AppDelegate
is a traditional example of bad code. Lots of line of code that makes so much different things are put together in methods that are called within the application life cycle. But all of those concerns are over.
Using PluggableApplicationDelegate
you decouple AppDelegate from the services that you plug to it. Each ApplicationService
has its own life cycle that is shared with AppDelegate
.
Let see some code.
Here is how a ApplicationService
is like:
import Foundation
import PluggableApplicationDelegate
final class LoggerApplicationService: NSObject, ApplicationService {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
print("It has started!")
return true
}
func applicationDidEnterBackground(_ application: UIApplication) {
print("It has entered background")
}
}
That's all. It is exactly the same as a AppDelegate. Think of ApplicationService
as sub-AppDelegates.
In AppDelegate
you just have to inherit from PluggableApplicationDelegate to register the services.
import UIKit
import PluggableApplicationDelegate
@UIApplicationMain
class AppDelegate: PluggableApplicationDelegate {
override var services: [ApplicationService] {
return [
LoggerApplicationService()
]
}
}
Yes. That's all. Simple.
You may want to read my Medium post about Pluggable App Delegate. Basically, you do an inversion of control. Instead of let AppDelegate instantiate your dependencies, perform actions at every step of its life cycle, you create objects that share the AppDelegate life cycle and plug them into your AppDelegate. Those objects are observers of the AppDelegate. Your AppDelegate has the only responsibility of notify them about its life cycle events.
To run the example project, clone the repo, and run pod install
from the Example directory first.
PluggableApplicationDelegate requires Swift 3.0 or above.
PluggableApplicationDelegate is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'PluggableApplicationDelegate'
fmo91, ortizfernandomartin@gmail.com
PluggableApplicationDelegate is available under the MIT license. See the LICENSE file for more info.