file-promisify

Utilities for file and image handling, in Browsers, with Promise.

Live demo

Installation

Node.js

$ npm install --save file-promisify

Browser via CDN

<script src="https://cdn.jsdelivr.net/npm/file-promisify/dist/index.umd.js"></script>

Usage

import Files from 'file-promisify'

const instance = new Files()

/** open file dialog */
instance.select()
  .then(([blob]) => {})
  .catch(error => {})

/** open file dialog for selecting multiple files */
instance.select({ multiple: true })
  .then(blobs => {})
  .catch(error => {})

/** open file dialog for selecting an image file */
instance.select({ accept: 'image/*' })
  .then(blob => {
    /** wrap image into maximum 128 × 128 pixels */
    Files.processImage({ blob, width: 128, height: 128, crop: false })
      .then(dataUrl => {})
      .catch(error => {})

    /** crop image into 128 × 128 pixels exactly */
    Files.processImage({ blob, width: 128, height: 128, crop: true })
      .then(dataUrl => {})
      .catch(error => {})
  })
  .catch(error => {})

/** open directory dialog for selecting a directory (only webkit) */
instance.selectDirectory()
  .then(blobs => {})
  .catch(error => {})

API

instance.select({ multiple: [multiple], accept: [accept] })

Open a file dialog.

Parameter	Type	Description	Default
multiple	Boolean	Multiple selection or not.	false
accept	String	MIME type accepted.	'*/*'

• Returns: Promise<FileList>

instance.selectDirectory()

Open a directory dialog. (only webkit)

• Returns: Promise<FileList>

Files.processImage({ blob: <blob>, width: [width], height: [height], crop: [crop] })

Process image.

Parameter	Type	Description	Default
blob	Blob	The blob of image data.	(required)
width	Number	Target width.	null
height	Number	Target height.	null
crop	Boolean	Should crop or not. true for cropping image into dimension exactly, while false for wrapping image into the maximum dimension.	false

• Returns: Promise<String>

Files.urlToImage(<url>)

Fetch image URL into Image instance.

Parameter	Type	Description	Default
url	String	The URL of image.	(required)

• Returns: Promise<Image>

Files.blobToDataUrl(<blob>)

Transform Blob to data URL.

Parameter	Type	Description	Default
blob	Blob	The blob.	(required)

• Returns: Promise<String>

Files.dataUrlToBlob(<dataUrl>)

Transform data URL to Blob.

Parameter	Type	Description	Default
dataUrl	String	The data url.	(required)

• Returns: Promise<Blob>

Files.dataUrlToBase64(<dataUrl>)

Transform data URL to Base64 encoded string.

Parameter	Type	Description	Default
dataUrl	String	The data url.	(required)

• Returns: Promise<String>

Files.blobToBase64(<blob>)

Transform Blob to Base64 encoded string.

Parameter	Type	Description	Default
blob	Blob	The blob.	(required)

• Returns: Promise<String>

Files.blobToArrayBuffer(<blob>)

Transform Blob to ArrayBuffer.

Parameter	Type	Description	Default
blob	Blob	The blob.	(required)

• Returns: Promise<ArrayBuffer>

Files.blobToString(<blob>, [encoding])

Transform Blob to string.

Parameter	Type	Description	Default
blob	Blob	The blob.	(required)
encoding	String	The encoding.	'UTF-8'

• Returns: Promise<String>

Files.stringToBlob(<string>, [type])

Transform string to Blob.

Parameter	Type	Description	Default
string	String	The string.	(required)
type	String	The MIME type.	'application/octet-stream'

• Returns: Promise<Blob>

Files.stringToByteArray(<string>)

Transform string to byte array.

Parameter	Type	Description	Default
string	String	The string.	(required)

• Returns: Promise<Uint8Array>

Files.getImageOrientation(<blob>)

Get image orientation value from Blob.

Parameter	Type	Description	Default
blob	Blob	The blob of image data.	(required)

• Returns: Promise<Number>

Files.getMimeTypeFromDataUrl(<dataUrl>)

Get MIME type from data URL.

Parameter	Type	Description	Default
dataUrl	String	The data url.	(required)

• Returns: Promise<String>

License

MIT