feat(dialog): add `showFolderPicker`

.changes/dialog-ios-fix.md

@@ -0,0 +1,6 @@
+---
+"dialog": patch
+"dialog-js": patch
+---
+
+Add support for folder picker on iOS.

plugins/dialog/ios/Sources/DialogPlugin.swift

@@ -38,6 +38,14 @@ struct SaveFileDialogOptions: Decodable {
   var defaultPath: String?
 }
 
+struct FolderPickerOptions: Decodable {
+  var title: String?
+  var defaultPath: String?
+  var multiple: Bool?
+  var recursive: Bool?
+  var canCreateDirectories: Bool?
+}
+
 class DialogPlugin: Plugin {
 
   var filePickerController: FilePickerController!
@@ -168,6 +176,47 @@ class DialogPlugin: Plugin {
     }
   }
 
+  @objc public func showFolderPicker(_ invoke: Invoke) throws {
+    let args = try invoke.parseArgs(FolderPickerOptions.self)
+    
+    onFilePickerResult = { (event: FilePickerEvent) -> Void in
+      switch event {
+      case .selected(let urls):
+        invoke.resolve(["directories": urls])
+      case .cancelled:
+        invoke.resolve(["directories": nil])
+      case .error(let error):
+        invoke.reject(error)
+      }
+    }
+
+    DispatchQueue.main.async {
+      let picker: UIDocumentPickerViewController
+      if #available(iOS 14.0, *) {
+        picker = UIDocumentPickerViewController(forOpeningContentTypes: [.folder])
+      } else {
+        picker = UIDocumentPickerViewController(documentTypes: [kUTTypeFolder as String], in: .open)
+      }
+      
+      if let title = args.title {
+        picker.title = title
+      }
+      
+      if let defaultPath = args.defaultPath {
+        picker.directoryURL = URL(string: defaultPath)
+      }
+      
+      picker.delegate = self.filePickerController
+      picker.allowsMultipleSelection = args.multiple ?? false
+      
+      // Note: canCreateDirectories is only supported on macOS
+      // recursive is handled at the filesystem access level, not in the picker
+      
+      picker.modalPresentationStyle = .fullScreen
+      self.presentViewController(picker)
+    }
+  }
+
   private func presentViewController(_ viewControllerToPresent: UIViewController) {
     self.manager.viewController?.present(viewControllerToPresent, animated: true, completion: nil)
   }

plugins/dialog/ios/Sources/FilePickerController.swift

@@ -7,6 +7,7 @@ import MobileCoreServices
 import PhotosUI
 import Photos
 import Tauri
+import UniformTypeIdentifiers
 
 public class FilePickerController: NSObject {
   var plugin: DialogPlugin
@@ -118,6 +119,15 @@ public class FilePickerController: NSObject {
 
 extension FilePickerController: UIDocumentPickerDelegate {
 	public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
+		// Check if this is a folder picker by examining the URLs
+		let isFolder = urls.first?.hasDirectoryPath ?? false
+		
+		if isFolder {
+			self.plugin.onFilePickerEvent(.selected(urls))
+			return
+		}
+		
+		// Handle regular files
 		do {
 			let temporaryUrls = try urls.map { try saveTemporaryFile($0) }
 			self.plugin.onFilePickerEvent(.selected(temporaryUrls))

plugins/dialog/src/commands.rs

@@ -16,9 +16,9 @@ use crate::{
 #[derive(Serialize)]
 #[serde(untagged)]
 pub enum OpenResponse {
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     Folders(Option<Vec<FilePath>>),
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     Folder(Option<FilePath>),
     Files(Option<Vec<FilePath>>),
     File(Option<FilePath>),
@@ -133,7 +133,7 @@ pub(crate) async fn open<R: Runtime>(
     }
 
     let res = if options.directory {
-        #[cfg(desktop)]
+        #[cfg(any(desktop, target_os = "ios"))]
         {
             let tauri_scope = window.state::<tauri::scope::Scopes>();
 
@@ -165,7 +165,7 @@ pub(crate) async fn open<R: Runtime>(
                 OpenResponse::Folder(folder.map(|p| p.simplified()))
             }
         }
-        #[cfg(mobile)]
+        #[cfg(all(mobile, not(target_os = "ios")))]
         return Err(crate::Error::FolderPickerNotImplemented);
     } else if options.multiple {
         let tauri_scope = window.state::<tauri::scope::Scopes>();

plugins/dialog/src/lib.rs

@@ -506,7 +506,7 @@ impl<R: Runtime> FileDialogBuilder<R> {
     ///     Ok(())
     ///   });
     /// ```
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     pub fn pick_folder<F: FnOnce(Option<FilePath>) + Send + 'static>(self, f: F) {
         pick_folder(self, f)
     }
@@ -528,7 +528,7 @@ impl<R: Runtime> FileDialogBuilder<R> {
     ///     Ok(())
     ///   });
     /// ```
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     pub fn pick_folders<F: FnOnce(Option<Vec<FilePath>>) + Send + 'static>(self, f: F) {
         pick_folders(self, f)
     }
@@ -611,7 +611,7 @@ impl<R: Runtime> FileDialogBuilder<R> {
     ///   // the folder path is `None` if the user closed the dialog
     /// }
     /// ```
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     pub fn blocking_pick_folder(self) -> Option<FilePath> {
         blocking_fn!(self, pick_folder)
     }
@@ -631,7 +631,7 @@ impl<R: Runtime> FileDialogBuilder<R> {
     ///   // the folder paths value is `None` if the user closed the dialog
     /// }
     /// ```
-    #[cfg(desktop)]
+    #[cfg(any(desktop, target_os = "ios"))]
     pub fn blocking_pick_folders(self) -> Option<Vec<FilePath>> {
         blocking_fn!(self, pick_folders)
     }

plugins/dialog/src/mobile.rs

@@ -54,6 +54,11 @@ struct SaveFileResponse {
     file: FilePath,
 }
 
+#[derive(Debug, Deserialize)]
+struct FolderPickerResponse {
+    directories: Vec<FilePath>,
+}
+
 pub fn pick_file<R: Runtime, F: FnOnce(Option<FilePath>) + Send + 'static>(
     dialog: FileDialogBuilder<R>,
     f: F,
@@ -125,3 +130,39 @@ pub fn show_message_dialog<R: Runtime, F: FnOnce(bool) + Send + 'static>(
         f(res.map(|r| r.value).unwrap_or_default())
     });
 }
+
+#[cfg(target_os = "ios")]
+pub fn pick_folders<R: Runtime, F: FnOnce(Option<Vec<FilePath>>) + Send + 'static>(
+    dialog: FileDialogBuilder<R>,
+    f: F,
+) {
+    std::thread::spawn(move || {
+        let res = dialog
+            .dialog
+            .0
+            .run_mobile_plugin::<FolderPickerResponse>("showFolderPicker", dialog.payload(true));
+        if let Ok(response) = res {
+            f(Some(response.directories))
+        } else {
+            f(None)
+        }
+    });
+}
+
+#[cfg(target_os = "ios")]
+pub fn pick_folder<R: Runtime, F: FnOnce(Option<FilePath>) + Send + 'static>(
+    dialog: FileDialogBuilder<R>,
+    f: F,
+) {
+    std::thread::spawn(move || {
+        let res = dialog
+            .dialog
+            .0
+            .run_mobile_plugin::<FolderPickerResponse>("showFolderPicker", dialog.payload(false));
+        if let Ok(response) = res {
+            f(Some(response.directories.into_iter().next().unwrap()))
+        } else {
+            f(None)
+        }
+    });
+}