feat(file-system): append, appendText & createFile (#10285)

apps/automated/src/file-system/file-system-tests.ts

@@ -5,7 +5,7 @@ import * as fs from '@nativescript/core/file-system';
 
 import * as TKUnit from '../tk-unit';
 import * as appModule from '@nativescript/core/application';
-import { isIOS, Device, platformNames } from '@nativescript/core';
+import { isIOS, Device, platformNames, isAndroid } from '@nativescript/core';
 
 export var testPathNormalize = function () {
 	// >> file-system-normalize
@@ -719,3 +719,62 @@ export function test_FileCopy(done) {
 		.then(() => done())
 		.catch(done);
 }
+
+export function testAndroidCreate() {
+	let testFunc = function testFunc() {
+		const file = fs.File.android.createFile({
+			directory: fs.AndroidDirectory.DOWNLOADS,
+			name: `${Date.now()}.txt`,
+			mime: 'text/plain',
+			relativePath: `NativeScript`,
+		});
+
+		file.writeTextSync('some text');
+
+		return file;
+	};
+	if (isAndroid) {
+		const file = testFunc();
+		TKUnit.assertEqual(file.readTextSync(), 'some text', `The contents of the new file created in the 'AndroidDirectory.DOWNLOADS' folder are not as expected.`);
+		file.removeSync();
+		TKUnit.assertTrue(!fs.File.exists(file.path));
+	} else {
+		TKUnit.assertThrows(testFunc, `Trying to retrieve createFile on a platform different from Android should throw!`, `createFile is available on Android only!`);
+	}
+}
+
+export function test_FileAppend(done) {
+	const content = 'Hello World';
+	const hello_world = global.isIOS ? NSString.stringWithString(content).dataUsingEncoding(NSUTF8StringEncoding) : new java.lang.String(content).getBytes('UTF-8');
+	const file = fs.File.fromPath(fs.path.join(fs.knownFolders.temp().path, `${Date.now()}-app.txt`));
+	file
+		.appendText('Hello')
+		.then(() => file.appendText(' World'))
+		.then(() => {
+			TKUnit.assert(file.size === hello_world.length);
+			return file.readText();
+		})
+		.then((value) => {
+			TKUnit.assert(value === content);
+
+			return Promise.allSettled([file.remove()]);
+		})
+		.then(() => done())
+		.catch(done);
+}
+
+export function test_FileAppendText(done) {
+	const content = 'Hello World';
+	const file = fs.File.fromPath(fs.path.join(fs.knownFolders.temp().path, `${Date.now()}-app.txt`));
+	file
+		.appendText('Hello')
+		.then(() => file.appendText(' World'))
+		.then(() => file.readText())
+		.then((value) => {
+			TKUnit.assert(value === content);
+
+			return Promise.allSettled([file.remove()]);
+		})
+		.then(() => done())
+		.catch(done);
+}

apps/toolbox/src/pages/fs-helper.ts

@@ -1,4 +1,4 @@
-import { Page, EventData, Application, File, Folder, knownFolders, path, getFileAccess, Utils } from '@nativescript/core';
+import { Page, EventData, Application, File, Folder, knownFolders, path, getFileAccess, Utils, Screen, Http, AndroidDirectory, ImageSource, alert } from '@nativescript/core';
 
 let page: Page;
 
@@ -217,3 +217,103 @@ function getFileNameFromContent(content: string) {
 	const file = getFileAccess().getFile(content);
 	return decodeURIComponent(file.name).split('/').pop().toLowerCase();
 }
+
+let lastDownload: File;
+export function createFileInDownloads() {
+	if (!global.isAndroid) {
+		return;
+	}
+	const width = Screen.mainScreen.widthPixels;
+	const height = Screen.mainScreen.heightPixels;
+	const randomImageUrl = `https://picsum.photos/${width}/${height}.jpg?random=${Date.now()}`;
+
+	Http.getFile(randomImageUrl).then((result: File) => {
+		let file = File.android.createFile({
+			directory: AndroidDirectory.DOWNLOADS,
+			name: `${Date.now()}.jpg`,
+			mime: 'image/jpeg',
+			relativePath: `NativeScript`,
+		});
+		result
+			.copy(file.path)
+			.then((done) => {
+				lastDownload = file;
+				console.log('done: ' + done + '\n' + 'Original path: ' + result.path + '\n' + 'Copied to: ' + file.path + '\n' + 'Original size: ' + result.size + '\n' + 'Copy size: ' + file.size + '\n');
+				alert(`File saved in ${AndroidDirectory.DOWNLOADS}/NativeScript`);
+			})
+			.catch((error) => {
+				console.error(error);
+			});
+	});
+}
+
+export function createFileInGallery() {
+	if (!global.isAndroid) {
+		return;
+	}
+	const width = Screen.mainScreen.widthPixels;
+	const height = Screen.mainScreen.heightPixels;
+	const randomImageUrl = `https://picsum.photos/${width}/${height}.jpg?random=${Date.now()}`;
+
+	Http.getFile(randomImageUrl).then((result: File) => {
+		let file = File.android.createFile({
+			directory: AndroidDirectory.PICTURES,
+			name: `${Date.now()}.jpg`,
+			mime: 'image/jpeg',
+			relativePath: `NativeScript`,
+		});
+		result
+			.copy(file.path)
+			.then((done) => {
+				console.log('done: ' + done + '\n' + 'Original path: ' + result + '\n' + 'Copied to: ' + file.path + '\n' + 'Original size: ' + result.size + '\n' + 'Copy size: ' + file.size + '\n');
+				alert(`File saved in ${AndroidDirectory.PICTURES}/NativeScript`);
+			})
+			.catch((error) => {
+				console.error(error);
+			});
+	});
+}
+
+export function createFileInMusic() {
+	if (!global.isAndroid) {
+		return;
+	}
+
+	Http.getFile('https://github.com/rafaelreis-hotmart/Audio-Sample-files/raw/master/sample.mp3').then((result: File) => {
+		let file = File.android.createFile({
+			directory: AndroidDirectory.MUSIC,
+			name: `${Date.now()}.MP3`,
+			mime: 'audio/mp3',
+			relativePath: `NativeScript/MP3`,
+		});
+
+		result
+			.copy(file.path)
+			.then((done) => {
+				console.log('done: ' + done + '\n' + 'Original path: ' + result + '\n' + 'Copied to: ' + file.path + '\n' + 'Original size: ' + result.size + '\n' + 'Copy size: ' + file.size + '\n');
+
+				alert(`File saved in ${AndroidDirectory.MUSIC}/NativeScript/MP3`);
+			})
+			.catch((error) => {
+				console.error(error);
+			});
+	});
+}
+
+export function createAndAppendText() {
+	const file = File.fromPath(path.join(knownFolders.temp().path, `${Date.now()}-app.txt`));
+	file.appendTextSync('Hello');
+	file.appendTextSync(' World');
+	const data = file.readTextSync();
+	console.log('createAndAppend:', data === 'Hello World');
+}
+
+export function createAndAppendData() {
+	const file = File.fromPath(path.join(knownFolders.temp().path, `${Date.now()}-app.txt`));
+	const hello = global.isIOS ? NSString.stringWithString('Hello').dataUsingEncoding(NSUTF8StringEncoding) : new java.lang.String('Hello').getBytes('UTF-8');
+	const world = global.isIOS ? NSString.stringWithString(' World').dataUsingEncoding(NSUTF8StringEncoding) : new java.lang.String(' World').getBytes('UTF-8');
+	file.appendSync(hello);
+	file.appendSync(world);
+	const data = file.readTextSync();
+	console.log('createAndAppendData:', data === 'Hello World');
+}

apps/toolbox/src/pages/fs-helper.xml

@@ -5,5 +5,10 @@
             <Button text="Pick File" tap="pickFile" />
             <Button text="Pick Multiple Files" tap="pickFiles" />
             <Button text="Test Copy" tap="copyTest" />
+            <Button text="External File Creation" tap="createFileInDownloads" />
+            <Button text="Add file to gallery" tap="createFileInGallery" />
+            <Button text="Add file to music" tap="createFileInMusic" />
+            <Button text="Append Text" tap="createAndAppendText" />
+            <Button text="Append Data" tap="createAndAppendData" />
     </StackLayout>
 </Page>

packages/core/file-system/file-system-access.android.ts

@@ -375,6 +375,81 @@ export class FileSystemAccess implements IFileSystemAccess {
 		}
 	}
 
+	public appendBuffer = this.appendBufferSync.bind(this);
+
+	public appendBufferAsync(path: string, buffer: ArrayBuffer | Uint8Array | Uint8ClampedArray): Promise<void> {
+		return new Promise<void>((resolve, reject) => {
+			try {
+				org.nativescript.widgets.Async.File.appendBuffer(
+					path,
+					FileSystemAccess.getBuffer(buffer),
+					new org.nativescript.widgets.Async.CompleteCallback({
+						onComplete: () => {
+							resolve();
+						},
+						onError: (err) => {
+							reject(new Error(err));
+						},
+					}),
+					null
+				);
+			} catch (ex) {
+				reject(ex);
+			}
+		});
+	}
+
+	public appendBufferSync(path: string, buffer: ArrayBuffer | Uint8Array | Uint8ClampedArray, onError?: (error: any) => any) {
+		try {
+			const javaFile = new java.io.File(path);
+			const stream = new java.io.FileOutputStream(javaFile);
+			const channel = stream.getChannel();
+			channel.write(FileSystemAccess.getBuffer(buffer));
+			stream.close();
+		} catch (exception) {
+			if (onError) {
+				onError(exception);
+			}
+		}
+	}
+
+	public append = this.appendSync.bind(this);
+
+	public appendAsync(path: string, bytes: androidNative.Array<number>): Promise<void> {
+		return new Promise<void>((resolve, reject) => {
+			try {
+				org.nativescript.widgets.Async.File.append(
+					path,
+					bytes,
+					new org.nativescript.widgets.Async.CompleteCallback({
+						onComplete: () => {
+							resolve();
+						},
+						onError: (err) => {
+							reject(new Error(err));
+						},
+					}),
+					null
+				);
+			} catch (ex) {
+				reject(ex);
+			}
+		});
+	}
+
+	public appendSync(path: string, bytes: androidNative.Array<number>, onError?: (error: any) => any) {
+		try {
+			const javaFile = new java.io.File(path);
+			const stream = new java.io.FileOutputStream(javaFile, true);
+			stream.write(bytes, 0, bytes.length);
+			stream.close();
+		} catch (exception) {
+			if (onError) {
+				onError(exception);
+			}
+		}
+	}
+
 	public writeBuffer = this.writeBufferSync.bind(this);
 
 	public writeBufferAsync(path: string, buffer: ArrayBuffer | Uint8Array | Uint8ClampedArray): Promise<void> {
@@ -538,6 +613,56 @@ export class FileSystemAccess implements IFileSystemAccess {
 		return s;
 	}
 
+	public appendText = this.appendTextSync.bind(this);
+
+	public appendTextAsync(path: string, content: string, encoding?: any): Promise<void> {
+		let actualEncoding = encoding;
+		if (!actualEncoding) {
+			actualEncoding = textModule.encoding.UTF_8;
+		}
+
+		return new Promise<void>((resolve, reject) => {
+			try {
+				org.nativescript.widgets.Async.File.appendText(
+					path,
+					content,
+					actualEncoding,
+					new org.nativescript.widgets.Async.CompleteCallback({
+						onComplete: () => {
+							resolve();
+						},
+						onError: (err) => {
+							reject(new Error(err));
+						},
+					}),
+					null
+				);
+			} catch (ex) {
+				reject(ex);
+			}
+		});
+	}
+
+	public appendTextSync(path: string, content: string, onError?: (error: any) => any, encoding?: any) {
+		try {
+			const javaFile = new java.io.File(path);
+			const stream = new java.io.FileOutputStream(javaFile, true);
+
+			let actualEncoding = encoding;
+			if (!actualEncoding) {
+				actualEncoding = textModule.encoding.UTF_8;
+			}
+			const writer = new java.io.OutputStreamWriter(stream, actualEncoding);
+
+			writer.write(content);
+			writer.close();
+		} catch (exception) {
+			if (onError) {
+				onError(exception);
+			}
+		}
+	}
+
 	public writeText = this.writeTextSync.bind(this);
 
 	public writeTextAsync(path: string, content: string, encoding?: any): Promise<void> {
@@ -879,6 +1004,124 @@ export class FileSystemAccess29 extends FileSystemAccess {
 		return super.getCurrentAppPath();
 	}
 
+	appendBuffer = this.appendBufferSync.bind(this);
+
+	appendBufferAsync(path: string, content: any): Promise<void> {
+		if (isContentUri(path)) {
+			return new Promise<void>((resolve, reject) => {
+				getOrSetHelper(path).appendBuffer(
+					applicationContext,
+					FileSystemAccess.getBuffer(content),
+					new org.nativescript.widgets.FileHelper.Callback({
+						onSuccess(result) {
+							resolve();
+						},
+						onError(error) {
+							reject(error);
+						},
+					})
+				);
+			});
+		}
+		return super.appendAsync(path, content);
+	}
+
+	appendBufferSync(path: string, content: any, onError?: (error: any) => any) {
+		if (isContentUri(path)) {
+			let callback = null;
+			if (typeof onError === 'function') {
+				callback = new org.nativescript.widgets.FileHelper.Callback({
+					onSuccess(result) {},
+					onError(error) {
+						onError(error);
+					},
+				});
+			}
+			getOrSetHelper(path).appendSync(applicationContext, FileSystemAccess.getBuffer(content), callback);
+		} else {
+			super.appendSync(path, content, onError);
+		}
+	}
+
+	append = this.appendSync.bind(this);
+
+	appendAsync(path: string, content: any): Promise<void> {
+		if (isContentUri(path)) {
+			return new Promise<void>((resolve, reject) => {
+				getOrSetHelper(path).append(
+					applicationContext,
+					content,
+					new org.nativescript.widgets.FileHelper.Callback({
+						onSuccess(result) {
+							resolve();
+						},
+						onError(error) {
+							reject(error);
+						},
+					})
+				);
+			});
+		}
+		return super.appendAsync(path, content);
+	}
+
+	appendSync(path: string, content: any, onError?: (error: any) => any) {
+		if (isContentUri(path)) {
+			let callback = null;
+			if (typeof onError === 'function') {
+				callback = new org.nativescript.widgets.FileHelper.Callback({
+					onSuccess(result) {},
+					onError(error) {
+						onError(error);
+					},
+				});
+			}
+			getOrSetHelper(path).appendSync(applicationContext, content, callback);
+		} else {
+			super.appendSync(path, content, onError);
+		}
+	}
+
+	appendText = this.appendTextSync.bind(this);
+
+	appendTextAsync(path: string, content: string, encoding?: any): Promise<void> {
+		if (isContentUri(path)) {
+			return new Promise<void>((resolve, reject) => {
+				getOrSetHelper(path).appendText(
+					applicationContext,
+					content,
+					encoding ?? null,
+					new org.nativescript.widgets.FileHelper.Callback({
+						onSuccess(result) {
+							resolve();
+						},
+						onError(error) {
+							reject(error);
+						},
+					})
+				);
+			});
+		}
+		return super.appendTextAsync(path, content, encoding);
+	}
+
+	appendTextSync(path: string, content: string, onError?: (error: any) => any, encoding?: any) {
+		if (isContentUri(path)) {
+			let callback = null;
+			if (typeof onError === 'function') {
+				callback = new org.nativescript.widgets.FileHelper.Callback({
+					onSuccess(result) {},
+					onError(error) {
+						onError(error);
+					},
+				});
+			}
+			getOrSetHelper(path).appendTextSync(applicationContext, content, encoding ?? null, callback);
+		} else {
+			super.appendTextSync(path, content, onError);
+		}
+	}
+
 	public readText = this.readTextSync.bind(this);
 
 	readTextAsync(path: string, encoding?: any): Promise<string> {

packages/core/file-system/file-system-access.d.ts

@@ -2,6 +2,55 @@
  * An utility class used to provide methods to access and work with the file system.
  */
 export interface IFileSystemAccess {
+	/**
+	 * Appends binary to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 * @param onError (optional) A callback function to use if any error occurs.
+	 */
+	append(path: string, content: any, onError?: (error: any) => any);
+
+	/**
+	 * Appends binary to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 */
+	appendAsync(path: string, content: any): Promise<void>;
+
+	/**
+	 * Appends a binary to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 * @param onError (optional) A callback function to use if any error occurs.
+	 */
+	appendSync(path: string, content: any, onError?: (error: any) => any);
+
+	/**
+	 * Appends text to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 * @param onError (optional) A callback function to use if any error occurs.
+	 * @param encoding (optional) If set writes the text with the specified encoding (default UTF-8).
+	 */
+	appendText(path: string, content: string, onError?: (error: any) => any, encoding?: any);
+
+	/**
+	 * Appends text to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 * @param encoding (optional) If set writes the text with the specified encoding (default UTF-8).
+	 */
+	appendTextAsync(path: string, content: string, encoding?: any): Promise<void>;
+
+	/**
+	 * Appends text to a file with a given path.
+	 * @param path The path to the source file.
+	 * @param content The content which will be written to the file.
+	 * @param onError (optional) A callback function to use if any error occurs.
+	 * @param encoding (optional) If set writes the text with the specified encoding (default UTF-8).
+	 */
+	appendTextSync(path: string, content: string, onError?: (error: any) => any, encoding?: any);
+
 	/**
 	 * Copies a file to a given path.
 	 * @param src The path to the source file.
@@ -282,6 +331,24 @@ export interface IFileSystemAccess {
 }
 
 export class FileSystemAccess implements IFileSystemAccess {
+	appendBuffer(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray, onError?: (error: any) => any);
+
+	appendBufferAsync(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray): Promise<void>;
+
+	appendBufferSync(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray, onError?: (error: any) => any);
+
+	append(path: string, content: any, onError?: (error: any) => any);
+
+	appendAsync(path: string, content: any): Promise<void>;
+
+	appendSync(path: string, content: any, onError?: (error: any) => any);
+
+	appendText(path: string, content: string, onError?: (error: any) => any, encoding?: any);
+
+	appendTextAsync(path: string, content: string, encoding?: any): Promise<void>;
+
+	appendTextSync(path: string, content: string, onError?: (error: any) => any, encoding?: any);
+
 	copy(src: string, dest: string, onError?: (error: any) => any): boolean;
 
 	copySync(src: string, dest: string, onError?: (error: any) => any): boolean;

packages/core/file-system/file-system-access.ios.ts

@@ -445,6 +445,115 @@ export class FileSystemAccess {
 		}
 	}
 
+	public appendBuffer = this.appendBufferSync.bind(this);
+
+	public appendBufferAsync(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray): Promise<void> {
+		return new Promise<void>((resolve, reject) => {
+			try {
+				const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+				(handle as any).appendDataCompletion(FileSystemAccess.getBuffer(content), (error) => {
+					if (error) {
+						reject(error);
+					} else {
+						resolve();
+					}
+					handle.closeFile();
+				});
+			} catch (ex) {
+				reject(new Error("Failed to write file at path '" + path + "': " + ex));
+			}
+		});
+	}
+
+	public appendBufferSync(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray, onError?: (error: any) => any) {
+		try {
+			const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+			handle.seekToEndOfFile();
+			handle.writeData(FileSystemAccess.getBuffer(content));
+			handle.closeFile();
+		} catch (ex) {
+			if (onError) {
+				onError(new Error("Failed to write to file '" + path + "': " + ex));
+			}
+		}
+	}
+
+	public append = this.appendSync.bind(this);
+
+	public appendAsync(path: string, content: NSData): Promise<void> {
+		return new Promise<void>((resolve, reject) => {
+			try {
+				const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+				(handle as any).appendDataCompletion(content, (error) => {
+					if (error) {
+						reject(error);
+					} else {
+						resolve();
+					}
+					handle.closeFile();
+				});
+			} catch (ex) {
+				reject(new Error("Failed to write file at path '" + path + "': " + ex));
+			}
+		});
+	}
+
+	public appendSync(path: string, content: NSData, onError?: (error: any) => any) {
+		try {
+			const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+			handle.seekToEndOfFile();
+			handle.writeData(content);
+			handle.closeFile();
+		} catch (ex) {
+			if (onError) {
+				onError(new Error("Failed to write to file '" + path + "': " + ex));
+			}
+		}
+	}
+
+	public appendText = this.appendTextSync.bind(this);
+
+	public appendTextAsync(path: string, content: string, encoding?: any): Promise<void> {
+		const nsString = NSString.stringWithString(content);
+		const actualEncoding = encoding || textEncoding.UTF_8;
+
+		return new Promise<void>((resolve, reject) => {
+			try {
+				const data = nsString.dataUsingEncoding(actualEncoding);
+				const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+				(handle as any).appendDataCompletion(data, (error) => {
+					if (error) {
+						reject(error);
+					} else {
+						resolve();
+					}
+					handle.closeFile();
+				});
+			} catch (ex) {
+				reject(new Error("Failed to append file at path '" + path + "': " + ex));
+			}
+		});
+	}
+
+	public appendTextSync(path: string, content: string, onError?: (error: any) => any, encoding?: any) {
+		const nsString = NSString.stringWithString(content);
+
+		const actualEncoding = encoding || textEncoding.UTF_8;
+
+		// TODO: verify the useAuxiliaryFile parameter should be false
+		try {
+			const data = nsString.dataUsingEncoding(actualEncoding);
+			const handle = NSFileHandle.fileHandleForWritingAtPath(path);
+			handle.seekToEndOfFile();
+			handle.writeData(data);
+			handle.closeFile();
+		} catch (ex) {
+			if (onError) {
+				onError(new Error("Failed to append to file '" + path + "': " + ex));
+			}
+		}
+	}
+
 	public writeBuffer = this.writeBufferSync.bind(this);
 
 	public writeBufferAsync(path: string, content: ArrayBuffer | Uint8Array | Uint8ClampedArray): Promise<void> {

packages/core/file-system/index.d.ts

@@ -1,5 +1,20 @@
 import { FileSystemAccess } from './file-system-access';
 
+export enum AndroidDirectory {
+	ALARMS,
+	AUDIOBOOKS,
+	DCIM,
+	DOCUMENTS,
+	DOWNLOADS,
+	MOVIES,
+	MUSIC,
+	NOTIFICATIONS,
+	PICTURES,
+	PODCASTS,
+	RINGTONES,
+	SCREENSHOTS,
+}
+
 /**
  * Returns FileSystemAccess, a shared singleton utility class to provide methods to access and work with the file system. This is used under the hood of all the file system apis in @nativescript/core and provided as a lower level convenience if needed.
  * @returns FileSystemAccess
@@ -55,10 +70,27 @@ export class FileSystemEntity {
 	renameSync(newName: string, onError?: (error: any) => any): void;
 }
 
+/**
+ * Contains Android-specific the file system helpers.
+ */
+class Android {
+	createFile(options: { relativePath?: string; name: string; mime: string; directory: AndroidDirectory }): File;
+}
+
+/**
+ * Contains iOS-specific the file system helpers.
+ */
+
+class iOS {}
+
 /**
  * Represents a File entity on the file system.
  */
 export class File extends FileSystemEntity {
+	static readonly android: Android;
+
+	static readonly ios: iOS;
+
 	/**
 	 * Checks whether a File with the specified path already exists.
 	 * @param path The path to check for.
@@ -80,6 +112,34 @@ export class File extends FileSystemEntity {
 	 */
 	isLocked: boolean;
 
+	/**
+	 * Appends the provided string to the file, using the specified encoding (defaults to UTF-8).
+	 * @param content The content to be saved to the file.
+	 * @param encoding An optional value specifying the preferred encoding (defaults to UTF-8).
+	 */
+	appendText(content: string, encoding?: string): Promise<any>;
+
+	/**
+	 * Appends the provided string to the file synchronously, using the specified encoding (defaults to UTF-8).
+	 * @param content The content to be saved to the file.
+	 * @param onError An optional function to be called if some IO-error occurs.
+	 * @param encoding An optional value specifying the preferred encoding (defaults to UTF-8).
+	 */
+	appendTextSync(content: string, onError?: (error: any) => any, encoding?: string): void;
+
+	/**
+	 * Appends the provided binary content to the file.
+	 * @param content The binary content to be saved to the file.
+	 */
+	append(content: any): Promise<void>;
+
+	/**
+	 * Appends the provided binary content to the file synchronously.
+	 * @param content The binary content to be saved to the file.
+	 * @param onError An optional function to be called if some IO-error occurs.
+	 */
+	appendSync(content: any, onError?: (error: any) => any): void;
+
 	/**
 	 * Copies a file to a given path.
 	 * @param dest The path to the destination file.

packages/core/file-system/index.ts

@@ -190,7 +190,136 @@ function getApplicationContext() {
 	return applicationContext;
 }
 
+export enum AndroidDirectory {
+	ALARMS = 'alarms',
+	AUDIOBOOKS = 'audiobooks',
+	DCIM = 'dcim',
+	DOCUMENTS = 'documents',
+	DOWNLOADS = 'downloads',
+	MOVIES = 'movies',
+	MUSIC = 'music',
+	NOTIFICATIONS = 'notifications',
+	PICTURES = 'pictures',
+	PODCASTS = 'podcasts',
+	RINGTONES = 'ringtones',
+	SCREENSHOTS = 'screenshots',
+}
+
+function getAndroidDirectory(value: AndroidDirectory): { path: string; column: android.net.Uri } | null {
+	switch (value) {
+		case AndroidDirectory.ALARMS:
+			return {
+				path: android.os.Environment.DIRECTORY_ALARMS,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.AUDIOBOOKS:
+			return {
+				path: android.os.Environment.DIRECTORY_AUDIOBOOKS,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.DCIM:
+			return {
+				path: android.os.Environment.DIRECTORY_DCIM,
+				column: android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.DOCUMENTS:
+			return {
+				path: android.os.Environment.DIRECTORY_DOCUMENTS,
+				column: android.provider.MediaStore.Files.getContentUri('external'),
+			};
+		case AndroidDirectory.DOWNLOADS:
+			return {
+				path: android.os.Environment.DIRECTORY_DOWNLOADS,
+				column: android.provider.MediaStore.Downloads.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.MOVIES:
+			return {
+				path: android.os.Environment.DIRECTORY_MOVIES,
+				column: android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.MUSIC:
+			return {
+				path: android.os.Environment.DIRECTORY_MUSIC,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.NOTIFICATIONS:
+			return {
+				path: android.os.Environment.DIRECTORY_NOTIFICATIONS,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.PICTURES:
+			return {
+				path: android.os.Environment.DIRECTORY_PICTURES,
+				column: android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.PODCASTS:
+			return {
+				path: android.os.Environment.DIRECTORY_PODCASTS,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.RINGTONES:
+			return {
+				path: android.os.Environment.DIRECTORY_RINGTONES,
+				column: android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+			};
+		case AndroidDirectory.SCREENSHOTS:
+			return {
+				path: android.os.Environment.DIRECTORY_SCREENSHOTS,
+				column: android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+			};
+		default:
+			return null;
+	}
+}
+
+class Android {
+	createFile(options: { relativePath?: string; name: string; mime: string; directory: AndroidDirectory }): File {
+		if (!global.isAndroid) {
+			throw new Error(`createFile is available on Android only!`);
+		}
+
+		const context = getApplicationContext() as android.content.Context;
+
+		const meta = new android.content.ContentValues();
+		meta.put(android.provider.MediaStore.MediaColumns.DISPLAY_NAME, options.name);
+		meta.put(android.provider.MediaStore.MediaColumns.MIME_TYPE, options.mime);
+		//meta.put(android.provider.MediaStore.MediaColumns.DATE_ADDED, java.lang.System.currentTimeMillis() as any);
+
+		const externalDirectory = getAndroidDirectory(options.directory);
+
+		if (SDK_VERSION >= 29) {
+			const relativePath = options?.relativePath ? `/${options.relativePath}` : '';
+			meta.put(android.provider.MediaStore.MediaColumns.RELATIVE_PATH, `${externalDirectory.path}${relativePath}`);
+			// todo
+			//	meta.put(android.provider.MediaStore.MediaColumns.IS_PENDING, java.lang.Integer.valueOf(1));
+		} else {
+			const relativePath = options?.relativePath ? `${options.relativePath}/` : '';
+			const directory = android.os.Environment.getExternalStoragePublicDirectory(externalDirectory.path);
+			const file = new java.io.File(directory, `${relativePath}${options.name}`);
+			meta.put(android.provider.MediaStore.MediaColumns.DATA, file.getAbsolutePath());
+		}
+
+		const uri = context.getContentResolver().insert(externalDirectory.column, meta);
+
+		return File.fromPath(uri.toString());
+	}
+}
+
+const ad = new Android();
+
+class iOS {}
+
+const ios = new iOS();
+
 export class File extends FileSystemEntity {
+	public static get ios() {
+		return ios;
+	}
+
+	public static get android() {
+		return ad;
+	}
+
 	public static fromPath(path: string, copy: boolean = false) {
 		const onError = function (error) {
 			throw error;
@@ -239,6 +368,100 @@ export class File extends FileSystemEntity {
 		return getFileAccess().getFileSize(this.path);
 	}
 
+	public append(content: any): Promise<void> {
+		return new Promise<void>((resolve, reject) => {
+			try {
+				this._checkAccess();
+			} catch (ex) {
+				reject(ex);
+
+				return;
+			}
+
+			this._locked = true;
+
+			getFileAccess()
+				.appendAsync(this.path, content)
+				.then(
+					() => {
+						resolve();
+						this._locked = false;
+					},
+					(error) => {
+						reject(error);
+						this._locked = false;
+					}
+				);
+		});
+	}
+
+	public appendSync(content: any, onError?: (error: any) => any): void {
+		this._checkAccess();
+
+		try {
+			this._locked = true;
+
+			const that = this;
+			const localError = function (error) {
+				that._locked = false;
+				if (onError) {
+					onError(error);
+				}
+			};
+
+			getFileAccess().appendSync(this.path, content, localError);
+		} finally {
+			this._locked = false;
+		}
+	}
+
+	public appendText(content: string, encoding?: string): Promise<any> {
+		return new Promise((resolve, reject) => {
+			try {
+				this._checkAccess();
+			} catch (ex) {
+				reject(ex);
+
+				return;
+			}
+
+			this._locked = true;
+
+			getFileAccess()
+				.appendTextAsync(this.path, content, encoding)
+				.then(
+					() => {
+						resolve(true);
+						this._locked = false;
+					},
+					(error) => {
+						reject(error);
+						this._locked = false;
+					}
+				);
+		});
+	}
+
+	public appendTextSync(content: string, onError?: (error: any) => any, encoding?: string): void {
+		this._checkAccess();
+
+		try {
+			this._locked = true;
+
+			const that = this;
+			const localError = function (error) {
+				that._locked = false;
+				if (onError) {
+					onError(error);
+				}
+			};
+
+			getFileAccess().appendTextSync(this.path, content, localError, encoding);
+		} finally {
+			this._locked = false;
+		}
+	}
+
 	public copy(dest: string): Promise<boolean> {
 		return new Promise<boolean>((resolve, reject) => {
 			try {

packages/core/index.d.ts

@@ -85,7 +85,7 @@ export { Observable, WrappedValue, fromObject, fromObjectRecursive } from './dat
 export type { PropertyChangeData, EventData } from './data/observable';
 export { VirtualArray } from './data/virtual-array';
 export type { ItemsLoading } from './data/virtual-array';
-export { File, FileSystemEntity, Folder, knownFolders, path, getFileAccess } from './file-system';
+export { File, FileSystemEntity, Folder, knownFolders, path, getFileAccess, AndroidDirectory } from './file-system';
 export type { HttpRequestOptions, HttpResponse, Headers, HttpResponseEncoding, HttpContent } from './http';
 import { getFile, getImage, getJSON, getString as httpGetString } from './http';
 export declare const Http: {

packages/core/index.ts

@@ -105,7 +105,7 @@ export { Observable, WrappedValue, fromObject, fromObjectRecursive } from './dat
 export type { PropertyChangeData, EventData } from './data/observable';
 export { VirtualArray } from './data/virtual-array';
 export type { ItemsLoading } from './data/virtual-array';
-export { File, FileSystemEntity, Folder, knownFolders, path, getFileAccess } from './file-system';
+export { File, FileSystemEntity, Folder, knownFolders, path, getFileAccess, AndroidDirectory } from './file-system';
 
 // Export all interfaces from "http" module
 export type { HttpRequestOptions, HttpResponse, Headers, HttpResponseEncoding, HttpContent } from './http';

packages/core/platforms/ios/TNSWidgets.xcframework/Info.plist

@@ -4,6 +4,23 @@
 <dict>
 	<key>AvailableLibraries</key>
 	<array>
+		<dict>
+			<key>DebugSymbolsPath</key>
+			<string>dSYMs</string>
+			<key>LibraryIdentifier</key>
+			<string>ios-arm64_x86_64-maccatalyst</string>
+			<key>LibraryPath</key>
+			<string>TNSWidgets.framework</string>
+			<key>SupportedArchitectures</key>
+			<array>
+				<string>arm64</string>
+				<string>x86_64</string>
+			</array>
+			<key>SupportedPlatform</key>
+			<string>ios</string>
+			<key>SupportedPlatformVariant</key>
+			<string>maccatalyst</string>
+		</dict>
 		<dict>
 			<key>DebugSymbolsPath</key>
 			<string>dSYMs</string>
@@ -35,23 +52,6 @@
 			<key>SupportedPlatformVariant</key>
 			<string>simulator</string>
 		</dict>
-		<dict>
-			<key>DebugSymbolsPath</key>
-			<string>dSYMs</string>
-			<key>LibraryIdentifier</key>
-			<string>ios-arm64_x86_64-maccatalyst</string>
-			<key>LibraryPath</key>
-			<string>TNSWidgets.framework</string>
-			<key>SupportedArchitectures</key>
-			<array>
-				<string>arm64</string>
-				<string>x86_64</string>
-			</array>
-			<key>SupportedPlatform</key>
-			<string>ios</string>
-			<key>SupportedPlatformVariant</key>
-			<string>maccatalyst</string>
-		</dict>
 	</array>
 	<key>CFBundlePackageType</key>
 	<string>XFWK</string>

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64/TNSWidgets.framework/Headers/NSFileHandle+Async.h

@@ -0,0 +1,22 @@
+//
+//  NSFileHandle+Async.h
+//  TNSWidgets
+//
+//  Created by Osei Fortune on 03/05/2023.
+//  Copyright © 2023 Telerik A D. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSFileHandle (Async)
+
+- (void)appendData:(nonnull NSData*) data
+         completion:(void (^) (NSError*))callback;
+
++ (void)fileHandleWith:(NSString *)path data:(NSData *)data completion:(void (^)(NSFileHandle*,NSError*))callback;
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64/TNSWidgets.framework/Headers/TNSWidgets.h

@@ -22,3 +22,4 @@ FOUNDATION_EXPORT const unsigned char TNSWidgetsVersionString[];
 #import "TNSProcess.h"
 #import "NSString+Async.h"
 #import "NSData+Async.h"
+#import "NSFileHandle+Async.h"

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-maccatalyst/TNSWidgets.framework/Versions/A/Headers/NSFileHandle+Async.h

@@ -0,0 +1,22 @@
+//
+//  NSFileHandle+Async.h
+//  TNSWidgets
+//
+//  Created by Osei Fortune on 03/05/2023.
+//  Copyright © 2023 Telerik A D. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSFileHandle (Async)
+
+- (void)appendData:(nonnull NSData*) data
+         completion:(void (^) (NSError*))callback;
+
++ (void)fileHandleWith:(NSString *)path data:(NSData *)data completion:(void (^)(NSFileHandle*,NSError*))callback;
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-maccatalyst/TNSWidgets.framework/Versions/A/Headers/TNSWidgets.h

@@ -22,3 +22,4 @@ FOUNDATION_EXPORT const unsigned char TNSWidgetsVersionString[];
 #import "TNSProcess.h"
 #import "NSString+Async.h"
 #import "NSData+Async.h"
+#import "NSFileHandle+Async.h"

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-maccatalyst/TNSWidgets.framework/Versions/A/Resources/Info.plist

@@ -3,7 +3,7 @@
 <plist version="1.0">
 <dict>
 	<key>BuildMachineOSBuild</key>
-	<string>21G72</string>
+	<string>22D68</string>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>en</string>
 	<key>CFBundleExecutable</key>
@@ -29,7 +29,7 @@
 	<key>DTCompiler</key>
 	<string>com.apple.compilers.llvm.clang.1_0</string>
 	<key>DTPlatformBuild</key>
-	<string>13F100</string>
+	<string>14A309</string>
 	<key>DTPlatformName</key>
 	<string>macosx</string>
 	<key>DTPlatformVersion</key>
@@ -39,9 +39,9 @@
 	<key>DTSDKName</key>
 	<string>macosx12.3</string>
 	<key>DTXcode</key>
-	<string>1341</string>
+	<string>1400</string>
 	<key>DTXcodeBuild</key>
-	<string>13F100</string>
+	<string>14A309</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>10.15</string>
 	<key>UIDeviceFamily</key>

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-simulator/TNSWidgets.framework/Headers/NSFileHandle+Async.h

@@ -0,0 +1,22 @@
+//
+//  NSFileHandle+Async.h
+//  TNSWidgets
+//
+//  Created by Osei Fortune on 03/05/2023.
+//  Copyright © 2023 Telerik A D. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSFileHandle (Async)
+
+- (void)appendData:(nonnull NSData*) data
+         completion:(void (^) (NSError*))callback;
+
++ (void)fileHandleWith:(NSString *)path data:(NSData *)data completion:(void (^)(NSFileHandle*,NSError*))callback;
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-simulator/TNSWidgets.framework/Headers/TNSWidgets.h

@@ -22,3 +22,4 @@ FOUNDATION_EXPORT const unsigned char TNSWidgetsVersionString[];
 #import "TNSProcess.h"
 #import "NSString+Async.h"
 #import "NSData+Async.h"
+#import "NSFileHandle+Async.h"

packages/core/platforms/ios/TNSWidgets.xcframework/ios-arm64_x86_64-simulator/TNSWidgets.framework/_CodeSignature/CodeResources

@@ -8,6 +8,10 @@
 		<data>
 		9BsuK8QsA57YnHHgpWIgaHygSEk=
 		</data>
+		<key>Headers/NSFileHandle+Async.h</key>
+		<data>
+		iQtzsDHw/VTnFG27yW+QvGCeXGw=
+		</data>
 		<key>Headers/NSString+Async.h</key>
 		<data>
 		o8366y9zYMOVyObC3vtKKy/8jxA=
@@ -22,7 +26,7 @@
 		</data>
 		<key>Headers/TNSWidgets.h</key>
 		<data>
-		gUvu5bjZg5Aie5iJ1krxFmDrHwk=
+		ZFbCov7mFiXa4ZA/gAxqYHzRX7Q=
 		</data>
 		<key>Headers/UIImage+TNSBlocks.h</key>
 		<data>
@@ -34,7 +38,7 @@
 		</data>
 		<key>Info.plist</key>
 		<data>
-		RCfacSfbjEiH19hn34SSJzGdiFo=
+		myeIggkwNuTIqt7xlMgf8VGsKZ8=
 		</data>
 		<key>Modules/module.modulemap</key>
 		<data>
@@ -58,6 +62,13 @@
 			JdjuVUBed00Ged4cSDzYLXONUlESu+dae9KN0PYJ/nM=
 			</data>
 		</dict>
+		<key>Headers/NSFileHandle+Async.h</key>
+		<dict>
+			<key>hash2</key>
+			<data>
+			1IqS81dD1dbKccHZ0lYPMMF1zBPdp3InM+rdOFjBo+k=
+			</data>
+		</dict>
 		<key>Headers/NSString+Async.h</key>
 		<dict>
 			<key>hash2</key>
@@ -83,7 +94,7 @@
 		<dict>
 			<key>hash2</key>
 			<data>
-			V99t2zLwRPOs90tbGiQbhbdAFJlW7mp7X2R5337ewUA=
+			6L3xStgKRHkPvDZAHAUF+EMI3Skf5jvnoA4ED/WbB1w=
 			</data>
 		</dict>
 		<key>Headers/UIImage+TNSBlocks.h</key>

packages/types-android/src/lib/android/org.nativescript.widgets.d.ts

@@ -39,6 +39,9 @@
                     export function writeText(path: string, content: string, encoding: string, callback: CompleteCallback, context: any);
                     export function write(path: string, content: androidNative.Array<number>, callback: CompleteCallback, context: any);
                     export function writeBuffer(param0: string, param1: java.nio.ByteBuffer, param2: org.nativescript.widgets.Async.CompleteCallback, param3: any): void;
+                    export function append(path: string, content: androidNative.Array<number>, callback: CompleteCallback, context: any);
+                    export function appendBuffer(param0: string, param1: java.nio.ByteBuffer, param2: org.nativescript.widgets.Async.CompleteCallback, param3: any): void;
+                    export function appendText(path: string, content: string, encoding: string, callback: CompleteCallback, context: any);
                 }
 
                 export module Http {
@@ -646,7 +649,13 @@ declare module org {
 		export module widgets {
 			export class FileHelper {
 				public static class: java.lang.Class<org.nativescript.widgets.FileHelper>;
+                public appendTextSync(param0: globalAndroid.content.Context, param1: string, param2: string, param3: org.nativescript.widgets.FileHelper.Callback): void;
+                public appendText(param0: globalAndroid.content.Context, param1: string, param2: string, param3: org.nativescript.widgets.FileHelper.Callback): void;
 				public readText(param0: globalAndroid.content.Context, param1: string, param2: org.nativescript.widgets.FileHelper.Callback): void;
+                public appendSync(param0: globalAndroid.content.Context, param1: androidNative.Array<number>, param2: org.nativescript.widgets.FileHelper.Callback): void;
+                public append(param0: globalAndroid.content.Context, param1: androidNative.Array<number>, param2: org.nativescript.widgets.FileHelper.Callback): void;
+                public appendBufferSync(param0: globalAndroid.content.Context, param1: java.nio.ByteBuffer, param2: org.nativescript.widgets.FileHelper.Callback): void;
+                public appendBuffer(param0: globalAndroid.content.Context, param1: java.nio.ByteBuffer, param2: org.nativescript.widgets.FileHelper.Callback): void;
 				public writeBufferSync(param0: globalAndroid.content.Context, param1: java.nio.ByteBuffer, param2: org.nativescript.widgets.FileHelper.Callback): void;
 				public writeTextSync(param0: globalAndroid.content.Context, param1: string, param2: string, param3: org.nativescript.widgets.FileHelper.Callback): void;
 				public copyToFileSync(param0: globalAndroid.content.Context, param1: java.io.File, param2: org.nativescript.widgets.FileHelper.Callback): boolean;

packages/ui-mobile-base/android/widgets/src/main/AndroidManifest.xml

@@ -1,6 +1,9 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.nativescript.widgets">
 
+<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="28"/>
+<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="28"/>
+
     <application
         android:allowBackup="true">
 

packages/ui-mobile-base/android/widgets/src/main/java/org/nativescript/widgets/Async.java

@@ -1,11 +1,13 @@
 package org.nativescript.widgets;
 
+import android.content.ContentValues;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Looper;
 import android.util.Base64;
 import android.util.Log;
@@ -599,19 +601,87 @@ public class Async {
 
 	public static class File {
 
+		static void updateValue(Context context, Uri uri) {
+			ContentValues values = new ContentValues();
+			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+				context.getContentResolver().update(uri, values, null);
+			} else {
+				context.getContentResolver().update(uri, values, null, null);
+			}
+		}
+
+		public static void append(final String path, final byte[] content, final CompleteCallback callback, final Object context) {
+			final android.os.Handler mHandler = new android.os.Handler(Looper.myLooper());
+			threadPoolExecutor().execute(new Runnable() {
+				@Override
+				public void run() {
+					final AppendTask task = new AppendTask(callback, context);
+					final boolean result = task.doInBackground(path, content);
+					mHandler.post(new Runnable() {
+						@Override
+						public void run() {
+							task.onPostExecute(result);
+						}
+					});
+				}
+			});
+		}
+
+		public static void appendBuffer(final String path, final ByteBuffer content, final CompleteCallback callback, final Object context) {
+			final android.os.Handler mHandler = new android.os.Handler(Looper.myLooper());
+			threadPoolExecutor().execute(new Runnable() {
+				@Override
+				public void run() {
+					final AppendBufferTask task = new AppendBufferTask(callback, context);
+					final boolean result = task.doInBackground(path, content);
+					mHandler.post(new Runnable() {
+						@Override
+						public void run() {
+							task.onPostExecute(result);
+						}
+					});
+				}
+			});
+		}
+
+		public static void appendText(final String path, final String content, final String encoding, final CompleteCallback callback, final Object context) {
+			final android.os.Handler mHandler = new android.os.Handler(Looper.myLooper());
+			threadPoolExecutor().execute(new Runnable() {
+				@Override
+				public void run() {
+					final AppendTextTask task = new AppendTextTask(callback, context);
+					final boolean result = task.doInBackground(path, content, encoding);
+					mHandler.post(new Runnable() {
+						@Override
+						public void run() {
+							task.onPostExecute(result);
+						}
+					});
+				}
+			});
+		}
+
 		public static boolean copySync(final String src, final String dest, final Context context) throws Exception {
 			InputStream is;
 			OutputStream os;
-
+			boolean requiresUpdate = false;
 			if(src.startsWith("content://")){
 				is = context.getContentResolver().openInputStream(Uri.parse(src));
 			}else is = new FileInputStream(new java.io.File(src));
 
 			if(dest.startsWith("content://")){
 				os = context.getContentResolver().openOutputStream(Uri.parse(dest));
+				requiresUpdate = true;
 			}else os = new FileOutputStream(new java.io.File(dest));
 
-			return copySync(is, os, context);
+			boolean ret = copySync(is, os, context);
+
+			if(ret && requiresUpdate){
+				updateValue(context, Uri.parse(dest));
+			}
+
+			return ret;
+
 		}
 
 		public static boolean copySync(final InputStream src, final OutputStream dest, final Object context) throws Exception {
@@ -630,15 +700,33 @@ public class Async {
 				InputStream is;
 				OutputStream os;
 
+				boolean requiresUpdate = false;
+
 				if(src.startsWith("content://")){
 					is = context.getContentResolver().openInputStream(Uri.parse(src));
 				}else is = new FileInputStream(new java.io.File(src));
 
 				if(dest.startsWith("content://")){
+					requiresUpdate = true;
 					os = context.getContentResolver().openOutputStream(Uri.parse(dest));
 				}else os = new FileOutputStream(new java.io.File(dest));
 
-				copy(is, os, callback, context);
+				boolean finalRequiresUpdate = requiresUpdate;
+				copy(is, os, new CompleteCallback() {
+					@Override
+					public void onComplete(Object result, Object tag) {
+						if(finalRequiresUpdate){
+							updateValue(context, Uri.parse(dest));
+						}
+						callback.onComplete(result, tag);
+					}
+
+					@Override
+					public void onError(String error, Object tag) {
+						callback.onError(error, tag);
+					}
+				}, context);
+
 			}catch (Exception exception){
 				callback.onError(exception.getMessage(), context);
 			}
@@ -666,11 +754,12 @@ public class Async {
 			return written;
 		}
 
-
 		public static void copy(final InputStream src, final OutputStream dest, final CompleteCallback callback, final Object context) {
 			final android.os.Handler mHandler = new android.os.Handler(Looper.myLooper());
 			threadPoolExecutor().execute((Runnable) () -> {
 
+				boolean done = false;
+				Exception error = null;
 				try (InputStream is = src; OutputStream os = dest){
 					ReadableByteChannel isc = java.nio.channels.Channels.newChannel(is);
 					WritableByteChannel osc = java.nio.channels.Channels.newChannel(os);
@@ -679,10 +768,19 @@ public class Async {
 
 					int written = fastChannelCopy(isc, osc);
 
-					mHandler.post(() -> callback.onComplete(size == written, context));
+					done = size == written;
 
 				} catch (Exception e) {
-					mHandler.post(() -> callback.onError(e.getMessage(), context));
+					error = e;
+
+				}finally {
+					if (error != null){
+						Exception finalError = error;
+						mHandler.post(() -> callback.onError(finalError.getMessage(), context));
+					}else {
+						boolean finalDone = done;
+						mHandler.post(() -> callback.onComplete(finalDone, context));
+					}
 				}
 			});
 		}
@@ -1086,5 +1184,146 @@ public class Async {
 			}
 		}
 
+		static class AppendTask {
+			private final CompleteCallback callback;
+			private final Object context;
+
+			public AppendTask(CompleteCallback callback, Object context) {
+				this.callback = callback;
+				this.context = context;
+			}
+
+			protected boolean doInBackground(Object... params) {
+				java.io.File javaFile = new java.io.File((String) params[0]);
+				FileOutputStream stream = null;
+				byte[] content = (byte[]) params[1];
+
+				try {
+					stream = new FileOutputStream(javaFile, true);
+					stream.write(content, 0, content.length);
+
+					return true;
+				} catch (FileNotFoundException e) {
+					Log.e(TAG, "Failed to append file, FileNotFoundException: " + e.getMessage());
+					return false;
+				} catch (IOException e) {
+					Log.e(TAG, "Failed to write file, IOException: " + e.getMessage());
+					return false;
+				} finally {
+					if (stream != null) {
+						try {
+							stream.close();
+						} catch (IOException e) {
+							Log.e(TAG, "Failed to close stream, IOException: " + e.getMessage());
+						}
+					}
+				}
+			}
+
+			protected void onPostExecute(final boolean result) {
+				if (result) {
+					this.callback.onComplete(null, this.context);
+				} else {
+					this.callback.onError("AppendTask returns no result.", this.context);
+				}
+			}
+		}
+
+		static class AppendBufferTask {
+			private final CompleteCallback callback;
+			private final Object context;
+
+			public AppendBufferTask(CompleteCallback callback, Object context) {
+				this.callback = callback;
+				this.context = context;
+			}
+
+			protected boolean doInBackground(Object... params) {
+				java.io.File javaFile = new java.io.File((String) params[0]);
+				FileOutputStream stream = null;
+				ByteBuffer content = (ByteBuffer) params[1];
+
+				try {
+					stream = new FileOutputStream(javaFile, true);
+					FileChannel channel = stream.getChannel();
+					content.rewind();
+					channel.write(content);
+					content.rewind();
+					return true;
+				} catch (FileNotFoundException e) {
+					Log.e(TAG, "Failed to append to file, FileNotFoundException: " + e.getMessage());
+					return false;
+				} catch (IOException e) {
+					Log.e(TAG, "Failed to append file, IOException: " + e.getMessage());
+					return false;
+				} finally {
+					if (stream != null) {
+						try {
+							stream.close();
+						} catch (IOException e) {
+							Log.e(TAG, "Failed to close stream, IOException: " + e.getMessage());
+						}
+					}
+				}
+			}
+
+			protected void onPostExecute(final boolean result) {
+				if (result) {
+					this.callback.onComplete(null, this.context);
+				} else {
+					this.callback.onError("AppendTask returns no result.", this.context);
+				}
+			}
+		}
+
+		static class AppendTextTask {
+			private final CompleteCallback callback;
+			private final Object context;
+
+			public AppendTextTask(CompleteCallback callback, Object context) {
+				this.callback = callback;
+				this.context = context;
+			}
+
+			protected boolean doInBackground(String... params) {
+				java.io.File javaFile = new java.io.File(params[0]);
+				FileOutputStream stream = null;
+				try {
+					stream = new FileOutputStream(javaFile, true);
+
+					OutputStreamWriter writer = new OutputStreamWriter(stream, params[2]);
+					writer.write(params[1]);
+					writer.close();
+
+					return true;
+				} catch (FileNotFoundException e) {
+					Log.e(TAG, "Failed to append file, FileNotFoundException: " + e.getMessage());
+					return false;
+				} catch (UnsupportedEncodingException e) {
+					Log.e(TAG, "Failed to append file, UnsupportedEncodingException: " + e.getMessage());
+					return false;
+				} catch (IOException e) {
+					Log.e(TAG, "Failed to append file, IOException: " + e.getMessage());
+					return false;
+				} finally {
+					if (stream != null) {
+						try {
+							stream.close();
+						} catch (IOException e) {
+							Log.e(TAG, "Failed to close stream, IOException: " + e.getMessage());
+						}
+					}
+				}
+			}
+
+			protected void onPostExecute(final boolean result) {
+				if (result) {
+					this.callback.onComplete(null, this.context);
+				} else {
+					this.callback.onError("AppendTextTask returns no result.", this.context);
+				}
+			}
+		}
+
 	}
 }

packages/ui-mobile-base/android/widgets/src/main/java/org/nativescript/widgets/FileHelper.java

@@ -24,6 +24,7 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
+import java.lang.ref.WeakReference;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
 import java.nio.channels.FileChannel;
@@ -34,12 +35,13 @@ import java.util.concurrent.Executors;
 
 public class FileHelper {
     private Uri uri;
-	private long size;
     private String name;
     private String mime;
     private long lastModified;
-	private ExecutorService executor = Executors.newSingleThreadExecutor();
+    private final ExecutorService executor = Executors.newSingleThreadExecutor();
-	private Handler handler;
+    private final Handler handler;
+
+    private WeakReference<Context> context;
 
     public interface Callback {
         void onError(Exception exception);
@@ -59,12 +61,15 @@ public class FileHelper {
 
     private static @Nullable
     Cursor getCursor(Context context, Uri uri) {
-		Cursor cursor = null;
+        return getCursor(context, uri, new String[]{
-		String[] projections = {
-			MediaStore.MediaColumns.SIZE,
                 MediaStore.MediaColumns.DISPLAY_NAME,
                 MediaStore.MediaColumns.DATE_MODIFIED
-		};
+        });
+    }
+
+    private static @Nullable
+    Cursor getCursor(Context context, Uri uri, String[] projections) {
+        Cursor cursor = null;
         try {
             if (Build.VERSION.SDK_INT >= 19) {
                 if (DocumentsContract.isDocumentUri(context, uri)) {
@@ -115,7 +120,11 @@ public class FileHelper {
     public static @Nullable
     FileHelper fromString(Context context, String string) {
         try {
-			return fromUri(context, Uri.parse(string));
+            FileHelper ret = fromUri(context, Uri.parse(string));
+            if (ret != null) {
+                ret.context = new WeakReference<>(context);
+            }
+            return ret;
         } catch (Exception e) {
             return null;
         }
@@ -166,10 +175,10 @@ public class FileHelper {
                 return null;
             }
             FileHelper helper = new FileHelper(uri);
-			helper.size = file.length();
             helper.name = file.getName();
             helper.mime = context.getContentResolver().getType(uri);
             helper.lastModified = file.lastModified() / 1000;
+            helper.context = new WeakReference<>(context);
             return helper;
         }
 
@@ -182,10 +191,6 @@ public class FileHelper {
         boolean moved = cursor.moveToFirst();
         FileHelper helper = null;
         if (moved) {
-			int sizeIndex = cursor.getColumnIndex(
-					MediaStore.MediaColumns.SIZE
-			);
-
             int nameIndex = cursor.getColumnIndex(
                     MediaStore.MediaColumns.DISPLAY_NAME
             );
@@ -195,15 +200,51 @@ public class FileHelper {
             );
 
             helper = new FileHelper(uri);
-			helper.size = cursor.getLong(sizeIndex);
             helper.name = cursor.getString(nameIndex);
             helper.mime = context.getContentResolver().getType(uri);
             helper.lastModified = cursor.getLong(lastModifiedIndex);
+            helper.context = new WeakReference<>(context);
         }
         cursor.close();
+
         return helper;
     }
 
+    private long getFileSize() {
+        Context context = this.context.get();
+        if (context == null) {
+            return 0;
+        }
+        if (Build.VERSION.SDK_INT >= 19 && isExternalStorageDocument(uri)) {
+            File file = getFile(context, uri);
+            if (file == null) {
+                return 0;
+            }
+            return file.length();
+        }
+
+        Cursor cursor = getCursor(context, uri, null);
+
+        if (cursor == null) {
+            return 0;
+        }
+
+        long size = 0;
+
+        boolean moved = cursor.moveToFirst();
+        if (moved) {
+            int sizeIndex = cursor.getColumnIndex(
+                    MediaStore.MediaColumns.SIZE
+            );
+
+            size = cursor.getLong(sizeIndex);
+
+        }
+        cursor.close();
+
+        return size;
+    }
+
     private void updateInternal(Context context) {
         updateInternal(context, true);
     }
@@ -247,10 +288,6 @@ public class FileHelper {
         boolean moved = cursor.moveToFirst();
 
         if (moved) {
-			int sizeIndex = cursor.getColumnIndex(
-					MediaStore.MediaColumns.SIZE
-			);
-
             int nameIndex = cursor.getColumnIndex(
                     MediaStore.MediaColumns.DISPLAY_NAME
             );
@@ -259,7 +296,6 @@ public class FileHelper {
                     MediaStore.MediaColumns.DATE_MODIFIED
             );
 
-			size = cursor.getLong(sizeIndex);
             name = cursor.getString(nameIndex);
             mime = context.getContentResolver().getType(uri);
             lastModified = cursor.getLong(lastModifiedIndex);
@@ -269,7 +305,7 @@ public class FileHelper {
     }
 
     public long getSize() {
-		return size;
+        return getFileSize();
     }
 
     public String getName() {
@@ -308,16 +344,83 @@ public class FileHelper {
     }
 
     private OutputStream getOutputStream(Context context, Uri uri) throws Exception {
+        return getOutputStream(context, uri, false);
+    }
+
+    private OutputStream getOutputStream(Context context, Uri uri, boolean append) throws Exception {
         if (Build.VERSION.SDK_INT >= 19) {
             if (isExternalStorageDocument(uri)) {
                 File file = getFile(context, uri);
-				return new FileOutputStream(file);
+                return new FileOutputStream(file, append);
             }
             if (DocumentsContract.isDocumentUri(context, uri)) {
-				return context.getContentResolver().openOutputStream(DocumentFile.fromSingleUri(context, uri).getUri());
+                return context.getContentResolver().openOutputStream(DocumentFile.fromSingleUri(context, uri).getUri(), append ? "wa" : "w");
             }
         }
-		return context.getContentResolver().openOutputStream(uri);
+        return context.getContentResolver().openOutputStream(uri, append ? "wa" : "w");
+    }
+
+    public void appendSync(Context context, byte[] content, @Nullable Callback callback) {
+        try {
+            writeSyncInternal(context, content, true);
+        } catch (Exception e) {
+            if (callback != null) {
+                callback.onError(e);
+            }
+        }
+    }
+
+    public void append(Context context, byte[] content, Callback callback) {
+        executor.execute(() -> {
+            try {
+                writeSyncInternal(context, content, true);
+                handler.post(() -> callback.onSuccess(null));
+            } catch (Exception e) {
+                handler.post(() -> callback.onError(e));
+            }
+        });
+    }
+
+    public void appendBufferSync(Context context, ByteBuffer content, @Nullable Callback callback) {
+        try {
+            writeBufferSyncInternal(context, content, true);
+        } catch (Exception e) {
+            if (callback != null) {
+                callback.onError(e);
+            }
+        }
+    }
+
+    public void appendBuffer(Context context, ByteBuffer content, Callback callback) {
+        executor.execute(() -> {
+            try {
+                writeBufferSyncInternal(context, content, true);
+                handler.post(() -> callback.onSuccess(null));
+            } catch (Exception e) {
+                handler.post(() -> callback.onError(e));
+            }
+        });
+    }
+
+    public void appendTextSync(Context context, String content, @Nullable String encoding, @Nullable Callback callback) {
+        try {
+            writeTextSyncInternal(context, content, encoding, true);
+        } catch (Exception e) {
+            if (callback != null) {
+                callback.onError(e);
+            }
+        }
+    }
+
+    public void appendText(Context context, String content, @Nullable String encoding, Callback callback) {
+        executor.execute(() -> {
+            try {
+                writeTextSyncInternal(context, content, encoding, true);
+                handler.post(() -> callback.onSuccess(null));
+            } catch (Exception e) {
+                handler.post(() -> callback.onError(e));
+            }
+        });
     }
 
     private byte[] readSyncInternal(Context context) throws Exception {
@@ -429,15 +532,23 @@ public class FileHelper {
     }
 
     private void writeSyncInternal(Context context, byte[] content) throws Exception {
-		OutputStream os = getOutputStream(context, uri);
+        writeSyncInternal(context, content, false);
+    }
+
+    private void writeSyncInternal(Context context, byte[] content, boolean append) throws Exception {
+        OutputStream os = getOutputStream(context, uri, append);
         os.write(content, 0, content.length);
         os.flush();
         os.close();
         updateInternal(context);
     }
 
-	private void writeBufferSyncInternal(Context context,ByteBuffer content) throws Exception {
+    private void writeBufferSyncInternal(Context context, ByteBuffer content) throws Exception {
-		OutputStream os = getOutputStream(context, uri);
+        writeBufferSyncInternal(context, content, false);
+    }
+
+    private void writeBufferSyncInternal(Context context, ByteBuffer content, boolean append) throws Exception {
+        OutputStream os = getOutputStream(context, uri, append);
         WritableByteChannel channel = Channels.newChannel(os);
         channel.write(content);
         os.flush();
@@ -488,7 +599,11 @@ public class FileHelper {
     }
 
     private void writeTextSyncInternal(Context context, String content, @Nullable String encoding) throws Exception {
-		OutputStream os = getOutputStream(context, uri);
+        writeTextSyncInternal(context, content, encoding, false);
+    }
+
+    private void writeTextSyncInternal(Context context, String content, @Nullable String encoding, boolean append) throws Exception {
+        OutputStream os = getOutputStream(context, uri, append);
         String characterSet = encoding;
         if (characterSet == null) {
             characterSet = "UTF-8";

packages/ui-mobile-base/ios/TNSWidgets/TNSWidgets.xcodeproj/project.pbxproj

@@ -19,6 +19,8 @@
 		D004031022F781A50089EAD8 /* NSString+Async.m in Sources */ = {isa = PBXBuildFile; fileRef = D004030E22F781A50089EAD8 /* NSString+Async.m */; };
 		D004031322FA27D60089EAD8 /* NSData+Async.h in Headers */ = {isa = PBXBuildFile; fileRef = D004031122FA27D60089EAD8 /* NSData+Async.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		D004031422FA27D60089EAD8 /* NSData+Async.m in Sources */ = {isa = PBXBuildFile; fileRef = D004031222FA27D60089EAD8 /* NSData+Async.m */; };
+		F11DE2162A02F39A00B70DC5 /* NSFileHandle+Async.m in Sources */ = {isa = PBXBuildFile; fileRef = F11DE2152A02F39A00B70DC5 /* NSFileHandle+Async.m */; };
+		F11DE2182A02F3B500B70DC5 /* NSFileHandle+Async.h in Headers */ = {isa = PBXBuildFile; fileRef = F11DE2172A02F3B500B70DC5 /* NSFileHandle+Async.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		F915D3551EC9EF5E00071914 /* TNSProcess.m in Sources */ = {isa = PBXBuildFile; fileRef = F915D3531EC9EF5E00071914 /* TNSProcess.m */; };
 		F915D3561EC9EF5E00071914 /* TNSProcess.h in Headers */ = {isa = PBXBuildFile; fileRef = F915D3541EC9EF5E00071914 /* TNSProcess.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		F98F5CB31CD0EFEA00978308 /* TNSWidgets.h in Headers */ = {isa = PBXBuildFile; fileRef = F98F5CB21CD0EFEA00978308 /* TNSWidgets.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -51,6 +53,8 @@
 		D004030E22F781A50089EAD8 /* NSString+Async.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSString+Async.m"; sourceTree = "<group>"; };
 		D004031122FA27D60089EAD8 /* NSData+Async.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSData+Async.h"; sourceTree = "<group>"; };
 		D004031222FA27D60089EAD8 /* NSData+Async.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSData+Async.m"; sourceTree = "<group>"; };
+		F11DE2152A02F39A00B70DC5 /* NSFileHandle+Async.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSFileHandle+Async.m"; sourceTree = "<group>"; };
+		F11DE2172A02F3B500B70DC5 /* NSFileHandle+Async.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSFileHandle+Async.h"; sourceTree = "<group>"; };
 		F915D3531EC9EF5E00071914 /* TNSProcess.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = TNSProcess.m; path = ../TNSProcess.m; sourceTree = "<group>"; };
 		F915D3541EC9EF5E00071914 /* TNSProcess.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = TNSProcess.h; path = ../TNSProcess.h; sourceTree = "<group>"; };
 		F98F5CAF1CD0EFEA00978308 /* TNSWidgets.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = TNSWidgets.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -121,6 +125,8 @@
 				B8E76F5D212C3134009CFCE2 /* UIView+PassThroughParent.m */,
 				D004031122FA27D60089EAD8 /* NSData+Async.h */,
 				D004031222FA27D60089EAD8 /* NSData+Async.m */,
+				F11DE2172A02F3B500B70DC5 /* NSFileHandle+Async.h */,
+				F11DE2152A02F39A00B70DC5 /* NSFileHandle+Async.m */,
 			);
 			path = TNSWidgets;
 			sourceTree = "<group>";
@@ -147,6 +153,7 @@
 				D004031322FA27D60089EAD8 /* NSData+Async.h in Headers */,
 				F98F5CCB1CD0F09E00978308 /* UIImage+TNSBlocks.h in Headers */,
 				B8E76F52212C2DA2009CFCE2 /* NSObject+Swizzling.h in Headers */,
+				F11DE2182A02F3B500B70DC5 /* NSFileHandle+Async.h in Headers */,
 				B8E76F5A212C2F4E009CFCE2 /* UIView+PropertyBag.h in Headers */,
 				D004030F22F781A50089EAD8 /* NSString+Async.h in Headers */,
 				8B7321CF1D097ECD00884AC6 /* TNSLabel.h in Headers */,
@@ -252,6 +259,7 @@
 			files = (
 				8B7321D01D097ECD00884AC6 /* TNSLabel.m in Sources */,
 				F915D3551EC9EF5E00071914 /* TNSProcess.m in Sources */,
+				F11DE2162A02F39A00B70DC5 /* NSFileHandle+Async.m in Sources */,
 				F98F5CCC1CD0F09E00978308 /* UIImage+TNSBlocks.m in Sources */,
 				B8E76F53212C2DA2009CFCE2 /* NSObject+Swizzling.m in Sources */,
 				D004031022F781A50089EAD8 /* NSString+Async.m in Sources */,

packages/ui-mobile-base/ios/TNSWidgets/TNSWidgets/NSFileHandle+Async.h

@@ -0,0 +1,22 @@
+//
+//  NSFileHandle+Async.h
+//  TNSWidgets
+//
+//  Created by Osei Fortune on 03/05/2023.
+//  Copyright © 2023 Telerik A D. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSFileHandle (Async)
+
+- (void)appendData:(nonnull NSData*) data
+         completion:(void (^) (NSError*))callback;
+
++ (void)fileHandleWith:(NSString *)path data:(NSData *)data completion:(void (^)(NSFileHandle*,NSError*))callback;
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/ui-mobile-base/ios/TNSWidgets/TNSWidgets/NSFileHandle+Async.m

@@ -0,0 +1,82 @@
+//
+//  NSFileHandle+Async.m
+//  TNSWidgets
+//
+//  Created by Osei Fortune on 03/05/2023.
+//  Copyright © 2023 Telerik A D. All rights reserved.
+//
+
+#import "NSFileHandle+Async.h"
+
+@implementation NSFileHandle(Async)
+
+- (void)appendData:(NSData *)data completion:(void (^)(NSError*))callback {
+    dispatch_queue_t asyncQueue = dispatch_queue_create("org.nativescript.TNSWidgets.fileHandle", NULL);
+    dispatch_async(asyncQueue, ^(void) {
+        NSError *error = nil;
+        
+        if (@available(iOS 13.0, *)) {
+            [self seekToEndReturningOffset:nil error:&error];
+            [self writeData:data error:&error];
+        } else {
+            @try {
+                [self seekToEndOfFile];
+                [self writeData:data];
+            } @catch (NSException *exception) {
+              
+                NSMutableDictionary * info = [NSMutableDictionary dictionary];
+                   [info setValue:exception.name forKey:@"ExceptionName"];
+                   [info setValue:exception.reason forKey:@"ExceptionReason"];
+                   [info setValue:exception.callStackReturnAddresses forKey:@"ExceptionCallStackReturnAddresses"];
+                   [info setValue:exception.callStackSymbols forKey:@"ExceptionCallStackSymbols"];
+                   [info setValue:exception.userInfo forKey:@"ExceptionUserInfo"];
+
+                error = [[NSError alloc] initWithDomain:@"" code: 1 userInfo:info];
+                
+            }
+        }
+       
+        
+        dispatch_async(dispatch_get_main_queue(), ^(void) {
+            callback(error);
+        });
+        
+    });
+}
+
++ (void)fileHandleWith:(NSString *)path data:(NSData *)data completion:(void (^)(NSFileHandle*, NSError*))callback {
+    dispatch_queue_t asyncQueue = dispatch_queue_create("org.nativescript.TNSWidgets.fileHandle", NULL);
+    dispatch_async(asyncQueue, ^(void) {
+        NSFileHandle* handle = [NSFileHandle fileHandleForWritingAtPath: path];
+        NSError *error = nil;
+        
+        if (@available(iOS 13.0, *)) {
+            [handle seekToEndReturningOffset:nil error:&error];
+            [handle writeData:data error:&error];
+        } else {
+            @try {
+                [handle seekToEndOfFile];
+                [handle writeData:data];
+            } @catch (NSException *exception) {
+              
+                NSMutableDictionary * info = [NSMutableDictionary dictionary];
+                   [info setValue:exception.name forKey:@"ExceptionName"];
+                   [info setValue:exception.reason forKey:@"ExceptionReason"];
+                   [info setValue:exception.callStackReturnAddresses forKey:@"ExceptionCallStackReturnAddresses"];
+                   [info setValue:exception.callStackSymbols forKey:@"ExceptionCallStackSymbols"];
+                   [info setValue:exception.userInfo forKey:@"ExceptionUserInfo"];
+
+                error = [[NSError alloc] initWithDomain:@"" code: 1 userInfo:info];
+                
+            }
+        }
+       
+        
+        dispatch_async(dispatch_get_main_queue(), ^(void) {
+            callback(handle,error);
+        });
+        
+    });
+}
+
+@end

packages/ui-mobile-base/ios/TNSWidgets/TNSWidgets/TNSWidgets.h

@@ -22,3 +22,4 @@ FOUNDATION_EXPORT const unsigned char TNSWidgetsVersionString[];
 #import "TNSProcess.h"
 #import "NSString+Async.h"
 #import "NSData+Async.h"
+#import "NSFileHandle+Async.h"