react-native-document-scan v1.0.13

React Native Document Scanner

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

Android

Install

npm install react-native-document-scanner-plugin

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

Android

1. Open android/gradle.properties and add org.gradle.jvmargs=-Xmx2048m

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
• Remove Cropper

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

This only works on Android.

1.34-alpha add a minNumDocuments attribute, to do not show done button if min is not reached.

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.

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 }}
    />
  )
}

Remove Cropper

You can automatically accept the detected document corners, and prevent the user from making adjustments. Set letUserAdjustCrop to false to skip the crop screen. This limits the max number of scans to 1. 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({
      letUserAdjustCrop: false
    })
  
    // 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

Returns: Promise<ScanDocumentResponse>

Interfaces

ScanDocumentResponse

ScanDocumentOptions

Enums

ScanDocumentResponseStatus

ResponseType

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 }}
    />
  )
}

License

Copyright 2022 David Marcus

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.