File.md5Checksum equivalent for Google Doc files

Question

For non-Google Doc files in a Google Drive, I can detect a change by comparing the File.md5Checksum with a previous value.

md5Checksum is null for Google Doc files:

 application/vnd.google-apps.*

Is there any method besides File.modifiedDate?

Admittedly, it's sort of a corner case: if a doc goes from state A => B => A, then the modifiedDate will change but not the content.

Answer 1

File.modifiedDate is definitely a good solution but you should consider using the Changes feed to detect changes to file:

https://developers.google.com/drive/manage-changes

Once you retrieve the Changes feed, you can filter the entries using the fileId field.