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https://github.com/facebook/react.git
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Jack Pope
6aa8254bb7
*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.
52 lines
2.2 KiB
JavaScript
52 lines
2.2 KiB
JavaScript
/**
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow strict
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*/
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// In www, these flags are controlled by GKs. Because most GKs have some
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// population running in either mode, we should run our tests that way, too,
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//
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// Use __VARIANT__ to simulate a GK. The tests will be run twice: once
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// with the __VARIANT__ set to `true`, and once set to `false`.
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export const alwaysThrottleRetries = true;
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export const disableDefaultPropsExceptForClasses = __VARIANT__;
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export const disableLegacyContextForFunctionComponents = __VARIANT__;
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export const disableSchedulerTimeoutInWorkLoop = __VARIANT__;
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export const enableDO_NOT_USE_disableStrictPassiveEffect = __VARIANT__;
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export const enableHiddenSubtreeInsertionEffectCleanup = __VARIANT__;
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export const enableNoCloningMemoCache = __VARIANT__;
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export const enableObjectFiber = __VARIANT__;
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export const enableRenderableContext = __VARIANT__;
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export const enableRetryLaneExpiration = __VARIANT__;
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export const enableTransitionTracing = __VARIANT__;
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export const favorSafetyOverHydrationPerf = __VARIANT__;
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export const renameElementSymbol = __VARIANT__;
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export const retryLaneExpirationMs = 5000;
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export const syncLaneExpirationMs = 250;
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export const transitionLaneExpirationMs = 5000;
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export const enableSchedulingProfiler = __VARIANT__;
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export const enableInfiniteRenderLoopDetection = __VARIANT__;
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export const enableSiblingPrerendering = __VARIANT__;
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export const enableUseEffectCRUDOverload = __VARIANT__;
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export const enableFastAddPropertiesInDiffing = __VARIANT__;
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export const enableLazyPublicInstanceInFabric = false;
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export const enableViewTransition = __VARIANT__;
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export const enableComponentPerformanceTrack = __VARIANT__;
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export const enableScrollEndPolyfill = __VARIANT__;
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export const enableFragmentRefs = __VARIANT__;
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// TODO: These flags are hard-coded to the default values used in open source.
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// Update the tests so that they pass in either mode, then set these
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// to __VARIANT__.
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export const enableTrustedTypesIntegration = false;
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// You probably *don't* want to add more hardcoded ones.
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// Instead, try to add them above with the __VARIANT__ value.
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