APLComponent.When has wrong type

[lultimouomo]

APLComponent.When was changed by PR #50 to be a boolean type, but this is not what APL expects. It is a string type that will be evaluated on the device, not on the skill backend.
This is clearly documented here:
https://developer.amazon.com/en-US/docs/alexa/alexa-presentation-language/understand-apl.html#conditional-logic-and-responsive-documents

Using a boolean prevents the device-side evaluation.

[stoiveyp]

@lultimouomo I appreciate you raising the issue. Let me try and clarify.

when is a boolean property, one that determines if the component is to be used in the layout. It can, as with almost all APL properties, use data binding or expressions.

As we have strong typing in .NET, I handle this by making the properties APLValue<T> which gives us the underlying type we're aiming for, but means we can assign an expression as well, using the To method. So in this case

component.When = APLValue<bool?>.To("expression here")

This allows us to disable a component just using false, or as you've seen, use a string.

Hope this clears things up a bit, I'll try and add an example to the readme when I get to my laptop - I won't close the issue until then (on my phone right now) 👍

[stoiveyp]

@lultimouomo I've now updated the readme to mention how expressions and data binding work - I've used the example from the link you sent as that's going to be a really common scenario.