---
title: LayerHierarchyHostingTransactionCoordinator
framework: browserenginekit
role: symbol
role_heading: Class
path: browserenginekit/layerhierarchyhostingtransactioncoordinator
---

# LayerHierarchyHostingTransactionCoordinator

A class that synchronizes updates to views and layers in different processes.

## Declaration

```swift
class LayerHierarchyHostingTransactionCoordinator
```

## Mentioned in

Hosting browser view layers in the rendering extension

## Overview

Overview Updates to your app’s UI occur through Core Animation’s underlying transaction mechanism. This class works with Core Animation to synchronize transactions that occur across processes in your browser app. To do that: Add views and layer hierarchies to an instance of this class. Share the instance between processes using createXPCRepresentation() and init(xpcRepresentation:), or encode(_:) and init(port:data:). Perform the necessary Core Animation transactions. Call commit() on the instance, and discard it. For more information, see Hosting browser view layers in the rendering extension.

## Topics

### Creating a transaction coordinator

- [init()](browserenginekit/layerhierarchyhostingtransactioncoordinator/init().md)
- [init(coder:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/init(coder:).md)

### Sharing a transaction coordinator using XPC

- [createXPCRepresentation()](browserenginekit/layerhierarchyhostingtransactioncoordinator/createxpcrepresentation().md)
- [init(xpcRepresentation:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/init(xpcrepresentation:).md)

### Sharing a transaction coordinator using Mach

- [encode(_:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/encode(_:).md)
- [init(port:data:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/init(port:data:).md)

### Synchronizing transactions

- [add(_:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/add(_:)-7day0.md)
- [add(_:)](browserenginekit/layerhierarchyhostingtransactioncoordinator/add(_:)-i66q.md)
- [commit()](browserenginekit/layerhierarchyhostingtransactioncoordinator/commit().md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSecureCoding](foundation/nssecurecoding.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Layer hosting

- [Hosting browser view layers in the rendering extension](browserenginekit/hosting-browser-view-layers-in-the-rendering-extension.md)
- [LayerHierarchy](browserenginekit/layerhierarchy.md)
- [LayerHierarchyHostingView](browserenginekit/layerhierarchyhostingview.md)
- [LayerHierarchyHandle](browserenginekit/layerhierarchyhandle.md)