'use strict'
const {
staticPropertyDescriptors,
readOperation,
fireAProgressEvent
} = require('./util')
const {
kState,
kError,
kResult,
kEvents,
kAborted
} = require('./symbols')
const { webidl } = require('../fetch/webidl')
const { kEnumerableProperty } = require('../core/util')
class FileReader extends EventTarget {
constructor () {
super()
this[kState] = 'empty'
this[kResult] = null
this[kError] = null
this[kEvents] = {
loadend: null,
error: null,
abort: null,
load: null,
progress: null,
loadstart: null
}
}
/**
* @see https://w3c.github.io/FileAPI/#dfn-readAsArrayBuffer
* @param {import('buffer').Blob} blob
*/
readAsArrayBuffer (blob) {
webidl.brandCheck(this, FileReader)
webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsArrayBuffer' })
blob = webidl.converters.Blob(blob, { strict: false })
// The readAsArrayBuffer(blob) method, when invoked,
// must initiate a read operation for blob with ArrayBuffer.
readOperation(this, blob, 'ArrayBuffer')
}
/**
* @see https://w3c.github.io/FileAPI/#readAsBinaryString
* @param {import('buffer').Blob} blob
*/
readAsBinaryString (blob) {
webidl.brandCheck(this, FileReader)
webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsBinaryString' })
blob = webidl.converters.Blob(blob, { strict: false })
// The readAsBinaryString(blob) method, when invoked,
// must initiate a read operation for blob with BinaryString.
readOperation(this, blob, 'BinaryString')
}
/**
* @see https://w3c.github.io/FileAPI/#readAsDataText
* @param {import('buffer').Blob} blob
* @param {string?} encoding
*/
readAsText (blob, encoding = undefined) {
webidl.brandCheck(this, FileReader)
webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsText' })
blob = webidl.converters.Blob(blob, { strict: false })
if (encoding !== undefined) {
encoding = webidl.converters.DOMString(encoding)
}
// The readAsText(blob, encoding) method, when invoked,
// must initiate a read operation for blob with Text and encoding.
readOperation(this, blob, 'Text', encoding)
}
/**
* @see https://w3c.github.io/FileAPI/#dfn-readAsDataURL
* @param {import('buffer').Blob} blob
*/
readAsDataURL (blob) {
webidl.brandCheck(this, FileReader)
webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsDataURL' })
blob = webidl.converters.Blob(blob, { strict: false })
// The readAsDataURL(blob) method, when invoked, must
// initiate a read operation for blob with DataURL.
readOperation(this, blob, 'DataURL')
}
/**
* @see https://w3c.github.io/FileAPI/#dfn-abort
*/
abort () {
// 1. If this's state is "empty" or if this's state is
// "done" set this's result to null and terminate
// this algorithm.
if (this[kState] === 'empty' || this[kState] === 'done') {
this[kResult] = null
return
}
// 2. If this's state is "loading" set this's state to
// "done" and set this's result to null.
if (this[kState] === 'loading') {
this[kState] = 'done'
this[kResult] = null
}
// 3. If there are any tasks from this on the file reading
// task source in an affiliated task queue, then remove
// those tasks from that task queue.
this[kAborted] = true
// 4. Terminate the algorithm for the read method being processed.
// TODO
// 5. Fire a progress event called abort at this.
fireAProgressEvent('abort', this)
// 6. If this's state is not "loading", fire a progress
// event called loadend at this.
if (this[kState] !== 'loading') {
fireAProgressEvent('loadend', this)
}
}
/**
* @see https://w3c.github.io/FileAPI/#dom-filereader-readystate
*/
get readyState () {
webidl.brandCheck(this, FileReader)
switch (this[kState]) {
case 'empty': return this.EMPTY
case 'loading': return this.LOADING
case 'done': return this.DONE
}
}
/**
* @see https://w3c.github.io/FileAPI/#dom-filereader-result
*/
get result () {
webidl.brandCheck(this, FileReader)
// The result attribute’s getter, when invoked, must return
// this's result.
return this[kResult]
}
/**
* @see https://w3c.github.io/FileAPI/#dom-filereader-error
*/
get error () {
webidl.brandCheck(this, FileReader)
// The error attribute’s getter, when invoked, must return
// this's error.
return this[kError]
}
get onloadend () {
webidl.brandCheck(this, FileReader)
return this[kEvents].loadend
}
set onloadend (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].loadend) {
this.removeEventListener('loadend', this[kEvents].loadend)
}
if (typeof fn === 'function') {
this[kEvents].loadend = fn
this.addEventListener('loadend', fn)
} else {
this[kEvents].loadend = null
}
}
get onerror () {
webidl.brandCheck(this, FileReader)
return this[kEvents].error
}
set onerror (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].error) {
this.removeEventListener('error', this[kEvents].error)
}
if (typeof fn === 'function') {
this[kEvents].error = fn
this.addEventListener('error', fn)
} else {
this[kEvents].error = null
}
}
get onloadstart () {
webidl.brandCheck(this, FileReader)
return this[kEvents].loadstart
}
set onloadstart (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].loadstart) {
this.removeEventListener('loadstart', this[kEvents].loadstart)
}
if (typeof fn === 'function') {
this[kEvents].loadstart = fn
this.addEventListener('loadstart', fn)
} else {
this[kEvents].loadstart = null
}
}
get onprogress () {
webidl.brandCheck(this, FileReader)
return this[kEvents].progress
}
set onprogress (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].progress) {
this.removeEventListener('progress', this[kEvents].progress)
}
if (typeof fn === 'function') {
this[kEvents].progress = fn
this.addEventListener('progress', fn)
} else {
this[kEvents].progress = null
}
}
get onload () {
webidl.brandCheck(this, FileReader)
return this[kEvents].load
}
set onload (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].load) {
this.removeEventListener('load', this[kEvents].load)
}
if (typeof fn === 'function') {
this[kEvents].load = fn
this.addEventListener('load', fn)
} else {
this[kEvents].load = null
}
}
get onabort () {
webidl.brandCheck(this, FileReader)
return this[kEvents].abort
}
set onabort (fn) {
webidl.brandCheck(this, FileReader)
if (this[kEvents].abort) {
this.removeEventListener('abort', this[kEvents].abort)
}
if (typeof fn === 'function') {
this[kEvents].abort = fn
this.addEventListener('abort', fn)
} else {
this[kEvents].abort = null
}
}
}
// https://w3c.github.io/FileAPI/#dom-filereader-empty
FileReader.EMPTY = FileReader.prototype.EMPTY = 0
// https://w3c.github.io/FileAPI/#dom-filereader-loading
FileReader.LOADING = FileReader.prototype.LOADING = 1
// https://w3c.github.io/FileAPI/#dom-filereader-done
FileReader.DONE = FileReader.prototype.DONE = 2
Object.defineProperties(FileReader.prototype, {
EMPTY: staticPropertyDescriptors,
LOADING: staticPropertyDescriptors,
DONE: staticPropertyDescriptors,
readAsArrayBuffer: kEnumerableProperty,
readAsBinaryString: kEnumerableProperty,
readAsText: kEnumerableProperty,
readAsDataURL: kEnumerableProperty,
abort: kEnumerableProperty,
readyState: kEnumerableProperty,
result: kEnumerableProperty,
error: kEnumerableProperty,
onloadstart: kEnumerableProperty,
onprogress: kEnumerableProperty,
onload: kEnumerableProperty,
onabort: kEnumerableProperty,
onerror: kEnumerableProperty,
onloadend: kEnumerableProperty,
[Symbol.toStringTag]: {
value: 'FileReader',
writable: false,
enumerable: false,
configurable: true
}
})
Object.defineProperties(FileReader, {
EMPTY: staticPropertyDescriptors,
LOADING: staticPropertyDescriptors,
DONE: staticPropertyDescriptors
})
module.exports = {
FileReader
}
