How do I get the current instance of “this” file in Google Apps Script?

Question

I'm trying to create a reference to the current DriveApp File object (i.e. the actual Google Drive container for the script itself). Here's what I'm trying to do:

// Assume that thisFile is a FileIterator pointing to THIS file.
// My question in a nutshell: How do I get thisFile?
DriveApp.getFileById( thisFile.getId() );

I want to do this instead of DriveApp.getFileById(id) because I don't want to have to "hard code" the ID string for the script file. That way, if I make a copy of the Google Apps Script project, I don't have to edit anything in the Code.gs or Script Properties. Any suggestions?

Answer 1

If you click on your Apps Script file, open up the details window on the right, and look at the file details for an Apps Script, you'll see a type property. Hover your pointer over the words "Google Apps Script" for the type, and it should show:

application/vnd.google-apps-script

I think you can search files for type. searchFiles(params)

Google Documentation - searchFiles() method

Also see:

Search Parameters

I think you would search by mime-type:

mimeType = 'application/vnd.google-apps-script'

So, you could find all Apps Script files, in the users drive, then if you could set a unique property on the Apps Script file, you could search for that also.

Or search by fullText, which includes the file description, and put a unique description in the file. That way you would be sure to find the apps script file that you created. Then, once search has found the file, you have your reference.

Answer 2

An Apps Script can be standalone or have one of 4 containers (nowadays): Google Sheets, Docs, Forms and Sites. If you know before-hand the type of the container, then it's easy to get its id. e.g.

var id = SpreadsheetApp.getActiveSpreadsheet().getId();
var id = DocumentApp.getActiveDocument().getId();
var id = FormApp.getActiveForm().getId();
var id = SitesApp.getActiveSite().getId();

If you don't know the container type (which would be weird), you could wrap these in various try-catches and find out.

Assuming it's not a Google Site, then you can safely get this id and use it to retrieve the DriveApp File representation of the container.

var file = DriveApp.getFileById(id);

But this file is just an object of the DriveApp API, it's not really a this reference, as in the programming meaning. You could have just as easily used DocsList or advanced Drive service to retrieve a different representation of the same container.

Lastly, I do not know how to grab the id of a standalone script dynamically (from within itself). I suspect it's not possible. But I don't see how that could be useful either. --edit If you want just to copy, why not grab a "fixed" source script directly?