
    // I want to exclude converted image
    let convertTasks = images.filter { !$0.converted }.map { $0.convert() }
    return Task.all(convertTasks)
  }.then { _ in
    doSomething()
  }
}

func doSomething() {
  print("doSomething")
}

found workaround

Task.all(downloadTasks.count > 0 ? downloadTasks : [Image.DownloadTask(value: "dummy")])

and

Task.all(convertTasks.count > 0 ? convertTasks : [Image.ConvertTask(value: "dummy")])

It seems to work.

I'm using ReactKit (Swift/2.0 branch) through cocoapods in my xcode project.
I'm getting below error while trying to build. (_Xcode7.0 beta6, Swift2.0_)

Cannot express tuple conversion '(error: Error?, isCancelled: Bool)' (aka '(error: Optional, isCancelled: Bool)') to '(error: Error??, isCancelled: Bool)' (aka '(error: Optional<Optional>, isCancelled: Bool)')

I've tried to fix this like below

public func success<Progress2, Value2, Error2, C: Canceller>(inout canceller: C?, _ successClosure: Value -> Task<Progress2, Value2, Error2>) -> Task<Progress2, Value2, Error>
    {
        return Task<Progress2, Value2, Error> { [unowned self] newMachine, progress, fulfill, _reject, configure in

            let selfMachine = self._machine

            // NOTE: using `self._then()` + `selfMachine` instead of `self.then()` will reduce Task allocation
            self._then(&canceller) {
                if let value = selfMachine.value.rawValue {
                    let innerTask = successClosure(value)
                    _bindInnerTask(innerTask, newMachine: newMachine, progress: progress, fulfill: fulfill, _reject: _reject, configure: configure)
                }
                else if let errorInfo = selfMachine.errorInfo.rawValue {
                    _reject(ErrorInfo(errorInfo.error, errorInfo.isCancelled))
                }
            }
        }.name("\(self.name)-success")
    }

however, I'm still have below error. I'm not sure how can I change return expression.

Cannot convert return expression of type 'Task<Progress2, Value2, Error?>' (aka 'Task<Progress2, Value2, Optional>') to return type 'Task<Progress2, Value2, Error>'

Thank you in beforehand.

I am having problems getting progress events to propagate up the chain of tasks.

I have a lower level String task that will generate progress. Then, upon success I want to convert that String value to in Int if possible or an error otherwise. I expect progress handlers on both tasks to be called whenever progress changes on the lower level task. Is this a valid expectation?

To be clear, consider the following test (using Nimble) that always fails where indicated below:

class ProgressTest: QuickSpec {
    override func spec() {
        var stringTask: Task<Float, String, NSError>!
        var stringTaskProgressHandler: (Float ->Void)?
        var stringTaskProgressValue: Float?

        var intTask: Task<Float, Int, NSError>!
        var intTaskProgressValue: Float?

        beforeEach {
            stringTask = Task<Float, String, NSError> { progress, fulfill, reject, configure in
                stringTaskProgressHandler = progress
            }.progress { oldValue, newValue in
                stringTaskProgressValue = newValue
            }

            intTask = stringTask.success { stringValue -> Task<Float, Int, NSError> in
                if let intValue = Int(stringValue) {
                    return Task(value: intValue)
                } else {
                    return Task(error: NSError(domain: "test", code: 123, userInfo: nil))
                }
            }.progress { oldValue, newValue in
                intTaskProgressValue = newValue
            }
        }

        describe("when string task has progress") {
            beforeEach {
                stringTaskProgressHandler?(0.5)
            }

            it("string task progress should fire") {
                expect(stringTaskProgressValue).toEventually(equal(0.5))
            }
            it("should propagate progress to intTask") {
                // ************ This test fails! ************
                expect(intTaskProgressValue).toEventually(equal(0.5))
            }
        }
    }
}

Thoughts?

When compiling my project's main target, Xcode sometimes compiles the SwiftTask's Carthage/Checkouts directory, which includes outdated libraries. In my case, this breaks my build because the version of Alamofire doesn't compile under Swift 1.2. The only fix I've found is to delete these checkouts sources locally.

This may be a problem in my project configuration, but it seems like these sources should be kept up-to-date or removed.

I'm sorry for asking in potentially the wrong place, but I haven't been able to completely cancel a task that I started with task.try().

I have tasks that belong to table view cells, and so I'm looking for the way to cancel/abort a task that is running on a cell that is about to scroll off of the screen and therefore no longer needs to be running (as it is now in the background).

Is there a way to cancel/abort/kill a task?

Not sure is it clear how to cancel task from its initClosure block. I can manage progress, configure, reject or fullfill but it is absent or not so clear described in documentation how to cancel it. For example:

let task = Task<Float, Int, ErrorType>(paused: true) { (progress, fulfill, reject, configure) in
    progress.cancel() // should be something like this ?
}

I tried both Carthage and Pod and both failed to compile in the end.

Is there support yet for Swift 4.1 or when is it planned?

Please delete.