file-reader-promise

Wraps FileReader in a Promise.

simpler API of HTML5 FileReader:
``javascript
FileReaderPromise.readAsText(file)
.then(function (textResult) {})
`
Enjoy it.


Install

`
npm install --save file-reader-promise
`

Usage

$3

`javascript
const FileReaderPromise = require('file-reader-promise');

FileReaderPromise.readAsText(file)
.then(text)
.catch(err => console.error(err));
`

API

`javascript
FileReaderPromise.readAsArrayBuffer()
FileReaderPromise.readAsBinaryString()
FileReaderPromise.readAsDataURL()
FileReaderPromise.readAsText()

// you can get a simple value(event.target.result) at Promsie chain in default config.
FileReaderPromise.readAsText(file).then(textValue)
// but, if you want a original value, you can set a new config for FileReaderPromise:
const config = { enableSimplify: false }
FileReaderPromise.set(config)
FileReaderPromise.readAsArrayBuffer(file)
.then(function (event) {
// event is original event of instanceOfFileReader.onload = function (event) {}
console.log(event.target.result)
console.log(event.timeStamp)
})
`

$3

`javascript
const FileReaderPromise = require('file-reader-promise');

function handleImage(imageDataUrl) {
// ...
}
function handleText(text) {
// ...
}
function handleArrayBuffer(arrayBuffer) {
// ...
}

// e.g.
const fileInput = document.getElementById('file-input');
fileInput.addEventListener("change", handleFiles, false);
function handleFiles(event) {
const file = event.target.files[0];

if(file) {
if (/^image/.test(file.type)) {
FileReaderPromise.readAsDataURL(file)
.then(handleImage)
.catch(err => console.error(err));
} else {
FileReaderPromise.readAsText(file)
.then(handleText)
.catch(err => console.error(err));
}
// or
FileReaderPromise.readAsArrayBuffer(file)
.then(handleArrayBuffer)
.catch(err => console.error(err));
}
}
``