This commit includes several changes to make hashtags work when "lazy
load categories" is enabled. The previous hashtag implementation use the
category colors CSS variables, but these are not defined when the site
setting is enabled because categories are no longer preloaded.
This commit implements two fundamental changes:
1. load colors together with the other hashtag information
2. load cooked hashtag data asynchronously
The first change is implemented by adding "colors" to the HashtagItem
model. It is a list because two colors are returned for subcategories:
the color of the parent category and subcategory.
The second change is implemented on the server-side in a new route
/hashtags/by-ids and on the client side by loading previously unseen
hashtags, generating the CSS on the fly and injecting it into the page.
There have been minimal changes outside of these two fundamental ones,
but a refactoring will be coming soon to reuse as much of the code
and maybe favor use of `style` rather than injecting CSS into the page,
which can lead to page rerenders and indefinite grow of the styles.
We had two issues which were present for a long time I think:
- one that impacts both core discourse and chat. We were not setting top on the header when `footer-nav-ipad` was present, meaning that you could make it scroll under if you try to scroll up by putting your finger on the discourse header
- one that impacted only chat. It's also present in core, but in core it's not a probem because we don't have a fixed height div. The body height was higher than the screen which would cause a second scrollbar to appear and would slightly break layout, if you scroll on this scrollbar (body).
Since https://github.com/discourse/discourse/pull/25501 this behavior was broken. This PR attempts to fix it by being more fine grain.
Also note that this PR is moving `footer-nav-ipad` and `footer-nav-visible` to the `html` element and not the `body`. It makes more sense as we are already adding most of other global state class like `keyboard-visible` to the `html` element.
Tested on:
- chrome desktop
- safari ios - iphone
- PWA ios - iphone
- PWA ios - ipad
- DiscourseHub iphone
This commit sets a default of 0px for `--footer-nav-height` and set it only when `body.footer-nav-visible` allowing us to safely use `--footer-nav-height` wherever it will be needed if set.
