extract-files

Reversibly extracts File, Blob and ReactNativeFile instances, with object paths, from an object tree and replaces them with null. FileList instances are treated as File instance arrays.

Usage

Install with npm:

npm install extract-files

See the extractFiles documentation to get started.

Reassembly

Loop and reinsert the extracted files using object-path:

import { extractFiles } from 'extract-files'
import objectPath from 'object-path'
import tree from './tree'

const files = extractFiles(tree)
const treePath = objectPath(tree)

files.forEach(({ path, file }) => treePath.set(path, file))

FileList instances in the original tree become File instance arrays when reassembled.

Support

• Node.js v6+
• Browsers > 0.5%, not dead
• React Native

API

Table of contents

• class ReactNativeFile
  • Examples
• function extractFiles
  • Examples
• type ExtractedFile
• type ObjectPath
  • See
  • Examples
• type ReactNativeFileSubstitute
  • See
  • Examples

class ReactNativeFile

Used to mark a React Native File substitute in an object tree for extractFiles. It’s too risky to assume all objects with uri, type and name properties are files to extract.

Parameter	Type	Description
file	ReactNativeFileSubstitute	A React Native File substitute.

Examples

An extractable file in React Native.

import { ReactNativeFile } from 'extract-files'

const file = new ReactNativeFile({
  uri: uriFromCameraRoll,
  name: 'a.jpg',
  type: 'image/jpeg'
})

function extractFiles

Reversibly extracts File, Blob and ReactNativeFile instances, with object paths, from an object tree and replaces them with null. FileList instances are treated as File instance arrays.

Parameter	Type	Description
tree	Object	An object tree to extract files from. The tree itself must not be a file.
treePath	string? = ''	Optional object tree path to prefix file object tree paths.

Returns: Array<ExtractedFile> — Extracted files or an empty array if the tree is not an enumerable object.

Examples

Extracting files.

The following:

import { extractFiles } from 'extract-files'

console.log(
  extractFiles(
    {
      a: new File(['a'], 'a.txt', { type: 'text/plain' }),
      b: [
        {
          c: new File(['b'], 'b.txt', { type: 'text/plain' })
        }
      ]
    },
    'prefix'
  )
)

Logs:

[{
  path: 'prefix.a',
  file: [object File]
}, {
  path: 'prefix.b.0.c',
  file: [object File]
}]

type ExtractedFile

An extracted file.

Type: Object

Property	Type	Description
path	ObjectPath	Object path to the file in the original object tree.
file	File | Blob | ReactNativeFile	The extracted file.

type ObjectPath

String notation for the path to a node in an object tree.

Type: String

See

• object-path on npm.

Examples

Object path is property a, array index 0, object property b.

a.0.b

type ReactNativeFileSubstitute

A React Native File substitute for when using FormData.

Type: Object

Property	Type	Description
uri	String	Filesystem path.
name	String?	File name.
type	String?	File content type.

See

• React Native FormData polyfill source.

Examples

A camera roll file.

{
  uri: uriFromCameraRoll,
  name: 'a.jpg',
  type: 'image/jpeg'
}