Can't affect UI theme preference

[Ren60FHk]

NetBox version

3.0.8

Python version

3.7

Steps to Reproduce

1. Set the light theme in Profile & Settings.
2. Save changes.
3. Logout.
4. Clear a browser cache.
5. Log in.

Expected Behavior

I expect to see the light theme.

Observed Behavior

The theme is dark.

[jeremystretch]

I'm not able to replicate this in v3.0.8. Do you have your browser configured to prefer dark mode? Maybe try a different browser?

[Ren60FHk]

I've tried another browser before posting - same result. But, I've changed a browser internal theme from dark to light and NetBox had replicated that behaviour. Thus, NetBox leans on the browser (maybe even system for someone) color theme.

[jeremystretch]

I'm not really sure which should take precedence. @thatmattlove any thoughts?

[thatmattlove]

Tricky one. Hopefully a090955 adequately resolves this. The challenge is we have multiple vectors from which to determine the color mode:

1. System/browser preference (prefers-color-scheme media query) — should be considered the lowest priority, since it's inferred and not explicit. ('system mode' below)
2. Mode set by UI toggles (not system preference) — should be considered temporary, not persisted to the user's profile, and not persisted across browser sessions. ('client mode' below)
3. Mode set by system preference — should be persisted in the user's profile and therefore across any of that user's browser sessions. ('server mode' below)

Seems simple on the face, but consider the scenarios:

• System mode is set through inference, client mode is not set, server mode is not set
• System mode is set through inference, client mode is set, server mode is not set — which to use?
• System mode is set through inference, client mode is set, server mode is set, client mode and server mode do not match — which to use?
• System mode is set through inference, client mode is not set, server mode is set

And, consider that these "problems" are presented on each page load and any time a color mode toggle is used.

Ultimately, I implemented the logic as:

1. If the mode was inferred and the server mode is set, use the server mode, overriding the inferred mode.
2. If the client mode is not set and the server mode is, use the server mode, overriding the inferred mode.
3. If the client mode is set and the server mode is not set, use the client mode, but allow it to be overridden if/when a server mode is set (for example, after login).
4. If the client mode is set, and the server mode is set, and they are not the same, use the client mode. This is an assumption on my part that the client mode is more recently set via a toggle.
5. Otherwise, use the inferred mode from the system/browser.
6. As a last resort in the event of an error or no matching conditions whatsoever, use light mode.