feature: pickFile() is now implemented for windows

README.md

@@ -872,11 +872,17 @@ For more information read the [Adding an App to an App Group](https://developer.
 ```ts
 function pickFile(options?: PickFileOptionsT): Promise<string[]>;
 ```
-**SUPPORTED**: Android, iOS, macOS. **NOT YET SUPPORTED**: Windows.
+**SUPPORTED**: Android, iOS, macOS, Windows.
 
 Prompts the user to select file(s) using a platform-provided file picker UI,
 which also allows to access files outside the app sandbox.
 
+**BEWARE:** On **windows** the options differ from the other platform since the 
+native file piper doesn't support `mimeTypes` but `fileExtensions` and different
+picker types like `singleFile`, `multipleFIle` and `folder`. For more information
+see [PickFileOptionsT].
+
+
 **BEWARE:** On **macOS (Catalyst)** for this function to work you MUST go to
 _Signing & Capabilities_ settings of your project, and inside its _App Sandbox_
 section to set _File Access_ > _User Selected Files_ to _Read/Write_ value
@@ -1404,14 +1410,25 @@ Type of extra options argument for [mkdir()].
 ```ts
 type PickFileOptionsT = {
   mimeTypes?: string[];
+  pickerType?: 'singleFile' | 'multipleFiles' | 'folder';
+  fileExtensions?: FileExtension[]
 };
 ```
 Optional parameters for [pickFile()] function.
 
-- `mimeTypes` &mdash; **string[]** &mdash; Optional. An array of
+- `mimeTypes` &mdash; **string[]** &mdash; *[Android - iOS - macOS]*  Optional. An array of
   [MIME types](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types)
   of files user is allowed to select. Defaults to `['*/*']` allowing to select
   any file.
+- `pickerType` &mdash; **'singleFile' | 'multipleFiles' | 'folder'** &mdash;  *[Windows]* Optional.
+   The type of objects to pick can be either a single file, multiple files or one folder. 
+   - Multiple folders are not supported by windows.
+   - Defaults to `'singleFile'` */
+- `fileExtensions` &mdash; **FileExtension[]** &mdash; *[Windows]* Optional, The file extensions to pick from. 
+   - Only applies to `pickerType !== 'folder'`
+   - Defaults to `[]` (all file extensions) */
+   - `FileExtension = ´.${string}´` - e.g `'.bmp'`, `'.mp3'`
+
 
 ### ReadDirAssetsResItemT
 [ReadDirAssetsResItemT]: #readdirassetsresitemt

src/NativeReactNativeFs.ts

@@ -4,6 +4,8 @@ import { TurboModuleRegistry } from 'react-native';
 // Note: It would be better to have all these type definitions in a dedicated
 // module, however as of its current version RN's Codegen does not seem to handle
 // type imports correctly.
+// TODO everything needs jsdoc comments. probably the same as in the README.md file. 
+// It's better to read jsdoc through intellisense than to open and find things in the README.md.
 
 export type DownloadBeginCallbackResultT = {
   jobId: number; // The download job ID, required if one wishes to cancel the download. See `stopDownload`.
@@ -40,8 +42,20 @@ export type NativeDownloadFileOptionsT = {
   hasResumableCallback: boolean;
 };
 
+export type FileExtension = `.${string}`;
 export type PickFileOptionsT = {
+  /** **[Android - iOS - macOS]** The mime types that restrict the type of files that can be picked. 
+   * - For more information, see [Common MIME types](https://developer.mozilla.org/en-US/docs/Web/HTTP/MIME_types/Common_types). */
   mimeTypes: string[];
+  /** **[Windows]** 
+   * The type of objects to pick can be either a single file, multiple files or one folder. 
+   * - Multiple folders are not supported by windows.
+   * - Defaults to `'singleFile'` */
+  pickerType: 'singleFile' | 'multipleFiles' | 'folder';
+  /** **[Windows]** The file extensions to pick from. 
+   * - Only applies to `pickerType !== 'folder'`
+   * - Defaults to `[]` (all file extensions) */
+  fileExtensions: FileExtension[]
 };
 
 export type DownloadFileOptionsT = {

src/index.ts

@@ -231,6 +231,8 @@ export function pickFile(
 ): Promise<string[]> {
   return RNFS.pickFile({
     mimeTypes: options.mimeTypes || ['*/*'],
+    pickerType: options.pickerType || 'singleFile',
+    fileExtensions: options.fileExtensions || [],
   });
 }
 

windows/ReactNativeFs/ReactNativeModule.cpp

@@ -16,6 +16,8 @@
 #include <winrt/Windows.Web.Http.Headers.h>
 #include <winrt/Windows.ApplicationModel.h>
 #include <winrt/Windows.Foundation.h>
+#include <winrt/Windows.Storage.Pickers.h>
+#include <winrt/Windows.Storage.AccessCache.h>
 
 #include "RNFSException.h"
 
@@ -24,6 +26,7 @@ using namespace winrt::ReactNativeFs;
 using namespace winrt::Windows::ApplicationModel;
 using namespace winrt::Windows::Storage;
 using namespace winrt::Windows::Storage::Streams;
+using namespace winrt::Windows::Storage::Pickers;
 using namespace winrt::Windows::Foundation;
 using namespace winrt::Windows::Web::Http;
 
@@ -1127,6 +1130,164 @@ IAsyncAction ReactNativeModule::ProcessUploadRequestAsync(ReactPromise<JSValueOb
     }
 }
 
+void ReactNativeModule::pickFile(JSValueObject options, ReactPromise<JSValueArray> promise) noexcept
+{
+    m_reactContext.UIDispatcher().Post([this, options = std::move(options), promise = std::move(promise)]() mutable {
+        try
+        {
+            // read options
+            std::string pickerType = "multipleFiles"; // Default value
+            if (options.find("pickerType") != options.end())
+            {
+                pickerType = options["pickerType"].AsString();
+            }
+
+            std::vector<std::wstring> fileTypes;
+            if (options.find("fileExtensions") != options.end())
+            {
+                for (const auto& mimeType : options["fileExtensions"].AsArray())
+                {
+                    fileTypes.push_back(std::wstring(winrt::to_hstring(mimeType.AsString())));
+                }
+            }
+
+            // folder picker
+            if (pickerType == "folder")
+            {
+                FolderPicker picker;
+                picker.SuggestedStartLocation(PickerLocationId::DocumentsLibrary);
+                picker.FileTypeFilter().Append(L"*");
+
+                picker.PickSingleFolderAsync().Completed([promise = std::move(promise)](IAsyncOperation<StorageFolder> const& operation, AsyncStatus const status) mutable {
+                    try
+                    {
+                        if (status == AsyncStatus::Completed)
+                        {
+                            StorageFolder folder = operation.GetResults();
+                            if (folder)
+                            {
+                                JSValueArray result;
+                                result.push_back(JSValueObject{
+                                    {"name", winrt::to_string(folder.Name())},
+                                    {"path", winrt::to_string(folder.Path())}
+                                });
+                                promise.Resolve(std::move(result));
+                            }
+                            else
+                            {
+                                promise.Reject("No folder was picked.");
+                            }
+                        }
+                        else
+                        {
+                            promise.Reject("Folder picker operation was not completed.");
+                        }
+                    }
+                    catch (const hresult_error& ex)
+                    {
+                        promise.Reject(winrt::to_string(ex.message()).c_str());
+                    }
+                });
+            }
+
+            // file picker
+            else
+            {
+                FileOpenPicker picker;
+                picker.ViewMode(PickerViewMode::Thumbnail);
+                picker.SuggestedStartLocation(PickerLocationId::DocumentsLibrary);
+
+                if (!fileTypes.empty())
+                {
+                    for (const auto& fileType : fileTypes)
+                    {
+                        picker.FileTypeFilter().Append(fileType);
+                    }
+                }
+                else
+                {
+                    picker.FileTypeFilter().Append(L"*");
+                }
+
+                // single files
+                if (pickerType == "singleFile")
+                {
+                    picker.PickSingleFileAsync().Completed([promise = std::move(promise)](IAsyncOperation<StorageFile> const& operation, AsyncStatus const status) mutable {
+                        try
+                        {
+                            if (status == AsyncStatus::Completed)
+                            {
+                                StorageFile file = operation.GetResults();
+                                if (file)
+                                {
+                                    JSValueArray result;
+                                    result.push_back(winrt::to_string(file.Path()));
+                                    promise.Resolve(std::move(result));
+                                }
+                                else
+                                {
+                                    promise.Reject("No file was picked.");
+                                }
+                            }
+                            else
+                            {
+                                promise.Reject("File picker operation was not completed.");
+                            }
+                        }
+                        catch (const hresult_error& ex)
+                        {
+                            promise.Reject(winrt::to_string(ex.message()).c_str());
+                        }
+                    });
+                }
+
+                // multiple files
+                else if (pickerType == "multipleFiles")
+                {
+                    picker.PickMultipleFilesAsync().Completed([promise = std::move(promise)](IAsyncOperation<IVectorView<StorageFile>> const& operation, AsyncStatus const status) mutable {
+                        try
+                        {
+                            if (status == AsyncStatus::Completed)
+                            {
+                                auto files = operation.GetResults();
+                                if (files.Size() > 0)
+                                {
+                                    JSValueArray result;
+                                    for (const auto& file : files)
+                                    {
+                                        result.push_back(winrt::to_string(file.Path()));
+                                    }
+                                    promise.Resolve(std::move(result));
+                                }
+                                else
+                                {
+                                    promise.Reject("No files were picked.");
+                                }
+                            }
+                            else
+                            {
+                                promise.Reject("File picker operation was not completed.");
+                            }
+                        }
+                        catch (const hresult_error& ex)
+                        {
+                            promise.Reject(winrt::to_string(ex.message()).c_str());
+                        }
+                    });
+                }
+                else
+                {
+                    promise.Reject("Invalid pickerType option.");
+                }
+            }
+        }
+        catch (const hresult_error& ex)
+        {
+            promise.Reject(winrt::to_string(ex.message()).c_str());
+        }
+    });
+}
+
 void ReactNativeModule::addListener(std::string eventName) noexcept
 {
     // Keep: Required for RN built in Event Emitter Calls.

windows/ReactNativeFs/ReactNativeModule.h

@@ -167,6 +167,9 @@ struct ReactNativeModule
     REACT_METHOD(removeListeners);
     void removeListeners(int count) noexcept;
 
+    REACT_METHOD(pickFile);
+    void pickFile(JSValueObject options, ReactPromise<JSValueArray> promise) noexcept;
+
 private:
     void splitPath(const std::wstring& fullPath, winrt::hstring& directoryPath, winrt::hstring& fileName) noexcept;