Tip #69 | Default Implementation for AL Interfaces

I just love it when I get an error and nothing I search for answers what to do next.

Like this one

Value ' ' does not implement interface 'ForNAV Layout' and there is no default implentation for the mentioned interface.AL(AL0596)

There is no mentioning of default implementations in the Microsoft documentation.

And in fact, in this enum value, I do want a default implementation since “Empty” is a fallback since I want to use the new expandable and collapsable row feature in BC16.

The solution: this is a property on Enum level

The motivation here for me to work with an Enum and an Interface is that we have a partner that want’s to implement a feature called “multiple layouts” that we think does not fit with the simplicity we have in mind for our core product.

This allows the partner to create a new App in AppSource with a dependency on ForNAV that introduces new features that only a subset of our customers need.

The majority of our customers is not burdoned with unnessesairy complexity while the few who need it have a solution they can subscribe to.

That my friends is what we mean with Extendability by design.