React Native Document Scanner

This fork includes the androidScannerMode option, based on PR #150 but adapted for the latest version of the plugin.

This is a React Native plugin that lets you scan documents using Android and iOS. You can use it to create apps that let users scan notes, homework, business cards, receipts, or anything with a rectangular shape.

| iOS | Android | | -------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | | |

Install

npm install react-native-document-scanner-plugin

After installing the plugin, you need to follow the steps below

iOS

1. iOS requires the following usage description be added and filled out for your app in Info.plist:

• NSCameraUsageDescription (Privacy - Camera Usage Description)

2. Install pods by running

cd ios && pod install && cd ..

Android

Note: You don't need to prompt the user to accept camera permissions for this plugin to work unless you're using another plugin that requires the user to accept camera permissions. See Android Camera Permissions.

Examples

• Basic Example
• Limit Number of Scans

Basic Example

import React, { useState, useEffect } from 'react'
import { Image } from 'react-native'
import DocumentScanner from 'react-native-document-scanner-plugin'

export default () => {
  const [scannedImage, setScannedImage] = useState();

  const scanDocument = async () => {
    // start the document scanner
    const { scannedImages } = await DocumentScanner.scanDocument()
  
    // get back an array with scanned image file paths
    if (scannedImages.length > 0) {
      // set the img src, so we can view the first scanned image
      setScannedImage(scannedImages[0])
    }
  }

  useEffect(() => {
    // call scanDocument on load
    scanDocument()
  }, []);

  return (
    <Image
      resizeMode="contain"
      style={{ width: '100%', height: '100%' }}
      source={{ uri: scannedImage }}
    />
  )
}

Here's what this example looks like with several items

Limit Number of Scans

You can limit the number of scans. For example if your app lets a user scan a business card you might want them to only capture the front and back. In this case you can set maxNumDocuments to 2. This only works on Android.

import React, { useState, useEffect } from 'react'
import { Image } from 'react-native'
import DocumentScanner from 'react-native-document-scanner-plugin'

export default () => {
  const [scannedImage, setScannedImage] = useState();

  const scanDocument = async () => {
    // start the document scanner
    const { scannedImages } = await DocumentScanner.scanDocument({
      maxNumDocuments: 2
    })
  
    // get back an array with scanned image file paths
    if (scannedImages.length > 0) {
      // set the img src, so we can view the first scanned image
      setScannedImage(scannedImages[0])
    }
  }

  useEffect(() => {
    // call scanDocument on load
    scanDocument()
  }, []);

  return (
    <Image
      resizeMode="contain"
      style={{ width: '100%', height: '100%' }}
      source={{ uri: scannedImage }}
    />
  )
}

Documentation

• scanDocument(...)
• Interfaces
• Enums

scanDocument(...)

scanDocument(options?: ScanDocumentOptions | undefined) => Promise<ScanDocumentResponse>

Opens the camera, and starts the document scan

| Param | Type | | ------------- | ------------------------------------------------------------------- | | options | ScanDocumentOptions |

Returns: Promise<ScanDocumentResponse>

Interfaces

ScanDocumentResponse

| Prop | Type | Description | | ------------------- | --------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- | | scannedImages | string[] | This is an array with either file paths or base64 images for the document scan. | | status | ScanDocumentResponseStatus | The status lets you know if the document scan completes successfully, or if the user cancels before completing the document scan. |

ScanDocumentOptions

| Prop | Type | Description | Default | | ----------------------- | ----------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------- | | croppedImageQuality | number | The quality of the cropped image from 0 - 100. 100 is the best quality. | : 100 | | maxNumDocuments | number | Android only: The maximum number of photos an user can take (not counting photo retakes) | : undefined | | responseType | ResponseType | The response comes back in this format on success. It can be the document scan image file paths or base64 images. | : ResponseType.ImageFilePath | | androidScannerMode| AndroidScannerMode | Android only: The scanner mode to use. | : AndroidScannerMode.ScannerModeFull |

Enums

ScanDocumentResponseStatus

| Members | Value | Description | | ------------- | ---------------------- | --------------------------------------------------------------------------------------------------------- | | Success | 'success' | The status comes back as success if the document scan completes successfully. | | Cancel | 'cancel' | The status comes back as cancel if the user closes out of the camera before completing the document scan. |

ResponseType

| Members | Value | Description | | ------------------- | ---------------------------- | ------------------------------------------------------------------------------- | | Base64 | 'base64' | Use this response type if you want document scan returned as base64 images. | | ImageFilePath | 'imageFilePath' | Use this response type if you want document scan returned as inmage file paths. |

AndroidScannerMode

| Members | Value | Description | | --------------------------- | ----- | ----------- | | ScannerModeFull | 1 | The full scanner capabilities. | | ScannerModeBaseWithFilter | 2 | Base scanner functionality with filter support. | | ScannerModeBase | 3 | Base scanner functionality. |

Expo

This plugin doesn't run in Expo Go. It works with Expo, and you can avoid manually changing iOS and Android files by following these steps.

npx expo install react-native-document-scanner-plugin

Add react-native-document-scanner-plugin to plugins in app.json or app.config.json.

{
  "name": "my expo app",
  "plugins": [
    [
      "react-native-document-scanner-plugin",
      {
        "cameraPermission": "We need camera access, so you can scan documents"
      }
    ]
  ]
}

npx expo prebuild

or

eas build

Common Mistakes

• Android Camera Permissions

Android Camera Permissions

You don't need to request camera permissions unless you're using another camera plugin that adds <uses-permission android:name="android.permission.CAMERA" /> to the application's AndroidManifest.xml.

In that case if you don't request camera permissions you get this error Error: error - error opening camera: Permission Denial: starting Intent { act=android.media.action.IMAGE_CAPTURE

Here's an example of how to request camera permissions.

import React, { useState, useEffect } from 'react'
import { Platform, PermissionsAndroid, Image, Alert } from 'react-native'
import DocumentScanner from 'react-native-document-scanner-plugin'

export default () => {
  const [scannedImage, setScannedImage] = useState();

  const scanDocument = async () => {
    // prompt user to accept camera permission request if they haven't already
    if (Platform.OS === 'android' && await PermissionsAndroid.request(
      PermissionsAndroid.PERMISSIONS.CAMERA
    ) !== PermissionsAndroid.RESULTS.GRANTED) {
      Alert.alert('Error', 'User must grant camera permissions to use document scanner.')
      return
    }

    // start the document scanner
    const { scannedImages } = await DocumentScanner.scanDocument()
  
    // get back an array with scanned image file paths
    if (scannedImages.length > 0) {
      // set the img src, so we can view the first scanned image
      setScannedImage(scannedImages[0])
    }
  }

  useEffect(() => {
    // call scanDocument on load
    scanDocument()
  }, []);

  return (
    <Image
      resizeMode="contain"
      style={{ width: '100%', height: '100%' }}
      source={{ uri: scannedImage }}
    />
  )
}