This commit includes various accessibility improvements for the new user menu:
* Add `title` attributes to the user menu tabs
* Properly label lists (by adding `aria-labelledby` to `<ul>` elements) for screen readers
* Change the user menu structure so that the tabs come before the content panel in the DOM, but use CSS to reverse them visually.
Normally, changing the order of elements via CSS is bad for accessibility, but I believe this is one of the rare scenarios where it [makes sense](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Ordering_Flex_Items#use_cases_for_order). Prior to this change, if you want to reach the first notification item after you select a tab using the keyboard, you have to hit <kbd>ctrl</kbd>+<kbd>tab</kbd> because the notifications list is before the tabs list. However, with this change, <kbd>tab</kbd> will move you to the first item in the list after you select a tab using your keyboard.
* Aria-hide the unread notifications badge/count on the tabs because the `title` attribute on the tab indicates the unread count.
* Add some tests.
In itself, this change will not cause tests to run in parallel. It just unlocks the ability to use tools like `ember exam` to run tests in parallel. For example:
```
yarn ember exam --load-balance --parallel=3 --random
```
We previously had a system which would generate a 10x10px preview of images and add their URLs in a data-small-upload attribute. The client would then use that as the background-image of the `<img>` element. This works reasonably well on fast connections, but on slower connections it can take a few seconds for the placeholders to appear. The act of loading the placeholders can also break or delay the loading of the 'real' images.
This commit replaces the placeholder logic with a new approach. Instead of a 10x10px preview, we use imagemagick to calculate the average color of an image and store it in the database. The hex color value then added as a `data-dominant-color` attribute on the `<img>` element, and the client can use this as a `background-color` on the element while the real image is loading. That means no extra HTTP request is required, and so the placeholder color can appear instantly.
Dominant color will be calculated:
1. When a new upload is created
2. During a post rebake, if the dominant color is missing from an upload, it will be calculated and stored
3. Every 15 minutes, 25 old upload records are fetched and their dominant color calculated and stored. (part of the existing PeriodicalUpdates job)
Existing posts will continue to use the old 10x10px placeholder system until they are next rebaked
Upgrading to Markdown.it v13 broke empty inline BBCodes. This works around the problem by adding an empty token before a closing token if the previous token was a BBCode token.
It also removes the unused `jump` attribute which was removed in Markdown.it v12.3
The experimental user menu has a tab that displays recent reviewables and at the moment when a new signs up for the site and they need to be approved, admins see a very scary "suspicious user" copy in the reviewables tab in the user menu. We don't need the copy to be very scary because when a user needs to be approved, it's because the site operator has configured the site to force all new users to go through the review queue and it's not some kind of spam detector flagging the user.
The key fix in this commit is that it removes `this.replaceState(path)` for anchor-only URLs. We still intercept those routing changes to properly calculate the scroll position of the anchor via `jumpToElement`, but we no longer use the Ember router to override the browser's history. This fixes the subfolder issue and also lets the browser maintain its history correctly.
The commit also includes a small refactor to the `jumpToElement` helper to facilitate stubbing in tests.
Secure media requests go through the app. In topics with many images, this makes it very easy to hit rate limiters. Skipping the low-res placeholders reduces the chance of this problem occuring.
Reverts #18241 and fixes issues with the original PR:
1. Remove an extraneous `margin-left: auto` from a grid cell (this was causing the buggy behavior in webkit)
2. Add `grid-area` name to `.extra-info-wrapper`
3. Account for `.wrap` padding
4. Remove unused css (`.header-row` and inner styles)
This PR restores a small feature which was present in the old menu and allowed users to click on the active tab in the menu to navigate to some page that showed the same items in the menu but with more details.
For example, if you switch to the PMs tab and then click on it again, currently nothing happens. However, with this change, clicking on the tab again will take you to your messages page at `/my/messages`.
Note: plugins that register custom tabs in the menu can provide a `linkWhenActive` property for their tab if they wish to mimic core's tabs, but it's optional; if they don't provide one, the tab will do nothing if the user clicks on it again.
Internal topic: t/73349.
Because Discourse is a single-page application, clicks on the majority of `<a>` elements in the app need to be intercepted by JavaScript to prevent browsers' default action (full page reload). Links in the user menu - which include notifications, reviewables, bookmarks etc. - are no exception to this rule and currently clicks on these items are handled by the global [click-interceptor](1fa21ed415/app/assets/javascripts/discourse/app/lib/intercept-click.js (L20)) which calls the `preventDefault` function on the click event object and uses the `DiscourseURL.routeTo` function to route the user to the page they request.
However, for links in the user menu, there's an extra step which is to let the header know that it should close the user menu after clicking an item in the menu, but the global interceptor doesn't know that because the step is specific to links in the user menu. This can cause a bug on mobile devices where the menu remains open after clicking on a notification which results in the user having to close the menu to see the page that the notification takes them to.
This commit adds a click handler to user menu items that ensures the menu is closed when an item is clicked and navigates the user to wherever the item links to. There's a small downside to this change which is that user menu items now have their own click interceptor instead of relying on the global interceptor, i.e. duplicated logic, but since it's only a couple of lines, I think we can live with it for a while.
I did try to make the click handler of the user menu items only close the menu (call the `closeUserMenu` function), but for some reasons it caused a full page reload to happen when clicking a notification item due to some weird interactions between the header widget and the user menu. I didn't debug this thoroughly because we have plans to change the header implementation from widgets/virtual-dom to Glimmer component, which will likely resolve that weird full page reload issue and we'll be able to make the click handler just close the menu and let the global interceptor prevents the default action and do the routing.
Internal topic: t/71911/118.