Save Gmail Attachments to Google Drive

GmailToDrive.gs

// GLOBALS
//Array of file extension which you would like to extract to Drive
var fileTypesToExtract = ['zip'];
//Name of the folder in google drive i which files will be put
var folderName = 'Adx Reports';
//Name of the label which will be applied after processing the mail message
var labelName = 'Adx';
//Words contained in the subject of the email
var subjectWording = "Ad Exchange Scheduled Report "


function GmailToDrive(){
  //build query to search emails
  var query = '';
  //filename:jpg OR filename:tif OR filename:gif OR fileName:png OR filename:bmp OR filename:svg'; //'after:'+formattedDate+
  for(var i in fileTypesToExtract){
	query += (query == '' ?('filename:'+fileTypesToExtract[i]) : (' OR filename:'+fileTypesToExtract[i]));
  }
  query = 'in:inbox is:unread subject:' + subjectWording + ' ' + query;
  Logger.log('The query string is:' + query);
  var threads = GmailApp.search(query);
  
  Logger.log('We found '  + threads.length + ' emails for you.');
  
  var label = getGmailLabel_(labelName);
  var parentFolder;
  if(threads.length > 0){
	parentFolder = getFolder_(folderName);
  }
  for(var i in threads){
	var mesgs = threads[i].getMessages();
	for(var j in mesgs){
  	  //get attachments
      var attachments = mesgs[j].getAttachments();
      for(var k in attachments){
    	var attachment = attachments[k];
    	var isZipType = checkIfZip_(attachment);
    	if(!isZipType) continue;
    	
        var attachmentBlob = attachment.copyBlob();
        var file = DriveApp.createFile(attachmentBlob);
        var fileName = getMessageDateStr_(mesgs[j]) + ' ' + file.getName();
        file.makeCopy(fileName, parentFolder);
        file.setTrashed(true);
        Logger.log('File `' + fileName +'` has been uploaded to folder ' 
                   + '`' + parentFolder.getName() +'`');
      }
      mesgs[i].markRead();
	}
	threads[i].addLabel(label);
  }
}

//This function will get the parent folder in Google drive
function getFolder_(folderName){
  var folder;
  var fi = DriveApp.getFoldersByName(folderName);
  if(fi.hasNext()){
    folder = fi.next();
  }
  else{
    folder = DriveApp.createFolder(folderName);
  }
  return folder;
}

// Get a date string in 'yyyymmdd' format
function getMessageDateStr_(message) {
  return message.getDate().toISOString().slice(0, 10).replace(/-/g, '');
}

//getDate n days back
// n must be integer
function getDateNDaysBack_(n){
  n = parseInt(n);
  var today = new Date();
  var dateNDaysBack = new Date(today.valueOf() - n*24*60*60*1000);
  return dateNDaysBack;
}

function getGmailLabel_(name){
  var label = GmailApp.getUserLabelByName(name);
  if(label == null){
	label = GmailApp.createLabel(name);
  }
  return label;
}

//this function will check for filextension type.
// and return boolean
function checkIfZip_(attachment){
  var fileName = attachment.getName();
  var temp = fileName.split('.');
  var fileExtension = temp[temp.length-1].toLowerCase();
  if(fileTypesToExtract.indexOf(fileExtension) != -1) return true;
  else return false;
}