A simple property wrapper over PassthroughSubject
Published Event
A simple property wrapper over PassthroughSubject to create publishable properties that don’t emit value right after subscription.
? Installation
Add PublishedEvent directory from this repository into your project and that’s it!
? How to use
The following example show how to declare Event variable and subscribe on it.
❗️ Pay attention that even though value has optional type on declaration, it is not optional in subscription!
/// Declaration
/// Make it `private(set)` to restrict changing value outside of the class
@Event private(set) var updateStringEvent: String?
/// Subscription
/// This subscription won't emit right after subscription as `PassthroughSubject` does.
subscription = $updateStringEvent.sink { value in
// Value is not optional!
print("New value is \(value)")
}
/// Emit value
updateStringEvent = "I love publishers ?"
It was the example with usual data. But how to declare Event with optional data type? Things are simple – just add the second optional ?
/// Declaration
/// Make it double-optional to get optional value in subscription
@Event private(set) var updateStringEvent: String??
/// Subscription
subscription = $updateStringEvent.sink { value in
if let value = value {
print("New value is \(value)")
} else {
print("New value is null")
}
}
/// Emit value
updateStringEvent = nil // or some string value
And the last example, how to use it if we want to just emit some event, without value. The answer is – just make the Void type!
/// Declaration
@Event private(set) var dataLoadedEvent: Void?
/// Subscription
subscription = $dataLoadedEvent.sink {
print("Data was loaded")
}
/// Emit value
updateStringEvent = ()