Add fileImporter support

Author: carson-katri

Sources/LiveViewNative/Stylesheets/Modifiers/Files/FileImporterModifier.swift

@@ -0,0 +1,127 @@
+//
+//  FileImporterModifier.swift
+//
+//
+//  Created by Carson Katri on 10/23/24.
+//
+
+import SwiftUI
+import LiveViewNativeCore
+import LiveViewNativeStylesheet
+import UniformTypeIdentifiers
+import OSLog
+
+private let logger = Logger(subsystem: "LiveViewNative", category: "_FileImporterModifier")
+
+/// See [`SwiftUI.View/fileImporter(isPresented:allowedContentTypes:allowsMultipleSelection:onCompletion:)`](https://developer.apple.com/documentation/swiftui/view/fileimporter(ispresented:allowedcontenttypes:allowsmultipleselection:oncompletion:)) for more details on this ViewModifier.
+///
+/// ### fileImporter(isPresented:allowedContentTypes:allowsMultipleSelection:onCompletion:)
+/// - `isPresented`: `attr("...")` (required)
+/// - `allowedContentTypes`: `attr("...")` or list of ``UniformTypeIdentifiers/UTType`` (required)
+/// - `allowsMultipleSelection`: `attr("...")` or ``Swift/Bool`` (required)
+///
+/// See [`SwiftUI.View/fileImporter(isPresented:allowedContentTypes:allowsMultipleSelection:onCompletion:)`](https://developer.apple.com/documentation/swiftui/view/fileimporter(ispresented:allowedcontenttypes:allowsmultipleselection:oncompletion:)) for more details on this ViewModifier.
+///
+/// Example:
+///
+/// ```heex
+/// <.live_file_input upload={@uploads.avatar} />
+/// ```
+@_documentation(visibility: public)
+@ParseableExpression
+struct _FileImporterModifier<R: RootRegistry>: ViewModifier {
+    static var name: String { "fileImporter" }
+    
+    @Environment(\.formModel) private var formModel
+    
+    private let id: AttributeReference<String>
+    private let name: AttributeReference<String>
+    @ChangeTracked private var isPresented: Bool
+    private let allowedContentTypes: AttributeReference<UTType.ResolvableSet>
+    private let allowsMultipleSelection: AttributeReference<Bool>
+    
+    @ObservedElement private var element
+    @LiveContext<R> private var context
+
+    @available(iOS 14.0, macOS 11.0, visionOS 1.0, *)
+    init(
+        id: AttributeReference<String>,
+        name: AttributeReference<String>,
+        isPresented: ChangeTracked<Bool>,
+        allowedContentTypes: AttributeReference<UTType.ResolvableSet>,
+        allowsMultipleSelection: AttributeReference<Bool>
+    ) {
+        self.id = id
+        self.name = name
+        self._isPresented = isPresented
+        self.allowedContentTypes = allowedContentTypes
+        self.allowsMultipleSelection = allowsMultipleSelection
+    }
+
+    func body(content: Content) -> some View {
+        #if os(iOS) || os(macOS) || os(visionOS)
+        content.fileImporter(
+            isPresented: $isPresented,
+            allowedContentTypes: allowedContentTypes.resolve(on: element, in: context).values,
+            allowsMultipleSelection: allowsMultipleSelection.resolve(on: element, in: context)
+        ) { result in
+            let id = id.resolve(on: element, in: context)
+            
+            guard let liveChannel = context.coordinator.liveChannel
+            else { return }
+            
+            do {
+                let files = try result.get().map({ url in
+                    LiveFile(
+                        try Data(contentsOf: url),
+                        url.pathExtension,
+                        url.deletingPathExtension().lastPathComponent,
+                        id
+                    )
+                })
+                Task {
+                    do {
+                        for file in files {
+                            try await liveChannel.validateUpload(file)
+                        }
+                    } catch {
+                        logger.log(level: .error, "\(error.localizedDescription)")
+                    }
+                }
+                self.formModel?.fileUploads.append(
+                    contentsOf: files.map({ file in
+                        {
+                            try await liveChannel.uploadFile(file)
+                            print("upload complete")
+                        }
+                    })
+                )
+            } catch {
+                logger.log(level: .error, "\(error.localizedDescription)")
+            }
+        }
+        #else
+        content
+        #endif
+    }
+}
+
+extension UTType: AttributeDecodable {
+    struct ResolvableSet: AttributeDecodable, ParseableModifierValue {
+        nonisolated let values: [UTType]
+        
+        init(values: [UTType]) {
+            self.values = values
+        }
+        
+        nonisolated init(from attribute: LiveViewNativeCore.Attribute?, on element: ElementNode) throws {
+            guard let value = attribute?.value
+            else { throw AttributeDecodingError.missingAttribute(Self.self) }
+            self.values = value.split(separator: ",").compactMap({ UTType(filenameExtension: String($0.dropFirst())) })
+        }
+        
+        static func parser(in context: ParseableModifierContext) -> some Parser<Substring.UTF8View, Self> {
+            Array<String>.parser(in: context).compactMap({ Self.init(values: $0.compactMap(UTType.init)) })
+        }
+    }
+}

Sources/LiveViewNative/ViewModel.swift

@@ -59,11 +59,14 @@ public class FormModel: ObservableObject, CustomDebugStringConvertible {
     /// A publisher that emits a value before sending the form submission event.
     var formWillSubmit = PassthroughSubject<(), Never>()
 
+    var fileUploads: [() async throws -> ()] = []
+    
     init(elementID: String) {
         self.elementID = elementID
     }
 
     @_spi(LiveForm) @preconcurrency public func updateFromElement(_ element: ElementNode, submitAction: @escaping () -> ()) {
+        self.fileUploads.removeAll()
         let pushEventImpl = pushEventImpl!
         self.changeEvent = element.attributeValue(for: .init(name: "phx-change")).flatMap({ event in
             { value in
@@ -95,6 +98,11 @@ public class FormModel: ObservableObject, CustomDebugStringConvertible {
     /// See ``LiveViewCoordinator/pushEvent(type:event:value:target:)`` for more information.
     public func sendSubmitEvent() async throws {
         formWillSubmit.send(())
+        for fileUpload in fileUploads {
+            print("Upload...")
+            try await fileUpload()
+        }
+        print("All uploads done")
         if let submitEvent = submitEvent {
             try await pushFormEvent(submitEvent)
         } else if let submitAction {