Navigation

As you can see on the Example App structure diagram above, each Coordinator has its own UIViewController and only the Coordinators "talk" to each other, the UIViewControllers are isolated from each other.

So how do you tell the Coordinator where to navigate after the user taps a button (or a UITableViewCell)? You emit an Event. Like the following example

Definition

Similar to the way we did it above, we just add a new Event to the Teams domain scope

struct AppEvents {
    ...

    enum Teams: CoordinateEvents, Equatable {
        ...
        case setFavorite(_ team: Team)
        case didSelect(_ team: Team)
        ...
    }

}

Emission

In this case inside a UITableViewController

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    if data.indices.contains(indexPath.row) {
        let team = data[indexPath.row]

        emitEvent(AppEvents.Teams.didSelect(team))
    }
}

and Interception

In this case, inside the Coordinator that manages the UINavigationController so that it can tell that UINavigationController that it should show the desired screen

override func interceptEvent(_ event: CoordinateEvents) -> Bool {
    if let event = event as? AppEvents.Teams {
        if case .didSelect(let team) = event {
            self.goTo(.team(team))
        }
        return false
    }
    ...
}    

As you can start to realize, this is much better than using segues or telling the parent navigationController how to present the next UIViewController because you do not have to make your UIViewControllers aware of the navigation flow, they do not need to know that they are a child of a UINavigationController or that what next screen in the navigation flow, in fact, they do not know anything about their surroundings, making them trully encapsulated and re-usable.