Emit is a simple signals library for Swift. It lets you emit strongly-typed events and you don't have to worry about disposing of subscriptions. Emit supports emit/subscribe, map, and filter. Which makes it ideal for keeping your code simple.
Emit has been developed for use in the Hootsuite iOS app.
Attention: Users of Emit
We would like to inform you that Emit library has been deprecated and will no longer be maintained as of September 1, 2024. This decision was made after careful consideration due to availability of better alternatives, i.e. Combine
- No New Features: There will be no further development of new features for Emit.
- Migration Recommendations: We recommend users to migrate to Combine which has similar functionality and will be supported by Apple.
- July 22, 2024: Official deprecation announced.
- September 1, 2024: End of support and maintenance.
- Strongly-typed events
- Mapping and filtering of signals
- Observable variables
- iOS 11.0+, macOS 10.12+, tvOS 10.0+
- Xcode 10.1+
To create a signal you specify the event type that will passed to the subscription closure. You can also specify Void if you don't want to include an event.
// Create a signal
let loginCompleteSignal = Signal<Bool>()To subscribe to a signal you pass an owner. The owner needs to be an object (an instance of a class as opposed to a struct). When the owner gets released the subscriptions stops automatically. You may also pass a DispatchQueue that you would like the closure to be called on, the default is DispatchQueue.main.
// Subscribe to it
loginCompleteSignal.subscribe(owner: self) { result in
// Handle signal
}To emit a signal simply call emit with the event value. Note that subscribers will be called on the next run loop of their specified queue.
// Emit an event
loginCompleteSignal.emit(true)Observable variables combine a value and a signal. The signal gets emitted every time the value changes.
let email = ObservableVariable("")
email.signal.subscribe(owner: self) { newEmail in
// Update UI with new email
}
email.value = "test_email@gmail.com" // This will emit the signal to update the UISee the demo project provided for example usage of the Emit framework.
Emit can be installed using either Carthage or CocoaPods.
To integrate Emit into your Xcode project using Carthage, specify it in your Cartfile:
github "hootsuite/Emit"
First, add the following line to your Podfile:
pod 'Emit'
Second, install Emit into your project:
pod install
Emit is released under the Apache License, Version 2.0. See LICENSE.md for details.