File

Represents a file on a file system. Provides methods for reading from and writing to the file. You'll never instantiate a File directly; instead you'll get access via a storage.FileSystemProvider. Keep in mind that File as such doesn't need a require() statement, however a localFileSystem will need it.

Example

// Get the object of a File instance
const fs = require('uxp').storage.localFileSystem;
const file = await fs.createEntryWithUrl("file:/Users/user/Documents/tmp"); // Gets a File instance
console.log(file.isFile); // returns true
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1// Get the object of a File instance
2const fs = require('uxp').storage.localFileSystem;
3const file = await fs.createEntryWithUrl("file:/Users/user/Documents/tmp"); // Gets a File instance
4console.log(file.isFile); // returns true

isFile

Indicates that this instance is a file.

Example

if (anEntry.isFile) {
    await anEntry.read();
}
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1if (anEntry.isFile) {
2    await anEntry.read();
3}

mode : Symbol

Indicates whether this file is read-only or read-write. See readOnly and readWrite.

Example

if (aFile.mode === modes.readOnly) {
    throw new Error("Can't write to a file opened as read-only.");
}
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1if (aFile.mode === modes.readOnly) {
2    throw new Error("Can't write to a file opened as read-only.");
3}

read(options)

Reads data from the file and returns it. The file format can be specified with the format option. If a format is not supplied, the file is assumed to be a text file using UTF8 encoding.

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

Example

const text = await myNovel.read();
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const text = await myNovel.read();

Example

const data = await myNovel.read({format: formats.binary});
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const data = await myNovel.read({format: formats.binary});

write(data, options)

Writes data to a file, appending if desired. The format of the file is controlled via the format option, and defaults to UTF8.

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

• FileIsReadOnly if writing to a read-only file
• OutOfSpace If writing to the file causes the file system to exceed the available space (or quota)

Example

await myNovel.write("It was a dark and stormy night.\n");
await myNovel.write("Cliches and tropes aside, it really was.", {append: true});
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1await myNovel.write("It was a dark and stormy night.\n");
2await myNovel.write("Cliches and tropes aside, it really was.", {append: true});

Example

const data = new ArrayBuffer();
await aDataFile.write(data, {format: formats.binary});
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1const data = new ArrayBuffer();
2await aDataFile.write(data, {format: formats.binary});

isFile(entry)

Determines if the entry is a file or not. This is safe to use even if the entry is null or undefined.

Returns: boolean - if true, the entry is a file.