Memento allows you to implement small pieces of code that use the existing fields as variables, and compute the result based on this data. To do so, add a JavaScript type of field while Creating or Editing the Library, and follow these steps:
- Set the Name for this field
- Arrange the Script that will operate: you can use Field option to add a certain field to this script as a variable, add a JS library, or Test this script. Note, that you can test the script only after its creation
- Set Display options for this field
- Change Advanced parameters if needed: change whether the script should be in the Realtime mode, and set Dependencies if needed
Press Create or Edit to get to the previous menu, and don’t forget to Save the changes.
The detailed information and several useful examples can be found on the wiki.