This does the same thing for that we did
for in
https://github.com/facebook/react/pull/32612/commits/e3cbaffef05c7b476c07f7495e06788a9503e636.
If a boundary hasn't mutated and didn't change in size, we mark it for
cancellation. Otherwise we add names to it. The different from the
CommitViewTransition path is that the old names are added to the
clones so this is the first time the new names.
Now we also cancel any boundaries that were unchanged. So now the root
no longer animates. We still have to clone them. There are other
optimizations that can avoid cloning but once we've done all the layouts
we can still cancel the running animation and let them just be the
regular content if they didn't change. Just like the regular
fire-and-forget path.
This also fixes the measurement so that we measure clones by adjusting
their position back into the viewport.
This actually surfaces a bug in Safari that was already in #32612. It
turns out that the old names aren't picked up for some reason and so in
Safari they looked more like a cross-fade than what #32612 was supposed
to fix. However, now that bug is even more apparent because they
actually just disappear in Safari. I'm not sure what that bug is but
it's unrelated to this PR so will fix that separately.
DiffTrain build for [3c3696d554](https://github.com/facebook/react/commit/3c3696d5548c8a67f2332fd78332b9366abaf2f9)
This PR separates Activity to it's own element type separate from
Offscreen. The goal is to allow us to add Activity element boundary
semantics during hydration similar to Suspense semantics, without
impacting the Offscreen behavior in suspended children.
DiffTrain build for [1a191701fe](https://github.com/facebook/react/commit/1a191701fe5000098d23328b2ea9d70457fea1f8)
Stacked on #32585 and #32605.
This adds more loops for the phases of "Apply Gesture". It doesn't
implement the interesting bit yet like adding view-transition-names and
measurements. I'll do that in a separate PR to keep reviewing easier.
The three phases of this approach is roughly:
- Clone and apply names to the "old" state.
- Inside startViewTransition: Apply names to the "new" state. Measure
both the "old" and "new" state to know whether to cancel some of them.
Delete the clones which will include all the "old" names.
- After startViewTransition: Restore "new" names back to no
view-transition-name.
Since we don't have any other Effects in these phases we have a bit more
flexibility and we can avoid extra phases that traverse the tree. I've
tried to avoid any additional passes.
An interesting consequence of this approach is that we could measure
both the "old" and "new" state before `startViewTransition`. This would
be more efficient because we wouldn't need to take View Transition
snapshots of parts of the tree that won't actually animate. However,
that would require an extra pass and force layout earlier. It would also
have different semantics from the fire-and-forget View Transitions
because we could optimize better which can be visible. It would also not
account for any late mutations. So I decided to instead let the layout
be computed by painting as usual and then measure both "old" and "new"
inside the startViewTransition instead. Then canceling anything that
doesn't animate to keep it consistent.
Unfortunately, though there's not a lot of code sharing possible in
these phases because the strategy is so different with the cloning and
because the animation is performed in reverse. The "finishedWork" Fiber
represents the "old" state and the "current" Fiber represents the "new"
state.
The most complicated phase is the cloning. I actually ended up having to
make a very different pattern from the other phases and CommitWork in
general. Because we have to clone as we go and also do other things like
apply names and finding pairs, it has more phases. I ended up with an
approach that uses three different loops. The outer one for updated
trees, one for inserted trees that don't need cloning (doesn't include
reappearing offscreen) and one for not updated trees that still need
cloning. Inside each loop it can also be in different phases which I
track with the `visitPhase` enum - this pattern is kind of new.
Additionally, we need to measure the cloned nodes after we've applied
mutations to them and we have to wait until the whole tree is inserted.
We don't have a reference to these DOM elements in the Fiber tree since
that still refers to the original ones. We need to store the cloned
elements somewhere. So I added a temporary field on the
ViewTransitionState to keep track of any clones owned by that
ViewTransition.
When we deep clone an unchanged subtree we don't have DOM element
instances. It wouldn't be quite safe to try to find them from the tree
structure. So we need to avoid the deep clones if we might need DOM
elements. Therefore we keep traversing in the case where we need to find
nested ViewTransition boundaries that are either potentially affected by
layout or a "pair".
For the other two phases the pattern there's a lot of code duplication
since it's slightly different from the commit ones but they at least
follow the same pattern. For the restore phase I was actually able to
reuse most of the code.
I don't love how much code this is.
DiffTrain build for [c4a3b92e09](https://github.com/facebook/react/commit/c4a3b92e098cf1896939758e7419cbdb0e2f0cf4)
This change merges the `react-compiler` rule from
`eslint-plugin-react-compiler` into the `eslint-plugin-react-hooks`
plugin. In order to do the move in a way that keeps commit history with
the moved files, but also no remove them from their origin until a
future cleanup change can be done, I did the `git mv` first, and then
recreated the files that were moved in their original places, as a
separate commit. Unfortunately GH shows the moved files as new instead
of the ones that are truly new. But in the IDE and `git blame`, commit
history is intact with the moved files.
Since this change adds new dependencies, and one of those dependencies
has a higher `engines` declaration for `node` than what the plugin
currently has, this is technically a breaking change and will have to go
out as part of a major release.
### Related Changes
- https://github.com/facebook/react/pull/32458
---------
Co-authored-by: Lauren Tan <poteto@users.noreply.github.com>
DiffTrain build for [5ccfcd17ff](https://github.com/facebook/react/commit/5ccfcd17ffa0adf9e7f5ba7fbf48e6bf6a4eb67e)
*This API is experimental and subject to change or removal.*
This PR is an alternative to
https://github.com/facebook/react/pull/32421 based on feedback:
https://github.com/facebook/react/pull/32421#pullrequestreview-2625382015
. The difference here is that we traverse from the Fragment's fiber at
operation time instead of keeping a set of children on the
`FragmentInstance`. We still need to handle newly added or removed child
nodes to apply event listeners and observers, so we treat those updates
as effects.
**Fragment Refs**
This PR extends React's Fragment component to accept a `ref` prop. The
Fragment's ref will attach to a custom host instance, which will provide
an Element-like API for working with the Fragment's host parent and host
children.
Here I've implemented `addEventListener`, `removeEventListener`, and
`focus` to get started but we'll be iterating on this by adding
additional APIs in future PRs. This sets up the mechanism to attach refs
and perform operations on children. The FragmentInstance is implemented
in `react-dom` here but is planned for Fabric as well.
The API works by targeting the first level of host children and proxying
Element-like APIs to allow developers to manage groups of elements or
elements that cannot be easily accessed such as from a third-party
library or deep in a tree of Functional Component wrappers.
```javascript
import {Fragment, useRef} from 'react';
const fragmentRef = useRef(null);
<Fragment ref={fragmentRef}>
<div id="A" />
<Wrapper>
<div id="B">
<div id="C" />
</div>
</Wrapper>
<div id="D" />
</Fragment>
```
In this case, calling `fragmentRef.current.addEventListener()` would
apply an event listener to `A`, `B`, and `D`. `C` is skipped because it
is nested under the first level of Host Component. If another Host
Component was appended as a sibling to `A`, `B`, or `D`, the event
listener would be applied to that element as well and any other APIs
would also affect the newly added child.
This is an implementation of the basic feature as a starting point for
feedback and further iteration.
DiffTrain build for [6aa8254bb7](https://github.com/facebook/react/commit/6aa8254bb7353fe3096289edc669cf168e9fd190)
This fixes a critical issue with moveBefore. I was told that the
disconnected -> connected case was going to be relaxed and not be an
error but apparently that is not the case.
This means that we can't use this for initial insertions. Only moves.
Unfortunately React's internals doesn't distinguish these cases. This
adds a hack that checks each nodes but this is pretty bad for
performance. We should only call this in one or the other case.
Given that we still need feature detection. Both of which means that
these calls are no longer inlined and this extra code. I wonder if it's
even worth it given that you can't even rely on it working anyway since
not all browsers have it. Kind of don't want to ship this until all
browsers have it.
Even then we'd ideally refactor React to use separate code paths for
initial insertion vs moves. Which leads to some unfortunate code
duplication.
DiffTrain build for [99e1024051](https://github.com/facebook/react/commit/99e1024051f2e6b2d2849b966e2f4354aef2a1d0)
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## Summary
<!--
Explain the **motivation** for making this change. What existing problem
does the pull request solve?
-->
This PR fixes asserts when `passChildrenWhenCloningPersistedNodes` is
enabled for React Native and OffscreenComponent child rendering unhides
host components.
Discussions around possible fixes for the asserts seen in React Native
suggested changing the way we handle hiding/unhiding host components by
updating the fiber state with the hidden host component instead of
submitting a hidden clone Fabric and keeping the original as the current
fiber.
Implementing this fix would require holding onto the original styling of
the hidden host component. The reconciler updates the styling by adding
`display: none` to hide the contents. If the original host component was
already hidden, the renderer would lose that information and remove the
styling when showing the contents again.
To reduce the changes required to make
`passChildrenWhenCloningPersistedNodes` work, this PR falls back to the
original cloning method when OffscreenComponents are part of the
children needed to be added back. This effectively resolve the asserts
triggered by the feature in RN and improves overall performance.
## How did you test this change?
<!--
Demonstrate the code is solid. Example: The exact commands you ran and
their output, screenshots / videos if the pull request changes the user
interface.
How exactly did you verify that your PR solves the issue you wanted to
solve?
If you leave this empty, your PR will very likely be closed.
-->
This fix was tested by enabling `passChildrenWhenCloningPersistedNodes`
in an app built with React Native that had a repro for triggering the
asserts. The asserts do not occur anymore when using the changes in this
PR.
---------
Co-authored-by: Nick <lefever@meta.com>
DiffTrain build for [cc680065c3](https://github.com/facebook/react/commit/cc680065c33739cc4c8cd2e8a67312b0c16a6ccc)
This is really the essence mechanism of the `useSwipeTransition`
feature.
We don't want to immediately switch to the destination state when
starting a gesture. The effects remain mounted on the current state. We
want the current state to be "live". This is important to for example
allow a video to keeping playing while starting a swipe (think
TikTok/Reels) and not stop until you've committed the action. The only
thing that can be live is the "new" state. Therefore we treat the
destination as the "old" state and perform a reverse animation from
there.
Ideally we could apply the old state to the DOM tree, take a snapshot
and then revert it back in the mutation of `startViewTransition`.
Unfortunately, the way `startViewTransition` was designed it always
paints one frame of the "old" state which would lead this to cause a
flicker.
To work around this, we need to create a clone of any View Transition
boundary that might be mutated and then render that offscreen. That way
we can render the "current" state on screen and the "destination" state
offscreen for the screenshots. Being mutated can be either due to React
doing a DOM mutation or if a child boundary resizes that causes the
parent to relayout. We don't have to do this for insertions or deletions
since they only appear on one side.
The worst case scenario is that we have to clone the whole root. That's
what this first PR implements. We clone the container and if it's not
absolutely positioned, we position it on top of the current one. If the
container is `document` or `<html>` we instead clone the `<body>` tag
since it's the only one we can insert a duplicate of. If the container
is deep in the tree we clone just that even though technically we should
probably clone the whole document in that case. We just keep the impact
smaller. Ideally though we'd never hit this case. In fact, if we clone
the document we issue a warning (always for now) since you probably
should optimize this. In the future I intend to add optimizations when
affected View Transition boundaries are absolutely positioned since they
cannot possibly relayout the parent. This would be the ideal way to use
this feature most efficiently but it still works without it.
Since we render the "old" state outside the viewport, we need to then
adjust the animation to put it back into the viewport. This is the
trickiest part to get right while still preserving any customization of
the View Transitions done using CSS. This current approach reapplies all
the animations with adjusted keyframes.
In the case of an "exit" the pseudo-element itself is positioned outside
the viewport but since we can't programmatically update the style of the
pseudo-element itself we instead adjust all the keyframes to put it back
into the viewport. If there is no animation on the group we add one.
In the case of an "update" the pseudo-element is positioned on the new
state which is already inside the viewport. However, the auto-generated
animation of the group has a starting keyframe that starts outside the
viewport. In this case we need to adjust that keyframe.
In the future I might explore a technique that inserts stylesheets
instead of mutating the animations. It might be simpler. But whatever
hacks work to maximize the compatibility is best.
DiffTrain build for [e9252bcdcc](https://github.com/facebook/react/commit/e9252bcdccf7f8f691081e4d48ca47657bc723f9)
We added support for `onScrollEnd` in #26789 but it only works in Chrome
and Firefox. Safari still doesn't support `scrollend` and there's no
indication that they will anytime soon so this polyfills it.
While I don't particularly love our synthetic event system this tries to
stay within the realm of how our other polyfills work. This implements
all `onScrollEnd` events as a plugin.
The basic principle is to first feature detect the `onscrollend` DOM
property to see if there's native support and otherwise just use the
native event.
Then we listen to `scroll` events and set a timeout. If we don't get any
more scroll events before the timeout we fire `onScrollEnd`. Basically
debouncing it. If we're currently pressing down on touch or a mouse then
we wait until it is lifted such as if you're scrolling with a finger or
using the scrollbars on desktop but isn't currently moving.
If we do get any native events even though we're in polyfilling mode, we
use that as an indication to fire the `onScrollEnd` early.
Part of the motivation is that this becomes extra useful pair for
https://github.com/facebook/react/pull/32422. We also probably need
these events to coincide with other gesture related internals so you're
better off using our polyfill so they're synced.
DiffTrain build for [605a880c8c](https://github.com/facebook/react/commit/605a880c8c5191e9f8c52468458709cd17a486c1)
This adds a `ReactFiberApplyGesture` which is basically intended to be a
fork of the phases in `ReactFiberCommitWork` except for the fake commit
that `useSwipeTransition` does. So far none of the phases are actually
implemented yet. This is just the scaffolding around them so I can fill
them in later.
The important bit is that we call `startViewTransition` (via the
`startGestureTransition` Config) when a gesture starts. We add a paused
animation to prevent the transition from committing (even if the
ScrollTimeline goes to 100%). This also locks the documents so that we
can't commit any other Transitions until it completes.
When the gesture completes (scroll end) then we stop the gesture View
Transition. If there's no new work scheduled we do that immediately but
if there was any new work already scheduled, then we assume that this
will potentially commit the new state. So we wait for that to finish.
This lets us lock the animation in its state instead of snapping back
and then applying the real update.
Using this technique we can't actually run a View Transition from the
current state to the actual committed state because it would snap back
to the beginning and then run the View Transition from there. Therefore
any new commit needs to skip View Transitions even if it should've
technically animated to that state. We assume that the new state is the
same as the optimistic state you already swiped to. An alternative to
this technique could be to commit the optimistic state when we cancel
and then apply any new updates o top of that. I might explore that in
the future.
Regardless it's important that the `action` associated with the swipe
schedules some work before we cancel. Otherwise it risks reverting
first. So I had to update this in the fixture.
DiffTrain build for [3607f4838a](https://github.com/facebook/react/commit/3607f4838a8f4a87160da36aa26bb1432d7a5f11)
For the `useId` algorithm we used colon `:` before and after.
https://github.com/facebook/react/pull/23360
This avoids collisions in general by using an unusual characters. It
also avoids collisions when concatenated with some other ID.
Unfortunately, `:` is not a valid character in `view-transition-name`.
This PR swaps the format from:
```
:r123:
```
To the unicode:
```
«r123»
```
Which is valid CSS selectors. This also allows them being used for
`querySelector()` which we didn't really find a legit use for but seems
ok-ish.
That way you can get a view-transition-name that you can manually
reference. E.g. to generate styles:
```js
const id = useId();
return <>
<style>{`
::view-transition-group(${id}) { ... }
::view-transition-old(${id}) { ... }
::view-transition-new(${id}) { ... }
`}</style>
<ViewTransition name={id}>...</ViewTransition>
</>;
```
DiffTrain build for [2e4db3344f](https://github.com/facebook/react/commit/2e4db3344f030fe622152ecc231a7c99a81a9c9d)
## Summary
> [!NOTE]
> This only modifies types, so shouldn't have an impact at runtime.
Some time ago we moved some type definitions from React to React Native
in #26437.
This continues making progress on that so values that are created by
React Native and passed to the React renderer (in this case public
instances) are actually defined in React Native and not in React.
This will allow us to modify the definition of some of these types
without having to make changes in the React repository (in the short
term, we want to refactor PublicInstance from an object to an interface,
and then modify that interface to add all the new DOM methods).
## How did you test this change?
Manually synced `ReactNativeTypes` on top of
https://github.com/facebook/react-native/pull/49602 and verified Flow
passes.
DiffTrain build for [9dd378ff12](https://github.com/facebook/react/commit/9dd378ff1222335ff133bab2d61001fcc84a1c56)
## Summary
The `flow-api-translator` from the `hermes` repo does not support flow
type spreads. It is currently not able to digest the ReactNativeTypes
file as it contains unsupported syntax. The simplest solution is to
change the type of the `TouchedViewDataAtPoint` to equivalent, yet
supported by the Flow tooling. In this case the intersection can be used
as
the `TouchedViewDataAtPoint` and `InspectorData` have no common
property.
## How did you test this change?
Run yarn flow native
DiffTrain build for [e670e72fa0](https://github.com/facebook/react/commit/e670e72fa076449e40172e20d17cc67c1c15419c)
This Hook will be used to drive a View Transition based on a gesture.
```js
const [value, startGesture] = useSwipeTransition(prev, current, next);
```
The `enableSwipeTransition` flag will depend on `enableViewTransition`
flag but we may decide to ship them independently. This PR doesn't do
anything interesting yet. There will be a lot more PRs to build out the
actual functionality. This is just wiring up the plumbing for the new
Hook.
This first PR is mainly concerned with how the whole starts (and stops).
The core API is the `startGesture` function (although there will be
other conveniences added in the future). You can call this to start a
gesture with a source provider. You can call this multiple times in one
event to batch multiple Hooks listening to the same provider. However,
each render can only handle one source provider at a time and so it does
one render per scheduled gesture provider.
This uses a separate `GestureLane` to drive gesture renders by marking
the Hook as having an update on that lane. Then schedule a render. These
renders should be blocking and in the same microtask as the
`startGesture` to ensure it can block the paint. So it's similar to
sync.
It may not be possible to finish it synchronously e.g. if something
suspends. If so, it just tries again later when it can like any other
render. This can also happen because it also may not be possible to
drive more than one gesture at a time like if we're limited to one View
Transition per document. So right now you can only run one gesture at a
time in practice.
These renders never commit. This means that we can't clear the
`GestureLane` the normal way. Instead, we have to clear only the root's
`pendingLanes` if we don't have any new renders scheduled. Then wait
until something else updates the Fiber after all gestures on it have
stopped before it really clears.
DiffTrain build for [a53da6abe1](https://github.com/facebook/react/commit/a53da6abe1593483098df2baf927fe07d80153a5)
## Summary
In React Native, public instances and internal host nodes are not
represented by the same object (ReactNativeElement & shadow nodes vs.
just DOM elements), and the only one that's required for rendering is
the shadow node. Public instances are generally only necessary when
accessed via refs or events, and that usually happens for a small amount
of components in the tree.
This implements an optimization to create the public instance on demand,
instead of eagerly creating it when creating the host node. We expect
this to improve performance by reducing the logic we do per node and the
number of object allocations.
## How did you test this change?
Manually synced the changes to React Native and run Fantom tests and
benchmarks, with the flag enabled and disabled. All tests pass in both
cases, and benchmarks show a slight but consistent performance
improvement.
DiffTrain build for [f83903bfcc](https://github.com/facebook/react/commit/f83903bfcc5a61811bd1b69b14f0ebbac4754462)
While modern DOM implementations all support getRootNode if you are
running React in a runtime which does not the fallback logic which uses
`.ownerDocument` works everywhere except when the container is a
Document itself. This change corrects this by returning the container
intsance if it is a Document type.
DiffTrain build for [b48e739998](https://github.com/facebook/react/commit/b48e739998432fc9672a42d0d04515980b8cae82)
3 years ago we partially disabled comment nodes as valid containers.
Some unflagged support was left in due to legacy APIs like
`unmountComponentAtNode` and `unstable_renderSubtreeIntoContainer` but
these were since removed in React 19. This update flags the remaining
uses of comments as containers.
DiffTrain build for [0605cd9f38](https://github.com/facebook/react/commit/0605cd9f38f8b9d0ca6f8bd9dd3409db8d6c5c81)
follow up to https://github.com/facebook/react/pull/32163
This continues the work of making Suspense workable anywhere in a
react-dom tree. See the prior PRs for how we handle server rendering and
client rendering. In this change we update the hydration implementation
to be able to locate expected nodes. In particular this means hydration
understands now that the default hydration context is the document body
when the container is above the body.
One case that is unique to hydration is clearing Suspense boundaries.
When hydration fails or when the server instructs the client to recover
an errored boundary it's possible that the html, head, and body tags in
the initial document were written from a fallback or a different primary
content on the server and need to be replaced by the client render.
However these tags (and in the case of head, their content) won't be
inside the comment nodes that identify the bounds of the Suspense
boundary. And when client rendering you may not even render the same
singletons that were server rendered. So when server rendering a
boudnary which contributes to the preamble (the html, head, and body tag
openings plus the head contents) we emit a special marker comment just
before closing the boundary out. This marker encodes which parts of the
preamble this boundary owned. If we need to clear the suspense boundary
on the client we read this marker and use it to reset the appropriate
singleton state.
DiffTrain build for [8bda71558c](https://github.com/facebook/react/commit/8bda71558c8b6f9f19af33271f1bfd0251a1c071)
## Summary
When lookup `Parent`, `HostRoot` and `HostPortal` should be merged,
because when creating a `Portal`, it will also include
`containerInfo`(So we can directly use this `containerInfo` to delete
the real DOM nodes.), so there is no need to handle them separately.
## How did you test this change?
No behavior changes, all existing tests pass.
DiffTrain build for [19ca800caa](https://github.com/facebook/react/commit/19ca800caa01eec2f5e65e547c67b11592bec8b0)