File

File and data manipulation tools. Handle files, read data and work with binary content.

Eg File, Blob

interface Blob

A file-like object of immutable, raw data. Blobs represent data that isn't necessarily in a JavaScript-native format. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system.

Properties

size: number

readonly

type: string

readonly

Methods

arrayBuffer(): Promise<ArrayBuffer>

bytes(): Promise<Uint8Array<ArrayBuffer>>

slice(

start?: number,

end?: number,

contentType?: string,
): Blob

stream(): ReadableStream<Uint8Array<ArrayBuffer>>

text(): Promise<string>

textStream(): ReadableStream<string>

Returns a ReadableStream<string> that streams the blob's data decoded as UTF-8 text.

variable Blob

Properties

prototype: Blob

readonly

interface BlobPropertyBag

Properties

type: string

optional

endings: EndingType

optional

interface File

extends Blob

Provides information about files and allows JavaScript in a web page to access their content.

Properties

lastModified: number

readonly

name: string

readonly

webkitRelativePath: string

readonly

variable File

Provides information about files and allows JavaScript in a web page to access their content.

Properties

prototype: File

readonly

interface FilePropertyBag

extends BlobPropertyBag

Properties

lastModified: number

optional

interface FileReader

extends EventTarget

Lets web applications asynchronously read the contents of files (or raw data buffers) stored on the user's computer, using File or Blob objects to specify the file or data to read.

Properties

error: DOMException | null

readonly

onabort: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

onerror: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

onload: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

onloadend: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

onloadstart: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

onprogress: ((

this: FileReader,

ev: ProgressEvent<FileReader>,
) => any) | null

readyState: 
FileReader.EMPTY
 | FileReader.LOADING
 | FileReader.DONE

readonly

result: 
string
 | ArrayBuffer
 | null

readonly

EMPTY: 0

readonly

LOADING: 1

readonly

DONE: 2

readonly

Methods

abort(): void

readAsArrayBuffer(blob: Blob): void

readAsBinaryString(blob: Blob): void

deprecated

readAsDataURL(blob: Blob): void

readAsText(

blob: Blob,

encoding?: string,
): void

addEventListener<K extends keyof FileReaderEventMap>(

type: K,

listener: (

this: FileReader,

ev: FileReaderEventMap[K],
) => any,

options?: boolean | AddEventListenerOptions,
): void

addEventListener(

type: string,

listener: EventListenerOrEventListenerObject,

options?: boolean | AddEventListenerOptions,
): void

removeEventListener<K extends keyof FileReaderEventMap>(

type: K,

listener: (

this: FileReader,

ev: FileReaderEventMap[K],
) => any,

options?: boolean | EventListenerOptions,
): void

removeEventListener(

type: string,

listener: EventListenerOrEventListenerObject,

options?: boolean | EventListenerOptions,
): void

variable FileReader

The constructor object for FileReader, used to create a reader that asynchronously reads the contents of a Blob or File into memory.

Properties

prototype: FileReader

readonly

EMPTY: 0

readonly

LOADING: 1

readonly

DONE: 2

readonly

interface FileReaderEventMap

Properties

abort: ProgressEvent<FileReader>

error: ProgressEvent<FileReader>

load: ProgressEvent<FileReader>

loadend: ProgressEvent<FileReader>

loadstart: ProgressEvent<FileReader>

progress: ProgressEvent<FileReader>

type alias BlobPart

Definition


BufferSource
 | Blob
 | string

type alias EndingType

Definition

"transparent" | "native"