From property assignment page , we are unable to assign TOSCA functions to:

• List values
• Map values
• Any property value of a custom datatype

Use of stringbuilder is preferred approach to doing this , but as a temporary measure it would ok to allow the user directly enter the TOSCA function into the value field for string types.

It is possible to use direct entry of YAML with the stringbuilder to assign functions but particularly in the case of complex types, creating the YAML is not a user friendly way of doing it.