I would to have a "comments" field on a node and track when that specific field was last updated. There are reasons that the node might be updated, without updating that specific field. I want to know how recently that specific field was updated.

I will want to display the information on the node. Something to the effect of "this field was last updated on -- / -- / --. 

I'm working on a new module to do this. I could not find an existing module that does this. But, if there is a module that does this OR one where it might make sense to add this functionality, let me know. 

I did consider making the field a custom entity and making it a node reference field. But, I think a contrib module that does this would be much easier.

Comments

Here is a sample module that does the required task. 

https://github.com/stpaultim/field_change_log

I'm still working on it and testing it. But, initial tests are good. 

Still open to finding out that there are already modules that do this - or that there is an existing module that maybe could use this functionality. 

It seems very niche to have this in it's own module.

Did you forget to add a link?