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