mdcFoundation should be initialised before firstUpdated

[elyobo]

Delaying mdcFoundation instantiation until firstUpdated (see base-element) means that any other methods which rely on the foundation (e.g. opening a snackbar) will fail.

Is there a reason it's deferred instead of simply running in the constructor?

[Westbrook]

Being LitElement renders async waiting for firstUpdated (which is triggered via code paths initiated in the constructor) is the way to ensure component DOM is available when mdcFoundation is run against the element. If the element didn't wait and then tried to open a snackbar before firstUpdated it wouldn't really be there to open.

You can see the code path from constructor to initialize to _requestUpdate to _requestUpdate to _enqueueUpdate to performUpdate to firstUpdated in https://github.com/Polymer/lit-element/blob/master/src/lib/updating-element.ts to better understand the piping here.

[elyobo]

Thanks for the explanation and pointer to the relevant code; odd that the initialisation is async when DOM manipulation is sync.

Perhaps attempts to perform actions before a component is ready should queue actions and then handle them on firstUpdate when it's safe to do so instead? I'm not familiar with the code at all yet, so not sure whether that makes practical sense or where it should go (e.g. instantiate mdc foundation in constructor instead and have it handle queueing, then flush the queue on firstUpdate maybe?)

[elyobo]

Thanks @azakus!