[Stretch] Investigate how to prevent component initialisation based on a condition

[romaricpascal]

What

Investigate how to prevent component initialisation based on a condition, like Analytics needing users to have accepted cookies on the Design System site.

Why

This would offer a consistent way to initialise components that require a little check before actually being initialised, without having to actually instantiate them.

Who needs to work on this

Developers

Who needs to review this

Developers

Done when

• We've designed the feature
• We've implemented the feature
• We've documented the feature

[romaricpascal]

This would provide a clear point for checking the presence of specific APIs, like in the Copy component of the Design System.

[romaricpascal]

Having a separate method to check if specific APIs are supported overlaps a lot with isSupported, made @protected in #5323. We've decided to merge the two approaches and make checkSupport static and protected, which will allow it to:

• be called by createAll ahead of looping on all components, saving unnecessary looping
• be overridden by child classes if a component or components have other conditions to check, like the availability of an API.

Child classes overriding the method will be able to throw whatever Error they see fit when support is not available for the component, which:

• reduces the logistics the base class needs to be responsible for
• allows child classes to send a custom message
• will fit into createAll's way of catching these errors during initialisation
• makes use of JavaScript's native capabilities for throwing errors rather than returning a boolean, then having the base class throw an error.