Cover block overlay with detected color does not work once saved

[richtabor]

The current functionality for detecting dominant color and applying it to the cover block's overlay is nice, but it's limited—making it feel inconsistent.

The cover block has the isUserOverlayColor attribute, which when set to true does not detect color and apply a new customOverlayColor.

I propose that this value should only be true if the user actually picked a different color than what was detected and applied.

If I never changed the previously generated overlay color value, and I replaced the image, I'd expect the block to detect and apply the new image's dominant color to the overlay again. This works today — but again, only if I don't save the post. Once it's saved, isUserOverlayColor is no longer false and you're stuck with the previously saved overlay color unless you manually change it.

Related #54054.

Visual

CleanShot.2024-08-21.at.20.55.50.mp4

[andrewserong]

Interesting bug! I'm not sure of a solution yet, but while testing this out, I found that if I comment out this line from the last deprecation for the block, then replacing the image after reloading the post works again to update the cover overlay color:

gutenberg/packages/block-library/src/cover/deprecated.js

Line 410 in c566725

isUserOverlayColor: true,

This points to that deprecation's migrate function running on newly saved post content, which I think it probably shouldn't be. We'll likely need to dig into that deprecation's logic a little further to see why it's firing when it shouldn't.

[andrewserong]

Just assigning this one to myself since I've started looking into it, but anyone else is welcome to look, too, of course! 🙂

[Mamaduka]

@andrewserong, the new deprecation seems to be broken. See #64480 (comment).

[andrewserong]

I have a tentative fix open over in #65077 that's proposing removing the deprecation. Very happy for feedback on it, either way!

[andrewserong]

I've opened an alternative fix over in #65105. Thanks to @ajlende for the guidance!