# FileWrapperDocumentReader A document reader that deserializes a `FileWrapper` into a snapshot. ``` struct FileWrapperDocumentReader ``` ## Overview This is the recommended reader for most documents. Provide a closure that converts a `FileWrapper` into your snapshot type, and `FileWrapperDocumentReader` handles file coordination and loading. ``` func reader(configuration: sending ReadConfiguration) -> sending FileWrapperDocumentReader { FileWrapperDocumentReader(configuration) { fileWrapper in guard let data = fileWrapper.regularFileContents else { throw CocoaError(.fileReadCorruptFile) } return String(decoding: data, as: UTF8.self) } } ``` For package documents, navigate the `FileWrapper` hierarchy: ``` FileWrapperDocumentReader(configuration) { directory in let children = directory.fileWrappers ?? [:] guard let metadataData = children["metadata.json"]? .regularFileContents else { throw CocoaError(.fileReadCorruptFile) } return try JSONDecoder().decode( Metadata.self, from: metadataData ) } ``` > Important: `FileWrapper` loads file contents on demand. A > child file may be gone by the time you call > `regularFileContents`. Always handle errors when reading > children of a package. The closure does not receive a `Subprogress`. To report progress during reads, use a custom [`DocumentReader`](/documentation/SwiftUI/DocumentReader) instead. ## Topics ### Creating a reader [`init(_:makeSnapshot:)`](/documentation/SwiftUI/FileWrapperDocumentReader/init(_:makeSnapshot:)) Creates a reader that converts a `FileWrapper` into a snapshot. [`ReadConfiguration`](/documentation/SwiftUI/FileWrapperDocumentReader/ReadConfiguration) ### Reading a document ## Relationships ### Conforms To [`DocumentReader`](/documentation/SwiftUI/DocumentReader) --- 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)