Each

Elegant ⏱ interface for Swift apps

Each is a NSTimer bridge library written in Swift.

• Features
• Requirements
• Installation
• Usage
• Leaks
• License

Features

• Completely configurable timers
• Support for time intervals in ms, seconds, minutes and hours
• Fully extendable
• More readable and simple to use in comparison with NSTimer object

Requirements

• iOS 8.0+ / macOS 10.10+ / tvOS 9.0+ / watchOS 2.0+
• Xcode 8.0+
• Swift 3.0+

Installation

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ gem install cocoapods

CocoaPods 1.1.0+ is required to build Each.

To integrate Each into your Xcode project using CocoaPods, specify it in your Podfile:

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '10.0'
use_frameworks!

target '<Your Target Name>' do
pod 'Each', '~> 1.2'
end

Then, run the following command:

$ pod install

Carthage

You can use Carthage to install Each by adding it to your Cartfile:

github "dalu93/Each"

Usage

Creating a new timer instance

let timer = Each(1).seconds     // Can be .milliseconds, .seconds, .minute, .hours  

Performing operations

timer.perform {
    // Do your operations
    // This closure has to return a NextStep value
    // Return .continue if you want to leave the timer active, otherwise
    // return .stop to invalidate it
}

If you want to leave the memory management decision to the Each class, you can simply use the perform(on: _) method. It requires that the parameter is an AnyObject instance.

timer.perform(on: self) {
    // Do your operations
    // This closure has to return a NextStep value
    // Return .continue if you want to leave the timer active, otherwise
    // return .stop to invalidate it
}

Stopping the timer manually

timer.stop()    // This stops immediately the timer

Restarting the timer

You can restart the timer only after you stopped it. This method restarts the timer with the same perform closure.

timer.restart()

Leaks

Unfortunately the interface doesn't help you with handling the memory leaks the timer could create. In case of them, two workarounds are provided

Workaround 1

Use the perform(on: _) method as explained in the usage section. Please note that using this method, the timer isn't immediately deallocated when the owner is deallocated. It will be deallocated when the timer triggers the next time and it will check whether the owner instance is still valid or not.

Workaround 2

In case you don't want to declare a property that holds the Each reference, create a normal Each timer in your method scope and return .stop/true whenever the owner instance is nil

Each(1).seconds.perform { [weak self] in
    guard let _ = self else { return .stop }

    print("timer called")
    return .continue
}

90% of closures will call self somehow, so this isn't so bad

Workaround 3

In case the first workaround wasn't enough, you can declare a property that holds the Each reference and call the stop() function whenever the owner is deallocated

final class ViewController: UIViewController {
    private let _timer = Each(1).seconds

    deinit {
        _timer.stop()
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        _timer.perform {
            // do something and return. you can check here if the `self` instance is nil as for workaround #1
        }
    }
}

License

Each is released under the MIT license. See LICENSE for details.