Rating Screenlet for iOS

Requirements

• Xcode 9.3 or above
• iOS 11 SDK
• Liferay Portal 6.2 CE/EE, Liferay CE Portal 7.0/7.1, Liferay DXP 7.0+
• Liferay Screens Compatibility app (CE or EE/DXP). This app is preinstalled in Liferay CE Portal 7.0/7.1 and Liferay DXP 7.0+.

Compatibility

• iOS 9 and above

Xamarin Requirements

• Visual Studio 7.2
• Mono .NET framework 5.4.1.6

Features

Rating Screenlet shows an asset’s rating. It also lets users update or delete the rating. This Screenlet comes with different Themes that display ratings as thumbs, stars, and emojis.

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
ScreensratingsentryService (Screens compatibility plugin)	getRatingsEntries	With entryId
ScreensratingsentryService (Screens compatibility plugin)	getRatingsEntries	With classPK and className
ScreensratingsentryService (Screens compatibility plugin)	updateRatingsEntry
ScreensratingsentryService (Screens compatibility plugin)	deleteRatingsEntry

Module

• None

Themes

The default Theme uses the CosmosView library to show an asset’s rating. Other custom Themes may use a different component, such as UIButton or others, to show the items.

This screenlet has four different Themes:

1. Like
2. Thumbs (default)
3. Stars
4. Emojis

Figure 1: Rating Screenlet's different Themes.

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 data from the Liferay instance. If a connection issue occurs, the Screenlet uses the delegate to notify the developer about the error. If the Screenlet successfully loads the data, it stores it 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 data from the local cache. If the data 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 data from the Liferay instance. If this succeeds, the Screenlet shows the data to the user and stores it in the local cache for later use. If a connection issue occurs, the Screenlet retrieves the data from the local cache. If the data 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 a possibly outdated version when there’s no connection.
cache-first	The Screenlet loads the data from the local cache. If the data isn’t there, the Screenlet requests it from the Liferay instance 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 possibly outdated) data.

Required Attributes

• entryId

If you don’t use entryId, you must use these attributes:

• className
• classPK

Attributes

Attribute	Data type	Explanation
layoutId	@layout	The ID of the layout to use to show the Theme.
autoLoad	boolean	Whether the rating loads automatically when the Screenlet appears in the app’s UI. The default value is true.
editable	boolean	Whether the user can change the rating.
entryId	number	The primary key of the asset with the rating to display.
className	string	The asset’s fully qualified class name. For example, a blog entry’s className is com.liferay.blogs.kernel.model.BlogsEntry. The className attribute is required when using it with classPK to instantiate the Screenlet..
classPK	number	The asset’s unique identifier. Only use this attribute when also using className to instantiate the Screenlet.
groupId	number	The ID of the site (group) containing the asset.
offlinePolicy	string	The offline mode setting. See the Offline section for details.

Methods

Method	Return	Explanation
loadRatings()	boolean	Starts the request to load the asset’s ratings.

Delegate

Rating Screenlet delegates some events to an object that conforms to the RatingScreenletDelegate protocol. This protocol lets you implement the following methods:

• - screenlet:onRatingRetrieve:: Called when the ratings are received.

• - screenlet:onRatingDeleted:: Called when a rating is deleted.

• - screenlet:onRatingUpdated:: Called when a rating is updated.

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