require('fs')

UXP Provides Node.js style file system API, FSAPI. Unlike Entry based File or Folder classes, these methods can directly access a local file or folder with path or file descriptor. The starting point of a path in the native filesystem depends on the scheme. UXP supports plugin-specific storage schemes, such as "plugin:", "plugin-data:", and "plugin-temp:", as well as a native "file:" scheme for the path parameter.<br></br> Note:<br></br>

1. If there are no schemes defined for the path parameter of FSAPI methods, it considers to have "file:" scheme for the path.<br></br>
2. UWP(Universal Windows Platform) has the strict File access permissions, and UXP FSAPI may have access issues with anonymous filepaths. So, XD does not support this feature for compatibility across platforms.<br></br>
3. The native layer of UXP FSAPI is based on libUV except UWP powered features, such as FilePicker and Drag&Drop on Win10 XD.<br></br>

readFile(path, options, callback)

Reads data from the path asynchronously. The file format can be specified with the encoding options. If an encoding is not supplied, the file is assumed to be a binary format.

Returns: Promise<string|ArrayBuffer> - the contents of the file

Example

const data = await fs.readFile("plugin-data:/binaryFile.obj");

Example

const text = await fs.readFile("plugin-data:/textFile.txt", {encoding: "utf-8"});

readFileSync(path, options)

Reads data from the path synchronously. The file format can be specified with the encoding options. If an encoding is not supplied, the file is assumed to be a binary format.

Returns: string | ArrayBuffer - the contents of the file

Example

const data = fs.readFileSync("plugin-data:/binaryFile.obj");

Example

const text = fs.readFileSync("plugin-data:/textFile.txt", {encoding: "utf-8"});

writeFile(path, data, options, callback)

Writes data to the path asynchronously, appending if desired. The format of the file is controlled via the encoding option, and defaults to a binary format.

Returns: Promise<number> - the length of contents written to the file

Example

const bufLen = await fs.writeFile("plugin-data:/binaryFile.obj", new Uint8Array([1, 2, 3]));

Example

const strLen = await fs.writeFile("plugin-data:/textFile.txt", "It was a dark and stormy night.\n", {encoding: "utf-8"});

writeFileSync(path, data, options)

Writes data to a path synchronously, appending if desired. The format of the file is controlled via the encoding option, and defaults to a binary format.

Returns: number - the length of contents written to the file

Example

const bufLen = fs.writeFileSync("plugin-data:/binaryFile.obj", new Uint8Array([1, 2, 3]));

Example

const strLen = fs.writeFileSync("plugin-data:/textFile.txt", "It was a dark and stormy night.\n", {encoding: "utf-8"});

open(path, [flag], [mode], callback)

Opens or a creates a file asynchronously

Returns: Promise<number> - fd(file descriptor)

Example

const fd = await fs.open("plugin-data:/fileToRead.txt", "r");

close(fd, callback)

Closes a file descriptor asynchronously

Returns: number - 0 if succeeded, otherwise throws an Error

Example

await fs.close(fd);

read(fd, buffer, offset, length, position, callback)

Reads data in chunks from the file it refers to the file descriptor

Returns: Promise<Object> - { bytesRead: number, buffer: ArrayBuffer }
Throws:

• Error if invalid file descriptor is passed. if invalid parameter format or value is passed.

Example

const fileSize = 1024;
const buffer = new ArrayBuffer(fileSize);
const fd = await fs.open("plugin-data:/fileToRead.txt", "r");
let bytesReadInTotal = 0;
while (bytesReadInTotal < fileSize) {
    const { bytesRead } = await fs.read(fd, buffer, bytesReadInTotal, 128, -1);
    if (!bytesRead) {
        break;
    }
    bytesReadInTotal += bytesRead;
}
await fs.close(fd);

write(fd, buffer, offset, length, position, callback)

Writes data in chunks to the file it refers to the file descriptor

Returns: Promise<Object> - { bytesWritten, buffer }
Throws:

• Error if invalid file descriptor is passed if invalid parameter format or value is passed

Example

const fd = await fs.open("plugin-data:/fileToWrite.txt", "w+");
const data = "It was a dark and stormy night.\n";
const srcBuffer = new Uint8Array(data.length);
for (let i = 0; i < data.length; i++) {
 srcBuffer[i] = data.charCodeAt(i);
}
const { bytesWritten } = await fs.write(fd, srcBuffer.buffer, 0, srcBuffer.length, 0);
await fs.close(fd);

lstat(path, callback)

Gets information asynchronously from a file or a folder of the path

Returns: Promise<Object> - see Stats class in Node.js Note: Some methods or properties may not be supportive for the return object due to the platform limitation

Example

const stats = await fs.lstat("plugin-data:/textFile.txt");
const isFile = stats.isFile();

lstatSync(path)

Gets information synchronously from a file or a folder of the path

Returns: Object - see Stats class in Node.js Note: Some methods or properties may not be supportive for the return object due to the platform limitation

Example

const stats = fs.lstatSync("plugin-data:/textFile.txt");
const birthTime = stats.birthtime;

rename(oldPath, newPath, callback)

Renames or moves, if required, the file from the oldPath to the newPath

Returns: Promise<number> - 0 if succeeded, otherwise throws an Error

Example

fs.rename("plugin-data:/oldName.txt", "plugin-temp:/newName.txt");

copyFile(srcPath, destPath, flags, callback)

Copies a file or a folder from the source path to the destination path

Returns: Promise<number> - 0 if succeeded, otherwise throws an Error

Example

const data = fs.copyFile("plugin-data:/copyFrom.txt", "plugin-temp:/copyTo.txt");

unlink(path, callback)

Deletes a name with the file it refers to asynchronously

Returns: Promise<number> - 0 if succeeded, otherwise throws an Error

Example

await fs.unlink("plugin-data:/fileToDelete.txt");

mkdir(path, options, callback)

Creates a directory of the path asynchronously

Returns: Promise<number> - 0 if succeeded, otherwise throws an Error

Example

await fs.mkdir("plugin-data:/newDir");

rmdir(path, callback)

Removes a directory asynchronously

Returns: Promise<number> - 0 if succeeded, otherwise throws an Error

Example

await fs.rmdir("plugin-data:/dirToRemove");

readdir(path, callback)

Reads a directory to list the containing files and directories asynchronously

Returns: Promise<Array<string>> - string array of containing files and directories in the path

Example

const paths = await fs.readdir("plugin-data:/dirToRead");

readdirSync(path)

Reads a directory to list the containing files and directories synchronously

Returns: Array<string> - string array of containing files and directories in the path

Example

const paths = fs.readdirSync("plugin-data:/dirToRead");