Encapsulate traits for reusability

[membla]

I have a number of traits that can be applied to a number of components. For some of these traits their values affect other properties of the component, so a kind of computed state. I'd believe this is not a completely uncommon use case.

I'm now thinking about what the best way to encapsulate these traits would be – while the setValue() / getValue() on TraitProperties seem like ideal candidates the fact that they are not called when the initial value is fetched still forces me to use the init() on the component to set the initial values of the computed state properties. I then would need to extend the init() for each trait I want to add to a component which feels very convoluted.

Am I missing something that would let me fully encapsulate a trait that needs to keep other properties in sync with the current API?

[artf]

From what I remember calling custom getValue from the beginning might generate loops in some cases (don't remember which ones though) but I think we could allow this to be controlled with some additional property. Would that solve your use case?

[membla]

Right, I think I can see how that could happen. But yes, having getValue() always called when accessing the value I believe would allow for a much better encapsulation of traits.