Wraps FileReader in a Promise

Wraps FileReader in a Promise

npm install --save promise-file-reader Usage Basic syntax

const PromiseFileReader = require('promise-file-reader'); PromiseFileReader.readAsDataURL(fileData) .then(newImage) .catch(err => console.error(err)); Example: file input

import {readAsDataURL, readAsText, readAsArrayBuffer} from 'promise-file-reader'; function newImage(imageDataUrl) { ... } function newTextFile(text) { ... } function loadedArrayBuffer(arrayBuffer) { ... } // e.g. <input id="file-input" type="file" /> const fileInput = document.getElementById('file-input'); fileInput.addEventListener("change", handleFiles, false); function handleFiles(event) { const fileMetaData = event.target.files[0]; if(fileMetaData) { if (/^image/.test(fileMetaData.type)) { readAsDataURL(fileMetaData) .then(newImage) .catch(err => console.error(err)); } else { readAsText(fileMetaData) .then(newTextFile) .catch(err => console.error(err)); } // or readAsArrayBuffer(fileMetaData) .then(loadedArrayBuffer) .catch(err => console.error(err)); } }