Flash of unstyled content on DSpace 7 homepage

[alanorth]

Describe the bug
I'm not sure if this is "flash of unstyled content" or not, but when you load the DSpace 7 homepage it seems to load, then flashes white, then shows the content. See this demonstration on dspace7.demo.org in Firefox Nightly:

dspace-angular-content-flash.mp4

Is this an issue with all Angular single-page applications or something specific to how we're using Angular? Sorry, I'm not a web developer, but this is surely jarring from a user perspective.

To Reproduce
Steps to reproduce the behavior:

1. Visit https://demo7.dspace.org/

Expected behavior
Web page should not flash a white screen during initial loading, even if it takes a few hundred more milliseconds to download the content.

[alanorth]

Update: for what it's worth, I tried this on a local DSpace 7.1 development instance and the "flash" does not happen. I will close this for now as it must be an issue with the deployment on demo7.dspace.org.

Actually, it seems that it does happen locally, but it's much faster. Opening this again.

[tdonohue]

@alanorth : I think this is a duplicate of #1357, and it's something we're investigating / looking into fixing.

[alanorth]

Thanks, @tdonohue! I searched for a few different descriptions in existing issues but couldn't find anything. Cheers. :)