Creating Entry List Screenlet's Connector

Recall that Connectors are Screenlet components that make server calls. Also recall that by making your server calls in Connectors instead of Interactors, you gain an additional layer of abstraction.

In this article, you’ll create Entry List Screenlet’s Connector. Because this Connector is so similar to that of Guestbook List Screenlet, the steps to create it aren’t explained in detail. Focus is instead placed on the few places in the code where the Connectors diverge. For a full explanation of the code, see the article on creating Guestbook List Screenlet’s Connector.

Creating Your Connector’s Folder

Follow these steps to create your Connector’s folder:

1. In the Finder, create the Connector folder inside your project’s EntryListScreenlet folder.

2. Drag and drop the Connector folder from the Finder into your Xcode project, under the EntryListScreenlet folder. In the dialog that appears, select Copy items if needed, Create groups, and the Liferay Guestbook target. Then click Finish. The Connector folder now appears in your project.

Now you’re ready to create the Connector.

Creating the Connector

Recall that list Screenlet Connectors must extend the PaginationLiferayConnector class. Your list Screenlet’s Connector class must also contain any properties it needs to make the server call, and an initializer that sets them. To support pagination, the initializer must also contain the following arguments, which you’ll pass to the superclass initializer:

• startRow: The number representing the page’s first row.
• endRow: The number representing the page’s last row.
• computeRowCount: Whether to call the Connector’s doAddRowCountServiceCall method.

Follow these steps to create Guestbook List Screenlet’s Connector:

1. In the Project navigator, right-click the Connector folder you added above and select New File. In the dialog that appears, fill out each screen as follows:

   • Select iOS → Source → Cocoa Touch Class, and click Next.
   • Name the class EntryListPageLiferayConnector, set it to extend PaginationLiferayConnector, select Swift for the language, and click Next.
   • Make sure the Connector folder and group is selected, as well as the Liferay Guestbook target (these should be selected by default). Click Create.

2. Replace the class file’s contents with this code:

   import UIKit
   import LiferayScreens
   
   class EntryListPageLiferayConnector: PaginationLiferayConnector {
   
       public let groupId: Int64
       public let guestbookId: Int64
   
       //MARK: Initializer
   
       public init(startRow: Int, endRow: Int, computeRowCount: Bool, groupId: Int64, 
           guestbookId: Int64) {
   
               self.groupId = groupId
               self.guestbookId = guestbookId
   
               super.init(startRow: startRow, endRow: endRow, computeRowCount: computeRowCount)
       }
   
       //MARK: PaginationLiferayConnector
   
       public override func doAddPageRowsServiceCall(session: LRBatchSession, startRow: Int, endRow: Int, 
           obc: LRJSONObjectWrapper?) {
   
           let service = LREntryService_v7(session: session)
   
           do {
               try service!.getEntriesWithGroupId(groupId, guestbookId: guestbookId, 
                       start: Int32(startRow), end: Int32(endRow))
           }
           catch {
               // the service method returns nil because the request is sent later, in batch
           }
   
       }
   
       override public func doAddRowCountServiceCall(session: LRBatchSession) {
           let service = LREntryService_v7(session: session)
   
           do {
               try service!.getEntriesCount(withGroupId: groupId, guestbookId: guestbookId)
           }
           catch {
               // the service method returns nil because the request is sent later, in batch
           }
       }
   
   }
   

   This class is almost identical to Guestbook List Screenlet’s Connector class, GuestbookListPageLiferayConnector. The only differences are due to the service calls. To define the guestbook to retrieve entries from, EntryListPageLiferayConnector needs a guestbookId property. It then uses this property with the service methods getEntriesWithGroupId and getEntriesCount to retrieve the entries and number of entries, respectively. Also note that the service is an LREntryService_v7 instance.

Nicely done! Now that Entry List Screenlet has a Connector, you must create its Interactor. The next article shows you how to do this.