Adding Actions to the Context Menu

Overview

In your File Provider UI extension’s Info.plist file, you can define custom actions that appear in the context menu when the user long-presses an item while browsing your file provider’s content. When the user selects the action, the system presents a custom user interface element from your File Provider UI extension.

In macOS 11 and later, you can define custom actions directly in the File Provider extension. The system also adds these actions to the context menu; however, when the user selects them, your extension performs the action without presenting any additional UI elements. For more information, see NSFileProviderCustomAction.

Add Actions to the Context Menu

Add an NSExtensionFileProviderActions key to the NSExtension dictionary in your Info.plist file, as shown in the example below.

<key>NSExtensionFileProviderActions</key>
<array>
	<dict>
		<key>NSExtensionFileProviderActionIdentifier</key>
		<string>com.example.MyFileProvider.setRating</string>
		<key>NSExtensionFileProviderActionName</key>
		<string>Rate</string>
		<key>NSExtensionFileProviderActionActivationRule</key>
		<string>SUBQUERY( fileproviderItems, $fileproviderItem, $fileproviderItem.userInfo.rank != nil ).@count > 0</string>
	</dict>
</array>

The NSExtensionFileProviderActions key takes an array of dictionaries. Each dictionary represents a single action, and contains the keys shown in this table.

The following sequence of events occurs when the user selects one of your actions from the context menu:

1. The system instantiates your FPUIActionExtensionViewController subclass.

2. The system calls your view controller’s prepare(forAction:itemIdentifiers:) method. You can override this method to configure the user interface for the selected action.

3. The system presents your view controller to the user.

4. After the user has finished performing the action, you call the provided FPUIActionExtensionContext object’s cancelRequest(withError:) or completeRequest() method to complete the action.

Use Predicates to Enable and Disable Actions

Use the NSExtensionFileProviderActionActivationRule key to enable or disable actions based on the selected file provider item. Set the key’s value to a predicate format string that the system uses to create an NSPredicate object. The system calls the predicate’s evaluate(with:) method, passing in the selected item, a dictionary with a single fileproviderItems key. The value is an array of NSFileProviderItem objects representing the selected items.

You can use predicates to test the value of any of the NSFileProviderItemProtocol object’s properties. For example, the following predicate tests whether the isUploaded property is set to true.

SUBQUERY ( fileproviderItems, $fileproviderItem, $fileproviderItem.uploadded == YES ).@count > 0

You can also use predicates to test custom data that you’ve added to the item’s userInfo dictionary. For example, the following predicate tests whether the com.example.testBit key has been set.

SUBQUERY( fileproviderItems, $fileproviderItem, $fileproviderItem.userInfo."com.example.testBit" == YES ).@count > 0

If a predicate evaluates to true, the context menu includes the action; if false, the context menu doesn’t include the action. For more about creating predicate format strings, see Predicate Format String Syntax.

See Also

Document Browser Customization

• FPUIActionExtensionViewController