Creating the iOS Screenlet's Class

The Screenlet class is the central hub of a Screenlet. It contains the Screenlet’s properties, a reference to the Screenlet’s View class, methods for invoking Interactor operations, and more. When using a Screenlet, app developers primarily interact with its Screenlet class. In other words, if a Screenlet were to become self-aware, it would happen in its Screenlet class (though we’re reasonably confident this won’t happen).

Screens’s BaseScreenlet class is a base Screenlet class implementation. Since BaseScreenlet provides most of a Screenlet class’s required functionality, your Screenlet class should extend BaseScreenlet. This lets you focus on your Screenlet’s unique functionality. Your Screenlet class must also include any @IBInspectable properties your Screenlet requires and a reference to your Screenlet’s View class. To perform your Screenlet’s action, your Screenlet class must override BaseScreenlet’s createInteractor method. This method should create an instance of your Interactor and then set the Interactor’s onSuccess and onFailure closures to define what happens when the server call succeeds or fails, respectively.

For example, the AddBookmarkScreenlet class is the Screenlet class in Add Bookmark Screenlet. This class extends BaseScreenlet and contains an @IBInspectable variable for the bookmark folder’s ID (folderId). The AddBookmarkScreenlet class’s createInteractor method first gets a reference to the View class (AddBookmarkView_default). It then creates an AddBookmarkInteractor instance with this Screenlet class (self), the folderId, the bookmark’s title, and the bookmark’s URL. Note that the View class reference contains the bookmark title and URL that the user entered into the UI. The createInteractor method then sets the Interactor’s onSuccess closure to print a success message when the server call succeeds. Likewise, the Interactor’s onFailure closure is set to print an error message when the server call fails. Note that you’re not restricted to only printing messages here: you should set these closures to do whatever is best for your Screenlet. The createInteractor method finishes by returning the Interactor instance. Here’s the complete AddBookmarkScreenlet class:

import UIKit
import LiferayScreens


public class AddBookmarkScreenlet: BaseScreenlet {

    //MARK: Inspectables

    @IBInspectable var folderId: Int64 = 0

    //MARK: BaseScreenlet

    override public func createInteractor(name name: String?, sender: AnyObject?) -> Interactor? {

        let view = self.screenletView as! AddBookmarkView_default

        let interactor = AddBookmarkInteractor(screenlet: self,
                                           folderId: folderId,
                                           title: view.title!,
                                           url: view.URL!)

        //Called when the Interactor's server call finishes succesfully
        interactor.onSuccess = {
            let bookmarkName = interactor.resultBookmarkInfo!["name"] as! String
            print("Bookmark \"\(bookmarkName)\" saved!")
        }

        //Called when the Interactor's server call fails
        interactor.onFailure = { _ in
            print("An error occurred saving the bookmark")
        }

        return interactor
    }

}

For reference, the sample Add Bookmark Screenlet’s final code is here on GitHub.

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