Await

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Swift port of C# Await using Cocoa's Run Loop mechanism.

Await 최신버젼 다운로드

최종 버전 다운로드 (.zip)

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Await
=====

Swift port of C# Await using Cocoa's Run Loop mechanism.

(Useful for unit testing, but needs special care [for application use](#for-application-use))

### Without `Await`

```
showProgressHUD("Start!")     // displays AFTER download finished (you know why)
let image = downloadLargeImageFromWeb()  // OMG downloading from main-thread!!!
showProgressHUD("Finished!")  // displays after download finished
```

```
showProgressHUD("Start!")  // main-thread

// OK let's use dispatch_async then...
dispatch_async(globalQueue) {
    image = downloadLargeImageFromWeb()  // background-thread
    
    dispatch_async(dispatch_get_main_queue()) {
        showProgressHUD("Finished!")  // main-thread

// want more nested blocks here?
    }
}
```

### With `Await`

```
showProgressHUD("Start!")

let image = await { downloadLargeImageFromWeb() }

// because of await's running Run Loop, "Start!" will be displayed immediately here

showProgressHUD("Finished!")  // displays after download finished
```

How to use
----------

### await

```
let image = await { downloadLargeImageFromWeb() }
```

`await` calls dispatch_async for given closure & runs Run Loop until finished.

### await + until

```
var shouldStop = false
var container: SomeContainer

let result = await(until: shouldStop) {
    container.data = nil

dispatch_async(globalQueue) {
        container.data = downloadData()
        shouldStop = true
    }

return container.data
}
```

Use `until` to manually adjust the Run Loop running time.
This is especially useful in combination with async-programming monads like [Promise](http://promises-aplus.github.io/promises-spec/).

Take a look at [PromiseKit](https://github.com/mxcl/PromiseKit) example:

```
import PromiseKit
var promise = Promise<NSData> { (fulfiller, rejecter) in ... }
...

let result = await(until: !promise.pending) { promise.value }
// or, let result = await(promise)
```

### await + timeout

```
let image = await(timeout: 3) { downloadLargeImageFromWeb() }  // returns nil if 3 sec has passed
```

### await + finishable closure

You can even use `finish()` or `finish(returnValue)` inside closure to manually stop running Run Loop instead of using `await + until`.

```
let data = await { finish in
    dispatch_async(queue) {
        let d = downloadData()
        finish(d)  // pass result data
    }
}
```

```
var data: NSData?
await { finish in
    dispatch_async(queue) {
        let d = downloadData()
        data = d
        finish()  // no return
    }
}
```

For application use
-------------------

For applicaiton use, you MUST wrap `await` calls with `async` as follows:

```
async {
    var image = await { downloadLargeImageFromWeb() }
    image = await { filterImage(image) }
}
```

This is to ensure that `await` will not block `dispatch_get_main_queue()`
which often causes UIKit not responding to touches.

#### Limitation

`await + timeout` and *nested awaits* may not finish at proper time inside `async` due to nested RunLoop running.

Await

Await 최신버젼 다운로드

오늘의 추천 프로젝트

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Await 최신버젼 다운로드

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