https://github.com/jahredhope/promise-file-reader

Wraps FileReader in a Promise
https://github.com/jahredhope/promise-file-reader

Last synced: 16 days ago
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Wraps FileReader in a Promise

• Host: GitHub
• URL: https://github.com/jahredhope/promise-file-reader
• Owner: jahredhope
• License: isc
• Created: 2016-06-09T06:51:55.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2022-06-26T08:49:02.000Z (over 2 years ago)
• Last Synced: 2024-10-19T02:00:38.044Z (29 days ago)
• Language: JavaScript
• Size: 14.6 KB
• Stars: 31
• Watchers: 3
• Forks: 9
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# promise-file-reader

Wraps [FileReader](https://developer.mozilla.org/en-US/docs/Web/API/FileReader) in a Promise

![travis ci](https://travis-ci.org/jahredhope/promise-file-reader.svg?branch=master)

[![npm](https://img.shields.io/npm/v/promise-file-reader.svg)](https://www.npmjs.com/package/promise-file-reader)

## Install

```

npm install --save promise-file-reader

```

## Usage

### Basic syntax

```javascript

const PromiseFileReader = require('promise-file-reader');

PromiseFileReader.readAsDataURL(fileData)

  .then(newImage)

  .catch(err => console.error(err));

```

### Example: file input

```javascript

import {readAsDataURL, readAsText, readAsArrayBuffer} from 'promise-file-reader';

function newImage(imageDataUrl) {

  ...

}

function newTextFile(text) {

  ...

}

function loadedArrayBuffer(arrayBuffer) {

  ...

}

// e.g. 

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));

  }

}

```