index.js

// @flow
/**
 * Handles HTTP background file uploads from an iOS or Android device.
 */
import { NativeModules, DeviceEventEmitter, Platform } from 'react-native'

export type UploadEvent = 'progress' | 'error' | 'completed' | 'cancelled'

export type NotificationArgs = {
  enabled: boolean
}

export type StartUploadArgs = {
  url: string,
  path: string,
  method?: 'PUT' | 'POST',
  // Optional, because raw is default
  type?: 'raw' | 'multipart',
  // This option is needed for multipart type
  field?: string,
  customUploadId?: string,
  // parameters are supported only in multipart type
  parameters?: { [string]: string },
  headers?: Object,
  notification?: NotificationArgs
}

const NativeModule = NativeModules.VydiaRNFileUploader || NativeModules.RNFileUploader // iOS is VydiaRNFileUploader and Android is NativeModules 
const eventPrefix = 'RNFileUploader-'

// for IOS, register event listeners or else they don't fire on DeviceEventEmitter
if (NativeModules.VydiaRNFileUploader) {
  NativeModule.addListener(eventPrefix + 'progress')
  NativeModule.addListener(eventPrefix + 'error')
  NativeModule.addListener(eventPrefix + 'cancelled')
  NativeModule.addListener(eventPrefix + 'completed')
}

/*
Gets file information for the path specified.
Example valid path is:
  Android: '/storage/extSdCard/DCIM/Camera/20161116_074726.mp4'
  iOS: 'file:///var/mobile/Containers/Data/Application/3C8A0EFB-A316-45C0-A30A-761BF8CCF2F8/tmp/trim.A5F76017-14E9-4890-907E-36A045AF9436.MOV;

Returns an object:
  If the file exists: {extension: "mp4", size: "3804316", exists: true, mimeType: "video/mp4", name: "20161116_074726.mp4"}
  If the file doesn't exist: {exists: false} and might possibly include name or extension

The promise should never be rejected.
*/
export const getFileInfo = (path: string): Promise<Object> => {
  return NativeModule.getFileInfo(path)
  .then(data => {
    if (data.size) {  // size comes back as a string on android so we convert it here.  if it's already a number this won't hurt anything
      data.size = +data.size
    }
    return data
  })
}

/*
Starts uploading a file to an HTTP endpoint.  
Options object:
{
  url: string.  url to post to.
  path: string.  path to the file on the device
  headers: hash of name/value header pairs
  method: HTTP method to use.  Default is "POST"
  notification: hash for customizing tray notifiaction
    enabled: boolean to enable/disabled notifications, true by default.
}

Returns a promise with the string ID of the upload.  Will reject if there is a connection problem, the file doesn't exist, or there is some other problem.

It is recommended to add listeners in the .then of this promise.

*/
export const startUpload = (options: StartUploadArgs): Promise<string> => NativeModule.startUpload(options)


/*
Starts listening events from a foreground service

notification: hash for customizing tray notifiaction

Returns a promise with. Will reject if there is an exception.

It is recommended call this once, before any upload request.

*/
export const startEventListener = (options): Promise<void> => {
  if (Platform.OS === "android") {
    return NativeModule.startEventListener(options)
  } else {
    return Promise.resolve(false);
  }
}

/*
Stops listening events.

Returns a promise with. Will reject if there is an exception.

It is recommended to call this after all of the upload requests finishes or fails. 
If it's not called, foreground service is never stopped.

*/
export const stopEventListener = (): Promise<void> => {
  if (Platform.OS === "android") {
    return NativeModule.stopEventListener()
  } else {
    return Promise.resolve(false);
  }
}

/*
Cancels active upload by string ID of the upload.

Upload ID is returned in a promise after a call to startUpload method,
use it to cancel started upload.

Event "cancelled" will be fired when upload is cancelled.

Returns a promise with boolean true if operation was successfully completed.
Will reject if there was an internal error or ID format is invalid.

*/
export const cancelUpload = (cancelUploadId: string): Promise<boolean> => {
  if (typeof cancelUploadId !== 'string') {
    return Promise.reject(new Error('Upload ID must be a string'));
  }
  return NativeModule.cancelUpload(cancelUploadId);
}

/*
Listens for the given event on the given upload ID (resolved from startUpload).  
If you don't supply a value for uploadId, the event will fire for all uploads.
Events (id is always the upload ID):
  progress - { id: string, progress: int (0-100) }
  error - { id: string, error: string }
  cancelled - { id: string, error: string }
  completed - { id: string }
*/
export const addListener = (eventType: UploadEvent, uploadId: string, listener: Function) => {
  return DeviceEventEmitter.addListener(eventPrefix + eventType, (data) => {
    if (!uploadId || !data || !data.id || data.id === uploadId) {
      listener(data)
    }
  })
}

export default { startUpload, cancelUpload, addListener, getFileInfo, startEventListener, stopEventListener }