I saw art with tags I have blacklisted

I recently found out I can blacklist tags so decided to do it and add a bunch of them. I was thinking like "wait, can I add as many as I want? This is too good to be true!", and it sure was! I just clicked on a character tag, and saw art of it with my blacklisted tags. To be precise, I saw it for 1sec and then it disappeared, but I still saw it, unfortunately. You may say I'm nitpicking, or something, but believe it or not, I don't want to see art of characters I like with my blacklisted tags for even a single second.
I don't know if this is an actual bug or what, but is there any chance this will be fixed? Genuinely pissed me off, especially since I was happy cause I thought this site will be more bearable after I blacklist some tags.

AFAIK this is just how danbooru works, like most websites do with style loading. Not sure if it's javascript or css or both or a secret third thing, but this happens with other websites too—gotta think a bit before page is fully loaded. Basically the blacklisted posts are still queried but are hidden after a moment or two of page loading. Don't think it really can be "fixed".

I noticed the same problem too, and I do think this is something that should be fixed. I don't really know how the site works on that technical of a level, but I would assume it would be more efficient to apply the blacklist to thumbnails before displaying them.

In the meantime, maybe you could try checking your memory usage during those times? If it's high, I'd imagine it would slow down the page loading enough for the thumbnails to show up.

I don't think it's that serious, you probably couldn't even see the thumbnail of those posts fast enough before they got hidden. Not worth getting too upset about a blacklisted post flickering on your screen - I can think of other cases where a post you probably don't want to see ends up staying on your screen, up to and including the initial uploader forgetting some tags and it stays like that for hours (particularly any of the censored tags).

This isn't a bug, it's just something that's part of how the site loads pages. Posts loading and pagination is server-side, blacklist is client-side.

Add this to your custom CSS:

.post-preview:not(.blacklisted) {
    display: none;
}

(.blacklisted in this context does not actually means "blacklisted", but processed by blacklist whether it should be hidden or not)

WRS said:

I don't think it's that serious, you probably couldn't even see the thumbnail of those posts fast enough before they got hidden. Not worth getting too upset about a blacklisted post flickering on your screen - I can think of other cases where a post you probably don't want to see ends up staying on your screen, up to and including the initial uploader forgetting some tags and it stays like that for hours (particularly any of the censored tags).

This isn't a bug, it's just something that's part of how the site loads pages. Posts loading and pagination is server-side, blacklist is client-side.

WaifuMaster9000 just said they saw the image. I don't see any reason to question this.

If a feature isn't working the way it's supposed to, then it's a bug, end of story. Whether it's worth putting in the necessary effort to fix it, which might include restructuring the site, is another matter. Thankfully, we can use custom CSS to work around some of these issues for the time being.

I see the thumbnails flicker all the time too. Just because the known function of blacklisting is to hide posts, doesn't mean that them flickering is a bug. It could be that way for any number of reasons including a technical limitation or intentional implementation (e.g. to keep the speed of the client-facing application, things like hiding are applied after the server has responded to the client's request to load a page and has displayed the posts, like a post-processor).

A bug would be if the blacklist function was not hiding the posts even after applying the tags, which is not the case here. What's happening here shouldn't be confused for a bug because it's not breaking the functionality of blacklisting, it's instead a matter of its implementation.

ETA: I stand corrected: issue #3816. In this case it actually is one per this. Just that not all cases of jank like this should be chalked up to being a bug.

I just realized that I didn't consider the fact that blacklists can be toggled on and off without refreshing the page. In that case, it might be easier to program it so the images are loaded before the blacklist is applied. Maybe the same line of code that loads the image also displays it. If it didn't, there might be some delay in toggling the blacklist off for the first time so the unloaded thumbnails could be loaded. I still think that would be preferable to the current version that relies on the processing speed being fast enough to hide the already loaded images before they can be seen.

Do note that even though the blacklist implementation leaves a bit to be desired, in the end you're still reliant upon correct tagging, which won't always be the case.