NSExtension NSExtensionAttributes NSExtensionActivationRule SUBQUERY ( extensionItems, $extensionItem, SUBQUERY ( $extensionItem.attachments, $attachment, ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "public.url" ).@count == $extensionItem.attachments.@count ).@count > 0 NSExtensionPointIdentifier com.apple.share-services NSExtensionPrincipalClass $(PRODUCT_MODULE_NAME).ShareViewController