Dependency to make field read-only after add relationships from the subpanel

Let me know if I got the idea:

Parent module has subpanel of module Inventory Management.

Parent module has the field Storage Condition whose value come from field End Condition in related module Inventory Management.

The field Storage Condition on parent module should be readonly if it has been linked a record in subpanel of Inventory Management.

Is that right?

If so then I have some questions:

What should happen if 2 or more records are linked through subpanel Inventory Management? Should Storage Condition on parent module be updated according to latest linked Inventory Management?

I suppose the relationship between parent module and Inventory Management is M:M, right? If so then regular dependencies will not work.

André Lopes said:

The field Storage Condition on parent module should be readonly if it has been linked a record in subpanel of Inventory Management.

Is that right?

Yes, right.

André Lopes said:

What should happen if 2 or more records are linked through subpanel Inventory Management? Should Storage Condition on parent module be updated according to latest linked Inventory Management?

If I have more then one linked record then it will be update according to latest linked Inventory Management.

Relationship is many to many

 You should be able to use Dependencies to make it read-only with the following Sugar Logic formula:

greaterThan(count(inventory_management_relationship_name),0)

You will need to use a different mechanism to get the value from the most recent IM record. Maybe write a new SugarLogic function to get maxRelatedDateValue.