How do I recursively access PDF files in Google Drive folders and convert them all to Google Doc?

Question

I have a large number of PDF files split across multiple folders (in a tree structure) in my Google Drive. I'd like to retain the PDF files while also creating a copy of each PDF document in Google Docs format which has been OCRd. The Google Docs file needs to have the same name as the PDF file.

How do I do this?

As part of this, I tried to at least convert one file into PDF by code but ran into issues there as well.

function pdfToDoc() {  
 var fileBlob = DriveApp.getFileById('<ID>').getBlob();  
 var resource = {
   title: fileBlob.getName(),
   mimeType: fileBlob.getContentType()
 };
 var options = {
   ocr: true
 };
 var docFile = Drive.Files.insert(resource, fileBlob, options);   // <-- Google said "Empty response (line 10, file "Code")"
 Logger.log(docFile.alternateLink);  
}

Answer 1

I followed this tutorial but made some changes because I'm using v3 of Drive API. Here is the snippet:

var blob = DriveApp.getFileById('FILE_ID').getBlob();
Logger.log(blob)
  var text = pdfToText(blob, {ocrLanguage: "en"});
  Logger.log(text);


/**
 * Convert pdf file (blob) to a text file on Drive, using built-in OCR.
 * By default, the text file will be placed in the root folder, with the same
 * name as source pdf (but extension 'txt'). Options:
 */

function pdfToText ( pdfFile, options ) {

  // Ensure Advanced Drive Service is enabled
  try {
    Drive.Files.list();
  }
  catch (e) {
    throw new Error( "Enable 'Drive API' in Resources - Advanced Google Services." );
  }


  // Prepare resource object for file creation
  var parents = [];
  var pdfName = "Sample Docs";
  Logger.log(pdfName)
  var resource = {
    name: pdfName,
    mimeType: MimeType.GOOGLE_DOCS,
    parents: parents
  };

  // Save PDF as GDOC
  resource.title = pdfName.replace(/pdf$/, '');
  var insertOpts = {
    'ocr': true,
    'ocrLanguage': 'en'
  }
  Logger.log(resource.title)
  var gdocFile = Drive.Files.create(resource, pdfFile, insertOpts);

  // Get text from GDOC  
  var gdocDoc = DocumentApp.openById(gdocFile.id);
  var text = gdocDoc.getBody().getText();

  // Save text file, if requested
  resource.name = pdfName.replace(/pdf$/, 'txt');
  resource.mimeType = MimeType.PLAIN_TEXT;

  var textBlob = Utilities.newBlob(text, MimeType.PLAIN_TEXT, resource.name);
  var textFile = Drive.Files.create(resource, textBlob);

  return text;
}

Initially, DriveApp cannot convert pdf to Google Docs directly so I used Advance Drive Service. Just follow this link on how to enable advanced services .

Hope this helps.