Responder is a Package that provides a way of sending your data through a chain of responsibility using a better protocol implementation based on delegate pattern and a better solution that the Notification Center provides
It's very simple, at first, we just implement Responder protocol where we want to create a linked list based on value type or reference, take a look at the example below:
struct Object: Responder {
var nextResponder: Responder?
}
Basically, we want to send data through this list and we need someone to anwser whether or not they can perform this action. And how can we do this? The idea behind this implementation is to have a fusion of delegate pattern and Notification Center using Chain of Responsibility
Following this example, we need to go through each object and check if we can execute or not execute an action, if not then we check to next element in the chain
protocol ActionProtocol {
func send(event: Action)
}
enum Action: Event {
case here
func sendToHandler(_ handler: ActionProtocol) {
handler.send(event: self)
}
}In this case, the ActionProtocol is just used as a validation protocol that will be executed when found on the chain. An Event is the protocol that we need to implement and that we'll send through the chain, super easy right!
Don't worry, it's much simpler than you imagine!
object.tryToHandle(Action.here)Do you see? it's simple
We can use this to avoid using delegate pattern in which usually we create a property reference to set delegate's values to each coordinator node
Here the use is basic, we can create a linked list and each element can respond a specific action
To use Responder as a Swift Package Manager package just add the following in your Package.swift file.
.package(url: "https://github.com/bfernandesbfs/Responder.git", .upToNextMajor(from: "0.0.1"))