How can I discriminate between file and folder in DriveApp using GAS

Question

I know a folder actually is a file with a special mimeType application/vnd.google-apps.folder in Google Drive. But documentation about DriveApp Folder class doesn't contain a method getMimeType() like DriveApp File class does.

How can find out in a function if an argument of that function refers to a folder or to a (normal) file?

function displayResults(fileOrFolder)
{
  var id   = fileOrFolder.getId();
  var name =  fileOrFolder.getName();

  var mimeType = fileOrFolder.getMimeType();  // works if file; error if folder

  if (fileOrFolder == <Class File>)
  {
     <do something>
  }
  else if (fileOrFolder == <Class Folder>)
  {
     <do something else>
  }
}

Zig Mandel · Accepted Answer · 2014-06-26T15:47:39.280

2

Look if the method exists. If obj.getMimeType===undefined its a folder.
or, to make it more robust in case the api changes (adds the method to folders), use
if (obj.getMimeType===undefined || obj.getMimeType.toLowerCase() =="application/vnd.google-apps.folder")

edited Jun 26 '14 at 15:47

answered Jun 25 '14 at 13:04

Zig Mandel

19,571
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never too careful ;) +1 for exhaustivity . – Serge insas Jun 26 '14 at 16:13
I'm sorry but it doesn't work. Actually using getMimeType() was what I tried myself (see code in my answer) – SoftwareTester Jun 27 '14 at 07:00
nop, its not getMimeType(), its getMimeType. See the code, copy and paste it. – Zig Mandel Jun 28 '14 at 02:43

Serge insas · Answer 2 · 2014-06-27T09:04:53.567

0

I don't understand why you say that Zig's answer does not work... All the tests I made were positive.

example of how I tested it (test ID are shared publicly and so should work for anybody):

function test(){
  var item = DriveApp.getFileById('0B3qSFd3iikE3MS0yMzU4YjQ4NC04NjQxLTQyYmEtYTExNC1lMWVhNTZiMjlhMmI');
  testDriveFolders(item);
  var item = DriveApp.getFileById('1fXxLHuDlySZ6rOQjTsZdUl6rnw14sa17Q0ZTZ0HoGk1jbuHX-eLq1dyf');
  testDriveFolders(item);
}

function testDriveFolders(obj){
  try{var mimeType = obj.getMimeType()}catch(e){mimeType = 'folder'};
  var name =  obj.getName();
  if (mimeType =="application/vnd.google-apps.folder" || mimeType == 'folder'){
    Logger.log(name+' is a folder');
  }else{
        Logger.log(name+' is of the type '+mimeType);
  }
}

edited Jun 27 '14 at 09:04

answered Jun 27 '14 at 08:57

Serge insas

45,904
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No need for try/catch. In the code i provided i do Not call getMymeType(), i do obj.getMimeType===undefined which is very different. Is checking for existance of the function, not calling it (until later) – Zig Mandel Jun 27 '14 at 13:12
Yes indeed, I used it making a mix of the other post and yours because I started by testing his code (that was said "not working"). In the end both methods seems useable... – Serge insas Jun 27 '14 at 14:26
1

yes sorry I wasnt complaining about this approach, just pointing out why hes try at it wasnt working. try/catch in general is not the best idea because methods could throw genuine error exceptions and not just language exceptions about the method not existing. – Zig Mandel Jun 27 '14 at 14:31

score 0 · Answer 3 · answered Feb 15 '16 at 13:56

0

Get the file object associated to the ID. getMimeType() will work:

var mt = DriveApp.getFileByID(fileOrFolder.getId()).getMimeType();
if (mt == MimeType.FOLDER) {
  // it's a folder
} else {
  // it's a file.
}

answered Feb 15 '16 at 13:56

Rafael

11
3

How can I discriminate between file and folder in DriveApp using GAS

3 Answers3

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