Just Another Frustratingly Simple Issue - Setting An Input Property

[MCrawley2]

Scenario:

1. MyCustomRadioInput is a custom component and has an input property named ShowErrorMessage which is a boolean - The default is false.
2. Inside MyCustomRadioInput is also a Label who's visiblity is bound to the ShowErrorMessage custom property.
3. On click of a button outside of MyCustomRadioInput I change ShowErrorMessage to true.
4. The Notify immediately afterwards still shows false.
5. The internal label that is bound to ShowErrorMessage does not react, presumably because the input property is not changing.

PowerFX example - Button.OnSelect:

MyCustomRadioInput.ShowErrorMessage = true;
Notify(RadioInput_1.ShowErrorMessage);

This seems like basic functionality for what MSPP is trying to provide for its "citizen developers" so why doesn't this work?

A fuller context:
I need to display a Label which is a child of MyCustomRadioInput when Button1 is clicked. I'm aware I can do mostly whatever I want within the context of MyCustomRadioInput itself but that's not what we need and we have a strict design system dictating how user interactions should work due to working in Gov.

I have literally gone around in circles for days with different scenarios, including developing PCF's which of course have their own limitations (in particular the lack of ability to execute PowerFX).

[TheRobRush]

Unless I am reading your post wrong, your issue lies in that you are trying to reference a variable set outside your component. Since components are designed to be portable, from one app to another, you cannot reference things that are specific to one app (global variables, screen names, etc.) with them.  Are you intending to create a single component you can reuse in multiple apps? If not, I would build this functionality without a custom component.

[MCrawley2]

We're not referencing a variable, we're referencing a custom input property which I would have thought would be fine - It 100% exists in the context of the library component so there shouldn't be any issues with portability. It still doesn't make sense why this is an issue to me.

Regarding your question regarding re-usable components, we have strict design guidelines so the only way we can use MSPP in our org is to provide our users with pre-built component to avoid duplication of work and keeping things consistent. We couldn't expect our users to create the complex components we need, unfortunately, due to the features those components need as per our design guidelines.