ELDispatch

Note: This framework is no longer being actively maintained and will not be updated for future versions of Swift or iOS.

ELDispatch is a Swift framework that provides useful Swift language constructs to oft-used Grand Central Dispatch patterns such as Queues, Groups, Timer, Semaphore, etc.

Grand Central Dispatch is a powerful library, but it can easily be difficult for someone to grasp how to use it well. With Swift, we can provide language constructs such as enumerations to allow dispatching closures to various prenamed priorities, such as .Background. We can also make using GCD groups easier through function chaining.

Requirements

ELDispatch requires Swift 2.3, Xcode 8 and depends on ELFoundation.framework.

Installation

Carthage

Install with Carthage by adding the framework to your project's Cartfile.

github "Electrode-iOS/ELDispatch"

Manual

Install manually by adding ELDispatch.xcodeproj to your project and configuring your target to link ELDispatch.framework.

Getting Started

ELDispatch was heavily influenced by John Estropia's GCDKit (https://github.com/JohnEstropia/GCDKit). We love the work he's done, despite having taken a slightly different direction in syntax and implementation.

The following constructs have been implemented:

• Dispatch: An abstraction of the dispatch_* APIs.
• DispatchQueue: An abstraction of the dispatc_queue_* APIs.
• DispatchClosure: An abstraction of the dispatch_block_* APIs.
• DispatchGroup: An abstraction of the dispatch_group_* APIs.
• DispatchTimer: A struct implementing a GCD timer using the dispatch_source_* APIs.
• DispatchSemaphore: An abstraction of the dispatch_semaphore_* APIs.

Common Usage

Executing a run-of-the-mill asynchronous closure:

Dispatch().async(.Background) {
    doSomething()
}

Executing an asynchronous closure on a background queue and notifying the main thread when it's completed:

Dispatch().async(.Background) {
    doSomething()
}.notify(.Main) {
    dearMainThreadImDone()
}

Executing an asychronous closure and waiting for 3 seconds:

Dispatch().async(.Background) {
    doSomething()
}.wait(3) == false {
    itTimedOutImSad()
} else {
    itWasSuccessfulAndMyLifeHasMeaning()
}

Executing a few async tasks as a group and waiting indefinitely:

DispatchGroup().async(.Background) {
    doSomething(1)
}.async(.Utility) {
    doSomething(2)
}.async(.High) {
    doSomethingUrgently(3)
}.wait()

or...

let group = DispatchGroup()

group.async(.Background) {
    doSomething(1)
}.async(.Utility) {
    doSomething(2)
}.async(.High) {
    doSomethingUrgently(3)
}

if group.wait(10) == true {
    handstandAndCartwheel()
}

Execute an asynchronous task, synchronously with a Semaphore:

let semaphore = DispatchSemaphore(initialValue: 0)
        
// start a NSURLSession to get some data from our imaginary command line tool.
let task = session.dataTaskWithRequest(request) { (data, response, error) -> Void in
    if data != nil {
        let dataString: String = NSString(data: data, encoding: NSUTF8StringEncoding)! as String
        json = JSON(string: dataString)
    }
            
    semaphore.signal()
}
        
task.resume()
        
semaphore.wait()

Contributions

We appreciate your contributions to all of our projects and look forward to interacting with you via Pull Requests, the issue tracker, via Twitter, etc. We're happy to help you, and to have you help us. We'll strive to answer every PR and issue and be very transparent in what we do.

When contributing code, please refer to our Dennis (https://github.com/Electrode-iOS/Dennis).

License

The MIT License (MIT)

Copyright (c) 2015 Walmart and other Contributors

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.