In order to make it easier to check the changes that have been done in a specific working layer, we would like to be able to get the previous value of a specific attribute so it can be compared in a query. 

I know that we can use the working layer display mode and we are already using the working layer status in a query, but that does not list the value that the attribute has in the layer just above the current one.

Does anyone know of a way to determine that with script function?

One example: Engineer has changed the design pressure of a vessel from 10 barg to 15 barg in a working layer. We want to be able to see both values in one list so we can compare them.

Hi Wouter,

I don't know if I have understood you right, but here is an example for the object-debugger, how you compare the old value with the new one:

Yes, that's exactly the method I was looking for. Added another piece of the puzzle to find the owner of the current working layer, so now it does exactly what I want. 

Thanks a lot for your help!

Hello Jiri,

Can you provide me details of this implementation or show me a way how to do this?

works great if it was changed in the above WL and current, but if not it returns nothing? Why