The contrast checker should be triggered when colors are changed.

[juanfra]

What problem does this address?

While working on TT5, I noticed that the contrast checker only runs when you change the block focus. This means if you’re adjusting colors for a block, the contrast issue message only appears after you switch to another element and then come back to the block controls. As a result, many users might miss the contrast warning entirely, defeating its purpose.

At the same time, the notice is still there when you update colors that would pass the contrast checker (for the same reason).

Screen.Recording.2024-11-15.at.15.21.25.mov

What is your proposed solution?

It would be ideal if the notice updated in real-time with color changes, providing a clear message for the current color selection.

[Mamaduka]

Here's a similar report, #60825. The cause might be the same, or the previous bug might have evolved 🐛

[juanfra]

Thank you, George! Apologies for not catching that earlier. The issue does seem very similar, if not identical. It’s possible it evolved, as it wasn’t working for me at all—not even on a second attempt.

[Mamaduka]

No worries, @juanfra!

I think the bug described in the old issue is no longer reproducible after #63799. It introduced the dependencies to contrast the checker effect, so it no longer runs on every render, as the top comment suggests.

[afercia]

so it no longer runs on every render

@Mamaduka does that mean #63799 made things worse, in a way? If so, this issue should be marked as a regression.

In general, the contrast checker not being reliable is a long standing issue that originates even before the original report on #60825. I would greatly appreciate some more priority on reviewing the contrast checker implementation. Ideally, there should be a solid mechanism to signal to other components when the block colors have been changed.

I would love to see this considered under an architectural perspective. On #33079 there's an ongoing conversation about a similar issue, where other components and plugins need to know when a block content has been updated. Similarly, I'd tend to think other components and plugins need to know when a block attributes have been updated. Cc @WordPress/gutenberg-core