# UICollectionViewSupplementaryRegistration A registration for the collection view’s supplementary views. ``` @interface UICollectionViewSupplementaryRegistration : NSObject ``` ## Overview Use a supplementary registration to register supplementary views, like headers and footers, with your collection view and configure each view for display. You create a supplementary registration with your supplementary view type and data item type as the registration’s generic parameters, passing in a registration handler to configure the view. In the registration handler, you specify how to configure the content and appearance of that type of supplementary view. The following example creates a supplementary registration for a custom header view subclass. ```objc UICollectionViewSupplementaryRegistration *headerRegistration = [UICollectionViewSupplementaryRegistration registrationWithSupplementaryClass:[HeaderView class] elementKind:@"Header" configurationHandler:^(HeaderView *supplementaryView, NSString *elementKind, NSIndexPath *indexPath) { supplementaryView.label.text = [NSString stringWithFormat:@"%@ for section %ld", elementKind, (long)indexPath.section]; supplementaryView.backgroundColor = UIColor.lightGrayColor; }]; ``` After you create a supplementary registration, you pass it in to [`dequeueConfiguredReusableSupplementaryViewWithRegistration:forIndexPath:`](/documentation/UIKit/UICollectionView/dequeueConfiguredReusableSupplementaryViewWithRegistration:forIndexPath:), which you call from your data source’s [`supplementaryViewProvider`](/documentation/UIKit/UICollectionViewDiffableDataSource-9tqpa/supplementaryViewProvider-swift.property). ```objc self.dataSource.supplementaryViewProvider = ^UICollectionReusableView *(UICollectionView *collectionView, NSString *elementKind, NSIndexPath *indexPath) { return [collectionView dequeueConfiguredReusableSupplementaryViewWithRegistration:headerRegistration forIndexPath:indexPath]; }; ``` You don’t need to call [`register(_:forSupplementaryViewOfKind:withReuseIdentifier:)`](/documentation/UIKit/UICollectionView/register(_:forSupplementaryViewOfKind:withReuseIdentifier:)-661io) or [`register(_:forSupplementaryViewOfKind:withReuseIdentifier:)`](/documentation/UIKit/UICollectionView/register(_:forSupplementaryViewOfKind:withReuseIdentifier:)-9hn73). The registration occurs automatically when you pass the supplementary view registration to [`dequeueConfiguredReusableSupplementaryViewWithRegistration:forIndexPath:`](/documentation/UIKit/UICollectionView/dequeueConfiguredReusableSupplementaryViewWithRegistration:forIndexPath:). > Important: > Don’t create your supplementary view registration inside a ``doc://com.apple.uikit/documentation/UIKit/UICollectionViewDiffableDataSourceReferenceSupplementaryViewProvider`` closure; doing so prevents reuse, and generates an exception in iOS 15 and higher. ## Topics ### Creating a supplementary registration [`+ (instancetype) registrationWithSupplementaryClass:(Class) supplementaryClass elementKind:(NSString *) elementKind configurationHandler:(UICollectionViewSupplementaryRegistrationConfigurationHandler) configurationHandler;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/registrationWithSupplementaryClass:elementKind:configurationHandler:) Creates a supplementary registration for the specified element kind with a registration handler. [`+ (instancetype) registrationWithSupplementaryNib:(UINib *) supplementaryNib elementKind:(NSString *) elementKind configurationHandler:(UICollectionViewSupplementaryRegistrationConfigurationHandler) configurationHandler;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/registrationWithSupplementaryNib:elementKind:configurationHandler:) Creates a supplementary registration for the specified element kind with a registration handler and nib file. [`typedef void (^)(__kindof UICollectionReusableView *, NSString *, NSIndexPath *) UICollectionViewSupplementaryRegistrationConfigurationHandler;`](/documentation/UIKit/UICollectionViewSupplementaryRegistrationConfigurationHandler) A block that handles the supplementary view registration and configuration. ### Querying a supplementary registration [`@property (nonatomic, readonly) UICollectionViewSupplementaryRegistrationConfigurationHandler configurationHandler;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/configurationHandler) The block that handles the supplementary view registration and configuration. [`@property (nonatomic, readonly) NSString * elementKind;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/elementKind) The supplementary view’s element kind. [`@property (nonatomic, readonly, nullable) Class supplementaryClass;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/supplementaryClass) The class associated with the supplementary view. [`@property (nonatomic, readonly, nullable) UINib * supplementaryNib;`](/documentation/UIKit/UICollectionViewSupplementaryRegistration/supplementaryNib) The nib file associated with the supplementary view. ## Relationships ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)