mdk-document-scanner

A NativeScript plugin designed for SAP Mobile Development Kit (MDK) that provides a native document scanning experience on both Android and iOS. The scanned pages are automatically compiled into a single PDF file.

Features

• Android: Uses Google ML Kit Document Scanner (startIntentSenderForResult).
  • No camera permissions required on Android (handled by Google Play Services).
  • Zero-configuration UI.
• iOS: Uses VisionKit (VNDocumentCameraViewController).
  • Native "Notes-like" scanning experience.
• Output: Generates a high-quality PDF from the scanned images.
• Lightweight: Uses platform-native PDF generation (android.graphics.pdf and PDFKit), avoiding heavy JavaScript PDF libraries.

Requirements

• Naivescript: 8.0+
• Android Runtime: 8.8.0+ (Requires Java 17 support)
• iOS: 13.0+

Installation

npm install mdk-document-scanner

Setup & Permissions

Android

No specific permissions are required in AndroidManifest.xml as ML Kit handles the camera interaction internally via Google Play Services.

iOS

You must add the camera usage description to your Info.plist:

<key>NSCameraUsageDescription</key>
<string>We need access to the camera to scan documents.</string>

Usage in SAP MDK

This plugin is designed to be easily called from an MDK JavaScript Rule.

1. Create a new Rule, e.g., Rules/ScanDocument.js.
2. Import and call the function.

import { scanAndGeneratePDF } from "mdk-document-scanner";

/**
 * Describe this function...
 * @param {IClientAPI} clientAPI
 */
export default function ScanDocument(clientAPI) {
  // Optional: Show loading indicator
  clientAPI.showActivityIndicator("Scanning...");

  return scanAndGeneratePDF(clientAPI)
    .then((pdfPath) => {
      clientAPI.dismissActivityIndicator();
      console.log("PDF generated at: " + pdfPath);

      // Example: Return the path or display a success message
      return clientAPI.executeAction({
        Name: "/MyApp/Actions/ShowSuccess.action",
        Properties: {
          Message: "Scan Complete! PDF saved at: " + pdfPath,
          Duration: 4000,
        },
      });
    })
    .catch((error) => {
      clientAPI.dismissActivityIndicator();
      console.error("Scan Error: " + error);

      return clientAPI.executeAction({
        Name: "/MyApp/Actions/ShowError.action",
        Properties: {
          Message: "Scan failed: " + error,
        },
      });
    });
}

API

scanAndGeneratePDF(clientAPI: any): Promise<string>

• clientAPI: The MDK Client API object (passed for context, though primarily used for Android Activity resolution).
• Returns: A Promise that resolves to the absolute file path of the generated PDF string.

Troubleshooting

Android: "ClassNotFoundException"

If you encounter runtime errors on Android regarding missing classes, ensure your application includes the ML Kit dependency. Most standard MDK clients include Play Services, but if you are building a custom client, ensure:

dependencies {
  implementation 'com.google.android.gms:play-services-mlkit-document-scanner:16.0.0-beta1'
}

Android: "Failed resolving method startActivityForResult"

This plugin uses Java Reflection to call startIntentSenderForResult on the Activity. This is intentional to bypass known issues with NativeScript's matching of method overloads on androidx.activity.ComponentActivity. Do not modify the reflection logic unless you are sure of the runtime implications.