## Root-cause
`https://github.com/videojs/video.js/pull/7098`
videojs was recently upgraded.
## Change
Override videojs default theme of hiding the time control in smaller layouts.
## Issue
#6332 <Thumbnail lazy-loader is too slow || Use browser-level lazy-loading>
## Change
Switch from "threshold-based check" to "viewport distance comparison" using the `rootMargin` parameter. The root is the viewport.
This change makes it closer to the native `loading="lazy"` behavior, where it starts to load when approaching the viewport. Chrome I believe uses 3000px distance -- I think 500px is a good compromise for now. Can adjust further.
## Future
- We are currently creating N instances of IntersectionObserver.
- https://developers.google.com/web/updates/2016/04/intersectionobserver
- "If you need to observe multiple elements, it is both possible and advised to observe multiple elements using the same IntersectionObserver instance by calling observe() multiple times."
This would probably need a refactor to make ClaimList (or something higher) own the IntersectionObserver.
It was waiting too near the viewport to load on certain zoom levels. This will maintain the same physical distance for the "approaching viewport" buffer regardless of zoom levels.
## Changes
- Change to canonical_url (with ':').
- The old format of 'claimName/claimId' needs to be supported still, since we shipped with it.
## Notes
- It would be nice to use regex instead of 2 separate paths, but I couldn't figure out how to make the koa variables work.
We currently handle major errors through ErrorBoundary. If the error is network related, ErrorBoundary ends up blank if it's components are lazy-loaded.
#codesplit
It won't work with the hardcoded value.
Still waiting for commentron (error code + data) enhancement. It's pretty weird having to parse the number, then add it back in.
## Issue
Sub item in <6119 Creator Settings: beyond "Muted Words">
## Changes
- Removed the existing 5s min gap on livestreams.
- Enabled the 'slow mode min gap' in Creator Settings
This change now affects both comments in claims and livestream comments.
## Issue
The loading circle wasn't showing up, causing confusion.
Splitting CSS doesn't seem trivial as there seems to be a huge dependency on the load order. Pretty much similar to what this person is facing https://lihautan.com/css-code-splitting/#the-problem
## Change
This reverts videojs-specific changes from 4d638bcf.
## Issue
When seeking on a video, RecommendedContent gets re-rendered, which causes the 20 ClaimPreviews to be re-rendered, several times. ClaimPreview has lots of children, plus it's constantly checking against the blacklist, among other things.
## Fix
The culprit seems to be the `recommendedContent` array -- the address may be different, but the contents are the same.
Do a deep compare instead.
- [x] (6332) The IntersectionObserver method of lazy-loading loads cached images visibly late on slower devices. Previously, it was also showing the "broken image" icon briefly, which we mended by placing a dummy transparent image as the initial src.
- Reverted that ugly transparent image fix.
- Use the browser's built-in `loading="lazy"` instead. Sorry, Safari.
- [x] Size-optimization did not take "device pixel ratio" into account.
- When resizing an image through the CDN, we can't just take the dimensions of the tag in pixels directly -- we need to take zooming into account, otherwise the image ends up blurry.
- Previously, we quickly disabled optimization for the channel avatar in the Channel Page because of this. Now that we know the root-cause, the change was reverted and we now go through the CDN with appropriate sizes. This also improves our Web Vital scores.
- [x] Size-optimization wasn't really implemented for all ChannelThumbnail instances.
- The CDN-optimized size was hardcoded to the largest instance, so small images like sidebar thumbnails are still loading images that are unnecessarily larger.
- There's a little-bit of hardcoding of values from CSS here, but I think it's a ok compromise (not something we change often). It also doesn't need to be exact -- the "device pixel ratio" calculate will ensure it's slightly larger than what we need.
- [x] Set `width` and `height` of `<img>` to improve CLS.
- Addresses Ligthhouse complaints, although technically the shifting was addressed at the `ClaimPreviewTile` level (sub-container dimensions are well defined).
- Notes: the values don't need to be the final CSS-adjusted sizes. It just needs to be in the right aspect ratio to help the browser pre-allocate space to avoid shifts.
- [x] Add option to disable lazy-load Channel Thumbnails
- The guidelines mentioned that items that are already in the viewport should not enable `loading="lazy"`.
- We have a few areas where it doesn't make sense to lazy-load (e.g. thumbnail in Header, channel selector dropdown, publish preview, etc.).
## Issue
The scroll listener never unregisters, and is always registering itself on every scroll. I believe it was done that way to also handle the case of "element is already in viewport when mounted".
## Change
Tried to separate both "element is already in viewport when mounted" and "element scrolled into viewport" into different effects.
The timeout value used is a bit arbitrary, but is needed because the initial size is (0, 0), and to debounce any layout shifts. Reasoning: If an element is explicitly placed under this wrapper, the additional delay is acceptable since it's meant to be lazy-loaded anyway.
