Advanced Usage

    This section covers advanced configurations and best practices for using expo-document-scanner in production applications.

    Handling Base64 Responses

    While returning file URIs is the most efficient way to handle large images, sometimes you need the raw base64 data to send directly to an API.

    const scanAndUpload = async () => {
  const result = await scanDocument({
    responseType: 'base64',
    quality: 0.7 // Compress slightly to reduce payload size
  });

  if (result.status === 'success') {
    const base64Images = result.scannedImages;
    
    // Example: send to API
    await fetch('https://api.yourdomain.com/upload', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ images: base64Images })
    });
  }
};

    Warning: Returning base64 strings for high-resolution images can consume significant memory. Always use a lower quality setting if you must use base64, or prefer uploading files directly via their uri using FormData.

    The most memory-efficient way to handle scanned documents is to leave them on the disk and upload them using FormData.

    const result = await scanDocument({ responseType: 'uri' });

if (result.status === 'success') {
  const formData = new FormData();
  
  result.scannedImages.forEach((uri, index) => {
    formData.append(`document_${index}`, {
      uri: uri,
      name: `scanned_${index}.jpg`,
      type: 'image/jpeg',
    } as any); // React Native FormData type workaround
  });

  await fetch('https://api.yourdomain.com/upload', {
    method: 'POST',
    body: formData,
    headers: {
      'Content-Type': 'multipart/form-data',
    },
  });
}

    Error Handling

    Always wrap your scanning logic in a try/catch block, and verify the status of the result. Note that user cancellations are returned as a status: 'cancel' result, rather than throwing an exception.

    Exceptions are only thrown for critical failures, such as missing permissions or underlying native crashes.