fxLayoutGap not allows working on resize

[tmburnell]

Bug, feature request, or proposal:

If you load the page with an element hidden then resize to where it is visible the gap is not calculated (leaving no space). Where if the page is loaded where it is visible you can resize all you want and the gap displays correctly.

What are the steps to reproduce?

Providing a StackBlitz (or similar) is the best way to get the team to see your issue.

• https://stackblitz.com/edit/angular-flex-layout-seed-v5tsns?file=app/test.component.ts

What is the use-case or motivation for changing an existing behavior?

So it appears that the gap is only calculated on init of the page, and not on the change event. This might have been done for performance ... but leaves for inconstant ui.
Or it was just overlooked.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

Angular: 5.2.0
flex-layout: 2.0.0-beta.12

*** Amended ***
I noticed one more thing after trying to make the colors more visible:
when i said if the page loads where the content is visible, the gap stays even after the element hides (which seems like a related bug ... because it should go away).

[CaerusKaru]

Ok this is definitely an issue, and it stems from the fact that most directives either watch for internal changes or layout direction changes (e.g. row->column) only.

This will require some careful design to get right, but the issue you identified (in both cases) is real and we're investigating.