DDL List Screenlet for iOS

Requirements

• Xcode 9.0
• iOS 11 SDK
• Liferay Portal 6.2 (CE or EE), Liferay 7.0 CE, Liferay DXP
• Liferay Screens Compatibility plugin (for Liferay Portal CE or Liferay Portal EE).

Compatibility

• iOS 9 and above

Xamarin Requirements

• Visual Studio 7.2
• Mono .NET framework 5.4.1.6

Features

The DDL List Screenlet enables the following features:

• Shows a scrollable collection of DDL records.
• Implements fluent pagination with configurable page size.
• Allows filtering of records by creator.
• Supports i18n in record values.

JSON Services Used

Screenlets in Liferay Screens call JSON web services in the portal. This Screenlet calls the following services and methods.

Service	Method	Notes
ScreensddlrecordService (Screens compatibility plugin)	getDdlRecords	With ddlRecordSetId, or ddlRecordSetId and userId
ScreensddlrecordService (Screens compatibility plugin)	getDdlRecordsCount

Module

• DDL

Themes

• The Default Theme uses a standard UITableView to show the scrollable list. Other Themes may use a different component, such as UICollectionView or others, to show the items.

Portal Configuration

Dynamic Data Lists (DDL) and Data Types should be configured in the portal. For more details, please refer to the Liferay User Guide sections Defining Data Types and Creating Data Lists.

Offline

This Screenlet supports offline mode so it can function without a network connection. For more information on how offline mode works, see the tutorial on its architecture. Here are the offline mode policies that you can use with this Screenlet:

Policy	What happens	When to use
remote-only	The Screenlet loads the list from the portal. If a connection issue occurs, the Screenlet uses the delegate to notify the developer about the error. If the Screenlet successfully loads the list, it stores the data in the local cache for later use.	Use this policy when you always need to show updated data, and show nothing when there’s no connection.
cache-only	The Screenlet loads the list from the local cache. If the list isn’t there, the Screenlet uses the delegate to notify the developer about the error.	Use this policy when you always need to show local data, without retrieving remote information under any circumstance.
remote-first	The Screenlet loads the list from the portal. If this succeeds, the Screenlet shows the list to the user and stores it in the local cache for later use. If a connection issue occurs, the Screenlet retrieves the list from the local cache. If the list doesn’t exist there, the Screenlet uses the delegate to notify the developer about the error.	Use this policy to show the most recent version of the data when connected, but show an outdated version when there’s no connection.
cache-first	The Screenlet loads the list from the local cache. If the list isn’t there, the Screenlet requests it from the portal and notifies the developer about any errors that occur (including connectivity errors).	Use this policy to save bandwidth and loading time in case you have local (but probably outdated) data.

Required Attributes

• recordSetId
• labelFields

Attributes

Attribute	Data type	Explanation
recordSetId	number	The ID of the DDL being called. To find the IDs for your DDLs, click Admin → Content from the Dockbar. Then click Dynamic Data Lists. Each DDL’s ID is in the table’s ID column.
userId	number	The ID of the user to filter records on. Records aren’t filtered if the userId is 0. The default value is 0.
labelFields	string	The comma-separated names of the DDL fields to show. Refer to the list’s data definition to find the field names. To do so, click Admin → Content from the Dockbar. Then click Dynamic Data Lists and click the Manage Data Definitions button. You can view the fields by clicking on any of the data definitions in the table that appears. Note that the appearance of these values depends on the Theme selected by the user.
offlinePolicy	string	The offline mode setting. The default value is remote-first. See the Offline section for details.
autoLoad	boolean	Whether the list loads automatically when the Screenlet appears in the app’s UI. The default value is true.
refreshControl	boolean	Whether a standard iOS UIRefreshControl appears when the user performs the pull to refresh gesture. The default value is true.
firstPageSize	number	The number of items retrieved from the server for display on the first page. The default value is 50.
pageSize	number	The number of items retrieved from the server for display on the second and subsequent pages. The default value is 25.
obcClassName	string	The name of the OrderByComparator class to use to sort the results. Omit this property if you don’t want to sort the results. You can only use comparator classes that extend OrderByComparator<DDLRecord>. You can also create your own comparator classes that extend OrderByComparator<DDLRecord>.

Methods

Method	Return	Explanation
loadList()	boolean	Starts the request to load the list of records. The list is shown when the response is received. This method returns true if the request is sent.

Delegate

The DDL List Screenlet delegates some events in an object that conforms to the DDLListScreenletDelegate protocol. This protocol lets you implement the following methods:

• - screenlet:onDDLListResponseRecords:: Called when a page of contents is received. Note that this method may be called more than once; once for each retrieved page.

• - screenlet:onDDLListError:: Called when an error occurs in the process. The NSError object describes the error.

• - screenlet:onDDLSelectedRecord:: Called when an item in the list is selected.