Uh oh!
There was an error while loading. Please reload this page.
Add (Client) Functions as Form Actions - #26674
Merged
Merged
Conversation
sebmarkbage
commented
Apr 19, 2023
Uh oh!
There was an error while loading. Please reload this page.
acdlite
approved these changes
Apr 19, 2023
acdlite
left a comment
Collaborator
There was a problem hiding this comment.
Stamping the parts I’m familiar with, will let @sophiebits handle the rest
sebmarkbage
commented
Apr 19, 2023
| } | ||
| case 'action': | ||
| case 'formAction': { | ||
| // TODO: Consider moving these special cases to the form, input and button tags. |
ContributorAuthor
There was a problem hiding this comment.
I decided to leave these here for now and not special case per tag. To keep the code smaller. Ideally these should follow the pattern of input, select and textarea instead.
That way we could more easily clear out props like target, method and encType when they're not relevant or set them to what they're supposed to be. That's what Fizz does. That probably also lead to hydration warnings but they also warn just in general.
sebmarkbage
commented
Apr 19, 2023
| "consider using form.requestSubmit() instead. If you're trying to use " + | ||
| 'event.stopPropagation() in a submit event handler, consider also calling ' + | ||
| 'event.preventDefault().' + | ||
| "')", |
ContributorAuthor
There was a problem hiding this comment.
This doesn't get minified but it doesn't have access to the shared helper anyway so we can't really do that the same way anyway. We could consider a shorter message which is what I did for SSR.
sebmarkbageforce-pushed
the
formactions
branch
4 times, most recently
from
April 19, 2023 18:57
a14141b to
ffee4ceCompareButtons with actions have to be wrapped in form elements. They can't be standalone unfortunately because it's the act of submitting the form that triggers the action. This also ensures that the progressive enhancement can work properly too.
sophiebits
approved these changes
Apr 19, 2023
Uh oh!
There was an error while loading. Please reload this page.
Uh oh!
There was an error while loading. Please reload this page.
Uh oh!
There was an error while loading. Please reload this page.
Uh oh!
There was an error while loading. Please reload this page.
| didWarnFormActionTarget = true; | ||
| console.error( | ||
| 'Cannot specify a target for a form that specifies a function as the action. ' + | ||
| 'The function will always be executed in the same scope.', |
Collaborator
There was a problem hiding this comment.
maybe "same window" would be clearer?
Uh oh!
There was an error while loading. Please reload this page.
| } | ||
| } | ||
| // Since this will likely be repeated a lot in the HTML, we use a more concise message |
Collaborator
There was a problem hiding this comment.
could make a $RF helper for this I guess?
ContributorAuthor
There was a problem hiding this comment.
oh you mean to call a global. Yea, but this might also be opened in new tabs etc. which is annoying.
ContributorAuthor
There was a problem hiding this comment.
I suppose it doesn't matter much if the error message isn't great for that case.
Uh oh!
There was an error while loading. Please reload this page.
| innerHTML = propValue; | ||
| break; | ||
| case 'action': | ||
| formAction = propValue; |
Collaborator
There was a problem hiding this comment.
nit: confusing to call these variables form_
| continue; | ||
| } else if (hasFormActionURL) { | ||
| extraAttributes.delete(propKey.toLowerCase()); | ||
| warnForPropDifference(propKey, 'function', value); |
Collaborator
There was a problem hiding this comment.
nit: quotes in the warning :(
ContributorAuthor
There was a problem hiding this comment.
The reason I did it this way for now, instead of a custom warning, is that we probably want to join all the differences together in a larger diff. So this will have to change as part of that. We could pass a fake function or something to indicate how this should be rendered I guess.
This can still possibly have a null formAction in which case React still handles it.
sebmarkbage
commented
Apr 19, 2023
| const root = ReactDOMClient.createRoot(container); | ||
| await act(async () => { | ||
| root.render( | ||
| <form |
ContributorAuthor
There was a problem hiding this comment.
If the form is not a React element is already handled by the event system itself.
kassens pushed a commit
that referenced
this pull request
Apr 21, 2023
This lets you pass a function to `<form action={...}>` or `<button
formAction={...}>` or `<input type="submit formAction={...}>`. This will
behave basically like a `javascript:` URL except not quite implemented
that way. This is a convenience for the `onSubmit={e => {
e.preventDefault(); const fromData = new FormData(e.target); ... }`
pattern.
You can still implement a custom `onSubmit` handler and if it calls
`preventDefault`, it won't invoke the action, just like it would if you
used a full page form navigation or javascript urls. It behaves just
like a navigation and we might implement it with the Navigation API in
the future.
Currently this is just a synchronous function but in a follow up this
will accept async functions, handle pending states and handle errors.
This is implemented by setting `javascript:` URLs, but these only exist
to trigger an error message if something goes wrong instead of
navigating away. Like if you called `stopPropagation` to prevent React
from handling it or if you called `form.submit()` instead of
`form.requestSubmit()` which by-passes the `submit` event. If CSP is
used to ban `javascript:` urls, those will trigger errors when these
URLs are invoked which would be a different error message but it's still
there to notify the user that something went wrong in the plumbing.
Next up is improving the SSR state with action replaying and progressive
enhancement.jenseng
reviewed
Apr 26, 2023
| // late. The easiest way to do this is to switch the form field to hidden, | ||
| // which is always included, and then back again. This does means that this | ||
| // is observable from the formdata event though. | ||
| // TODO: This tricky doesn't work on button elements. Consider inserting |
Contributor
There was a problem hiding this comment.
You might consider leveraging https://www.npmjs.com/package/formdata-submitter-polyfill or borrowing its approach ... in addition to handling <button>, it also does the right thing with <input type="image">
Contributor
There was a problem hiding this comment.
Or alternatively don't attempt to emulate it at all, but instead just pass the submitter to the constructor so that new browsers do the right thing for all submitter types, and if developers want to support old browsers they can polyfill it.
| // is observable from the formdata event though. | ||
| // TODO: This tricky doesn't work on button elements. Consider inserting | ||
| // a fake node instead for that case. | ||
| // TODO: FormData takes a second argument that it's the submitter but this |
Contributor
There was a problem hiding this comment.
This is available in the latest versions of all major browsers now: https://developer.mozilla.org/en-US/docs/Web/API/FormData/FormData#browser_compatibility ... should be available in jest+jsdom very soon too 🤞
ContributorAuthor
There was a problem hiding this comment.
Unfortunately not all browsers are truly evergreen. We support a lot of old Samsung TVs and many iOS users don't upgrade for years. So we can't use it yet. Not worth the added code to do the image one.
ContributorAuthor
There was a problem hiding this comment.
Note that we do it a little differently now. https://github.com/facebook/react/blob/main/packages/react-dom-bindings/src/events/plugins/FormActionEventPlugin.js#L92-L97
Contributor
There was a problem hiding this comment.
Edit GitHub didn't show me your second message when I wrote this reply, web apps are hard 😆
That makes sense, thanks for the added context 👍
Though if you're supporting old browsers, many don't support SubmitEvent so you won't have a submitter here in the first place. And for modern browsers, a typical edit new way looks more robust 👍submitter won't work with the type="hidden" hack (i.e. IME <button> is much more prevalent than <input type=submit>).
Since browsers that support SubmitEvent are fairly likely to be evergreen, would it be better to just remove the hack altogether and pass the submitter (if any) to FormData? Then you'd get more correct 1 behavior with less code.
Footnotes
In addition to not supporting image button submitters, the latest approach also doesn't support form-associated submitters that aren't descendants of the form (e.g.
<form id=foo>...</form><button form=foo name=outside />) ↩
ContributorAuthor
There was a problem hiding this comment.
We don't support very old, like we don't support IE anymore, however we support somewhat old browser like TVs and iOS versions a year or so old. Point taken that maybe it's not even enough to rely on the submitter property on the event.
I'd expect us to only keep this hack around for maybe 6 months or so until we switch to the native version given this awkward transition stage.
EdisonVan pushed a commit
to EdisonVan/react
that referenced
this pull request
Apr 15, 2024
This lets you pass a function to `<form action={...}>` or `<button
formAction={...}>` or `<input type="submit formAction={...}>`. This will
behave basically like a `javascript:` URL except not quite implemented
that way. This is a convenience for the `onSubmit={e => {
e.preventDefault(); const fromData = new FormData(e.target); ... }`
pattern.
You can still implement a custom `onSubmit` handler and if it calls
`preventDefault`, it won't invoke the action, just like it would if you
used a full page form navigation or javascript urls. It behaves just
like a navigation and we might implement it with the Navigation API in
the future.
Currently this is just a synchronous function but in a follow up this
will accept async functions, handle pending states and handle errors.
This is implemented by setting `javascript:` URLs, but these only exist
to trigger an error message if something goes wrong instead of
navigating away. Like if you called `stopPropagation` to prevent React
from handling it or if you called `form.submit()` instead of
`form.requestSubmit()` which by-passes the `submit` event. If CSP is
used to ban `javascript:` urls, those will trigger errors when these
URLs are invoked which would be a different error message but it's still
there to notify the user that something went wrong in the plumbing.
Next up is improving the SSR state with action replaying and progressive
enhancement.bigfootjon pushed a commit
that referenced
this pull request
Apr 18, 2024
This lets you pass a function to `<form action={...}>` or `<button
formAction={...}>` or `<input type="submit formAction={...}>`. This will
behave basically like a `javascript:` URL except not quite implemented
that way. This is a convenience for the `onSubmit={e => {
e.preventDefault(); const fromData = new FormData(e.target); ... }`
pattern.
You can still implement a custom `onSubmit` handler and if it calls
`preventDefault`, it won't invoke the action, just like it would if you
used a full page form navigation or javascript urls. It behaves just
like a navigation and we might implement it with the Navigation API in
the future.
Currently this is just a synchronous function but in a follow up this
will accept async functions, handle pending states and handle errors.
This is implemented by setting `javascript:` URLs, but these only exist
to trigger an error message if something goes wrong instead of
navigating away. Like if you called `stopPropagation` to prevent React
from handling it or if you called `form.submit()` instead of
`form.requestSubmit()` which by-passes the `submit` event. If CSP is
used to ban `javascript:` urls, those will trigger errors when these
URLs are invoked which would be a different error message but it's still
there to notify the user that something went wrong in the plumbing.
Next up is improving the SSR state with action replaying and progressive
enhancement.
DiffTrain build for commit c826dc5.ahacop added a commit
to changebot-ai/widgets
that referenced
this pull request
Aug 24, 2026
[cb skip]
Packages updated:
- react 18.3.1 -> 19.2.8 (dev)
- react-dom 18.3.1 -> 19.2.8 (dev)
- @types/react 18.3.26 -> 19.2.18 (dev)
- @types/react-dom 18.3.7 -> 19.2.4 (dev)
These are dev dependencies of @changebot/widgets-react, used to
compile the generated wrappers. The peer range stays >=16.8.0.
react-demo.html keeps loading React 18 from unpkg because React 19
publishes no UMD build, and that page uses the custom elements
directly rather than the wrapper.
== 19.2.7 (June 1, 2026)
== React Server Components
- Fixed missing `FormData` entries in Server Actions which regressed in 19.2.6 (@unstubbable [#36566](https://github.com/facebook/react/pull/36566))
== 19.2.6 (May 6, 2026)
== React Server Components
- Type hardening and performance improvements (@eps1lon, @unstubbable [#36425](https://github.com/facebook/react/pull/36425))
== 19.2.5 (March 18, 2026)
== React Server Components
- Add more cycle protections (@eps1lon, @unstubbable [#36236](https://github.com/facebook/react/pull/36236))
== 19.2.4 (Jan 26, 2026)
== React Server Components
- Add more DoS mitigations to Server Actions, and harden Server Components (@gnoff, @lubieowoce, @sebmarkbage, @unstubbable [#35632](https://github.com/facebook/react/pull/35632))
== 19.2.3 (Dec 11, 2025)
== React Server Components
- Add extra loop protection to React Server Functions (@sebmarkbage [#35351](https://github.com/facebook/react/pull/35351))
== 19.2.2 (Dec 11, 2025)
== React Server Components
- Move `react-server-dom-webpack/*.unbundled` to private `react-server-dom-unbundled` (@eps1lon [#35290](https://github.com/facebook/react/pull/35290))
- Patch Promise cycles and toString on Server Functions (@sebmarkbage, @unstubbable [#35289](https://github.com/facebook/react/pull/35289), [#35345](https://github.com/facebook/react/pull/35345))
== 19.2.1 (Dec 3, 2025)
== React Server Components
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
== 19.2.0 (October 1st, 2025)
Below is a list of all new features, APIs, and bug fixes.
Read the [React 19.2 release post](https://react.dev/blog/2025/10/01/react-19-2) for more information.
== New React Features
- [`<Activity>`](https://react.dev/reference/react/Activity): A new API to hide and restore the UI and internal state of its children.
- [`useEffectEvent`](https://react.dev/reference/react/useEffectEvent) is a React Hook that lets you extract non-reactive logic into an [Effect Event](https://react.dev/learn/separating-events-from-effects#declaring-an-effect-event).
- [`cacheSignal`](https://react.dev/reference/react/cacheSignal) (for RSCs) lets your know when the `cache()` lifetime is over.
- [React Performance tracks](https://react.dev/reference/dev-tools/react-performance-tracks) appear on the Performance panel’s timeline in your browser developer tools
== New React DOM Features
- Added resume APIs for partial pre-rendering with Web Streams:
- [`resume`](https://react.dev/reference/react-dom/server/resume): to resume a prerender to a stream.
- [`resumeAndPrerender`](https://react.dev/reference/react-dom/static/resumeAndPrerender): to resume a prerender to HTML.
- Added resume APIs for partial pre-rendering with Node Streams:
- [`resumeToPipeableStream`](https://react.dev/reference/react-dom/server/resumeToPipeableStream): to resume a prerender to a stream.
- [`resumeAndPrerenderToNodeStream`](https://react.dev/reference/react-dom/static/resumeAndPrerenderToNodeStream): to resume a prerender to HTML.
- Updated [`prerender`](https://react.dev/reference/react-dom/static/prerender) APIs to return a `postponed` state that can be passed to the `resume` APIs.
== Notable changes
- React DOM now batches suspense boundary reveals, matching the behavior of client side rendering. This change is especially noticeable when animating the reveal of Suspense boundaries e.g. with the upcoming `<ViewTransition>` Component. React will batch as much reveals as possible before the first paint while trying to hit popular first-contentful paint metrics.
- Add Node Web Streams (`prerender`, `renderToReadableStream`) to server-side-rendering APIs for Node.js
- Use underscore instead of `:` IDs generated by useId
== All Changes
== React
- `<Activity />` was developed over many years, starting before `ClassComponent.setState` (@acdlite @sebmarkbage and many others)
- Stringify context as "SomeContext" instead of "SomeContext.Provider" (@kassens [#33507](https://github.com/facebook/react/pull/33507))
- Include stack of cause of React instrumentation errors with `%o` placeholder (@eps1lon [#34198](https://github.com/facebook/react/pull/34198))
- Fix infinite `useDeferredValue` loop in popstate event (@acdlite [#32821](https://github.com/facebook/react/pull/32821))
- Fix a bug when an initial value was passed to `useDeferredValue` (@acdlite [#34376](https://github.com/facebook/react/pull/34376))
- Fix a crash when submitting forms with Client Actions (@sebmarkbage [#33055](https://github.com/facebook/react/pull/33055))
- Hide/unhide the content of dehydrated suspense boundaries if they resuspend (@sebmarkbage [#32900](https://github.com/facebook/react/pull/32900))
- Avoid stack overflow on wide trees during Hot Reload (@sophiebits [#34145](https://github.com/facebook/react/pull/34145))
- Improve Owner and Component stacks in various places (@sebmarkbage, @eps1lon: [#33629](https://github.com/facebook/react/pull/33629), [#33724](https://github.com/facebook/react/pull/33724), [#32735](https://github.com/facebook/react/pull/32735), [#33723](https://github.com/facebook/react/pull/33723))
- Add `cacheSignal` (@sebmarkbage [#33557](https://github.com/facebook/react/pull/33557))
== React DOM
- Block on Suspensey Fonts during reveal of server-side-rendered content (@sebmarkbage [#33342](https://github.com/facebook/react/pull/33342))
- Use underscore instead of `:` for IDs generated by `useId` (@sebmarkbage, @eps1lon: [#32001](https://github.com/facebook/react/pull/32001), [https://github.com/facebook/react/pull/33342](https://github.com/facebook/react/pull/33342)[#33099](https://github.com/facebook/react/pull/33099), [#33422](https://github.com/facebook/react/pull/33422))
- Stop warning when ARIA 1.3 attributes are used (@Abdul-Omira [#34264](https://github.com/facebook/react/pull/34264))
- Allow `nonce` to be used on hoistable styles (@Andarist [#32461](https://github.com/facebook/react/pull/32461))
- Warn for using a React owned node as a Container if it also has text content (@sebmarkbage [#32774](https://github.com/facebook/react/pull/32774))
- s/HTML/text for for error messages if text hydration mismatches (@rickhanlonii [#32763](https://github.com/facebook/react/pull/32763))
- Fix a bug with `React.use` inside `React.lazy`\-ed Component (@hi-ogawa [#33941](https://github.com/facebook/react/pull/33941))
- Enable the `progressiveChunkSize` option for server-side-rendering APIs (@sebmarkbage [#33027](https://github.com/facebook/react/pull/33027))
- Fix a bug with deeply nested Suspense inside Suspense fallback when server-side-rendering (@gnoff [#33467](https://github.com/facebook/react/pull/33467))
- Avoid hanging when suspending after aborting while rendering (@gnoff [#34192](https://github.com/facebook/react/pull/34192))
- Add Node Web Streams to server-side-rendering APIs for Node.js (@sebmarkbage [#33475](https://github.com/facebook/react/pull/33475))
== React Server Components
- Preload `<img>` and `<link>` using hints before they're rendered (@sebmarkbage [#34604](https://github.com/facebook/react/pull/34604))
- Log error if production elements are rendered during development (@eps1lon [#34189](https://github.com/facebook/react/pull/34189))
- Fix a bug when returning a Temporary reference (e.g. a Client Reference) from Server Functions (@sebmarkbage [#34084](https://github.com/facebook/react/pull/34084), @denk0403 [#33761](https://github.com/facebook/react/pull/33761))
- Pass line/column to `filterStackFrame` (@eps1lon [#33707](https://github.com/facebook/react/pull/33707))
- Support Async Modules in Turbopack Server References (@lubieowoce [#34531](https://github.com/facebook/react/pull/34531))
- Add support for .mjs file extension in Webpack (@jennyscript [#33028](https://github.com/facebook/react/pull/33028))
- Fix a wrong missing key warning (@unstubbable [#34350](https://github.com/facebook/react/pull/34350))
- Make console log resolve in predictable order (@sebmarkbage [#33665](https://github.com/facebook/react/pull/33665))
== React Reconciler
- [createContainer](https://github.com/facebook/react/blob/v19.2.0/packages/react-reconciler/src/ReactFiberReconciler.js#L255-L261) and [createHydrationContainer](https://github.com/facebook/react/blob/v19.2.0/packages/react-reconciler/src/ReactFiberReconciler.js#L305-L312) had their parameter order adjusted after `on*` handlers to account for upcoming experimental APIs
== 19.1.8 (June 1, 2026)
== React Server Components
- Fixed missing `FormData` entries in Server Actions which regressed in 19.1.7 (@unstubbable [#36567](https://github.com/facebook/react/pull/36567))
== 19.1.7 (May 6, 2026)
== React Server Components
- Type hardening and performance improvements (@eps1lon, @unstubbable [#36425](https://github.com/facebook/react/pull/36425))
== 19.1.6 (March 18, 2026)
== React Server Components
- Add more cycle protections (@eps1lon, @unstubbable [#36236](https://github.com/facebook/react/pull/36236))
== 19.1.5 (Jan 26, 2026)
== React Server Components
- Add more DoS mitigations to Server Actions, and harden Server Components (@gnoff, @lubieowoce, @sebmarkbage, @unstubbable [#35632](https://github.com/facebook/react/pull/35632))
== 19.1.4 (Dec 11, 2025)
== React Server Components
- Add extra loop protection to React Server Functions (@sebmarkbage [#35351](https://github.com/facebook/react/pull/35351))
== 19.1.3 (Dec 11, 2025)
== React Server Components
- Move `react-server-dom-webpack/*.unbundled` to private `react-server-dom-unbundled` (@eps1lon [#35290](https://github.com/facebook/react/pull/35290))
- Patch Promise cycles and toString on Server Functions (@sebmarkbage, @unstubbable [#35289](https://github.com/facebook/react/pull/35289), [#35345](https://github.com/facebook/react/pull/35345))
== 19.1.2 (Dec 3, 2025)
== React Server Components
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
== 19.1.1 (July 28, 2025)
== React
* Fixed Owner Stacks to work with ES2015 function.name semantics ([#33680](https://github.com/facebook/react/pull/33680) by @hoxyq)
== 19.1.0 (March 28, 2025)
== Owner Stack
An Owner Stack is a string representing the components that are directly responsible for rendering a particular component. You can log Owner Stacks when debugging or use Owner Stacks to enhance error overlays or other development tools. Owner Stacks are only available in development builds. Component Stacks in production are unchanged.
* An Owner Stack is a development-only stack trace that helps identify which components are responsible for rendering a particular component. An Owner Stack is distinct from a Component Stacks, which shows the hierarchy of components leading to an error.
* The [captureOwnerStack API](https://react.dev/reference/react/captureOwnerStack) is only available in development mode and returns a Owner Stack, if available. The API can be used to enhance error overlays or log component relationships when debugging. [#29923](https://github.com/facebook/react/pull/29923), [#32353](https://github.com/facebook/react/pull/32353), [#30306](https://github.com/facebook/react/pull/30306),
[#32538](https://github.com/facebook/react/pull/32538), [#32529](https://github.com/facebook/react/pull/32529), [#32538](https://github.com/facebook/react/pull/32538)
== React
* Enhanced support for Suspense boundaries to be used anywhere, including the client, server, and during hydration. [#32069](https://github.com/facebook/react/pull/32069), [#32163](https://github.com/facebook/react/pull/32163), [#32224](https://github.com/facebook/react/pull/32224), [#32252](https://github.com/facebook/react/pull/32252)
* Reduced unnecessary client rendering through improved hydration scheduling [#31751](https://github.com/facebook/react/pull/31751)
* Increased priority of client rendered Suspense boundaries [#31776](https://github.com/facebook/react/pull/31776)
* Fixed frozen fallback states by rendering unfinished Suspense boundaries on the client. [#31620](https://github.com/facebook/react/pull/31620)
* Reduced garbage collection pressure by improving Suspense boundary retries. [#31667](https://github.com/facebook/react/pull/31667)
* Fixed erroneous “Waiting for Paint” log when the passive effect phase was not delayed [#31526](https://github.com/facebook/react/pull/31526)
* Fixed a regression causing key warnings for flattened positional children in development mode. [#32117](https://github.com/facebook/react/pull/32117)
* Updated `useId` to use valid CSS selectors, changing format from `:r123:` to `«r123»`. [#32001](https://github.com/facebook/react/pull/32001)
* Added a dev-only warning for null/undefined created in useEffect, useInsertionEffect, and useLayoutEffect. [#32355](https://github.com/facebook/react/pull/32355)
* Fixed a bug where dev-only methods were exported in production builds. React.act is no longer available in production builds. [#32200](https://github.com/facebook/react/pull/32200)
* Improved consistency across prod and dev to improve compatibility with Google Closure Compiler and bindings [#31808](https://github.com/facebook/react/pull/31808)
* Improve passive effect scheduling for consistent task yielding. [#31785](https://github.com/facebook/react/pull/31785)
* Fixed asserts in React Native when passChildrenWhenCloningPersistedNodes is enabled for OffscreenComponent rendering. [#32528](https://github.com/facebook/react/pull/32528)
* Fixed component name resolution for Portal [#32640](https://github.com/facebook/react/pull/32640)
* Added support for beforetoggle and toggle events on the dialog element. [#32479](https://github.com/facebook/react/pull/32479)
== React DOM
* Fixed double warning when the `href` attribute is an empty string [#31783](https://github.com/facebook/react/pull/31783)
* Fixed an edge case where `getHoistableRoot()` didn’t work properly when the container was a Document [#32321](https://github.com/facebook/react/pull/32321)
* Removed support for using HTML comments (e.g. `<!-- -->`) as a DOM container. [#32250](https://github.com/facebook/react/pull/32250)
* Added support for `<script>` and `<template>` tags to be nested within `<select>` tags. [#31837](https://github.com/facebook/react/pull/31837)
* Fixed responsive images to be preloaded as HTML instead of headers [#32445](https://github.com/facebook/react/pull/32445)
== use-sync-external-store
* Added `exports` field to `package.json` for `use-sync-external-store` to support various entrypoints. [#25231](https://github.com/facebook/react/pull/25231)
== React Server Components
* Added `unstable_prerender`, a new experimental API for prerendering React Server Components on the server [#31724](https://github.com/facebook/react/pull/31724)
* Fixed an issue where streams would hang when receiving new chunks after a global error [#31840](https://github.com/facebook/react/pull/31840), [#31851](https://github.com/facebook/react/pull/31851)
* Fixed an issue where pending chunks were counted twice. [#31833](https://github.com/facebook/react/pull/31833)
* Added support for streaming in edge environments [#31852](https://github.com/facebook/react/pull/31852)
* Added support for sending custom error names from a server so that they are available in the client for console replaying. [#32116](https://github.com/facebook/react/pull/32116)
* Updated the server component wire format to remove IDs for hints and console.log because they have no return value [#31671](https://github.com/facebook/react/pull/31671)
* Exposed `registerServerReference` in client builds to handle server references in different environments. [#32534](https://github.com/facebook/react/pull/32534)
* Added react-server-dom-parcel package which integrates Server Components with the [Parcel bundler](https://parceljs.org/) [#31725](https://github.com/facebook/react/pull/31725), [#32132](https://github.com/facebook/react/pull/32132), [#31799](https://github.com/facebook/react/pull/31799), [#32294](https://github.com/facebook/react/pull/32294), [#31741](https://github.com/facebook/react/pull/31741)
== 19.0.7 (June 1, 2026)
== React Server Components
- Fixed missing `FormData` entries in Server Actions which regressed in 19.0.6 (@unstubbable [#36568](https://github.com/facebook/react/pull/36568))
== 19.0.6 (May 6, 2026)
== React Server Components
- Type hardening and performance improvements (@eps1lon, @unstubbable [#36425](https://github.com/facebook/react/pull/36425))
== 19.0.5 (March 18, 2026)
== React Server Components
- Add more cycle protections (@eps1lon, @unstubbable [#36236](https://github.com/facebook/react/pull/36236))
== 19.0.4 (Jan 26, 2026)
== React Server Components
- Add more DoS mitigations to Server Actions, and harden Server Components (@gnoff, @lubieowoce, @sebmarkbage, @unstubbable [#35632](https://github.com/facebook/react/pull/35632))
== 19.0.3 (Dec 11, 2025)
== React Server Components
- Add extra loop protection to React Server Functions (@sebmarkbage [#35351](https://github.com/facebook/react/pull/35351))
== 19.0.2 (Dec 11, 2025)
== React Server Components
- Patch Promise cycles and toString on Server Functions (@sebmarkbage, @unstubbable [#35289](https://github.com/facebook/react/pull/35289), [#35345](https://github.com/facebook/react/pull/35345))
== 19.0.1 (Dec 3, 2025)
== React Server Components
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
== 19.0.0 (December 5, 2024)
Below is a list of all new features, APIs, deprecations, and breaking changes. Read [React 19 release post](https://react.dev/blog/2024/04/25/react-19) and [React 19 upgrade guide](https://react.dev/blog/2024/04/25/react-19-upgrade-guide) for more information.
> Note: To help make the upgrade to React 19 easier, we’ve published a react@18.3 release that is identical to 18.2 but adds warnings for deprecated APIs and other changes that are needed for React 19. We recommend upgrading to React 18.3.1 first to help identify any issues before upgrading to React 19.
== New Features
== React
* Actions: `startTransition` can now accept async functions. Functions passed to `startTransition` are called “Actions”. A given Transition can include one or more Actions which update state in the background and update the UI with one commit. In addition to updating state, Actions can now perform side effects including async requests, and the Action will wait for the work to finish before finishing the Transition. This feature allows Transitions to include side effects like `fetch()` in the pending state, and provides support for error handling, and optimistic updates. * `useActionState`: is a new hook to order Actions inside of a Transition with access to the state of the action, and the pending state. It accepts a reducer that can call Actions, and the initial state used for first render. It also accepts an optional string that is used if the action is passed to a form `action` prop to support progressive enhancement in forms. * `useOptimistic`: is a new hook to update state while a Transition is in progress. It returns the state, and a set function that can be called inside a transition to “optimistically” update the state to expected final value immediately while the Transition completes in the background. When the transition finishes, the state is updated to the new value. * `use`: is a new API that allows reading resources in render. In React 19, `use` accepts a promise or Context. If provided a promise, `use` will suspend until a value is resolved. `use` can only be used in render but can be called conditionally. * `ref` as a prop: Refs can now be used as props, removing the need for `forwardRef`. * **Suspense sibling pre-warming**: When a component suspends, React will immediately commit the fallback of the nearest Suspense boundary, without waiting for the entire sibling tree to render. After the fallback commits, React will schedule another render for the suspended siblings to “pre-warm” lazy requests.
== React DOM Client
* `<form> action` prop: Form Actions allow you to manage forms automatically and integrate with `useFormStatus`. When a `<form> action` succeeds, React will automatically reset the form for uncontrolled components. The form can be reset manually with the new `requestFormReset` API. * `<button> and <input> formAction` prop: Actions can be passed to the `formAction` prop to configure form submission behavior. This allows using different Actions depending on the input. * `useFormStatus`: is a new hook that provides the status of the parent `<form> action`, as if the form was a Context provider. The hook returns the values: `pending`, `data`, `method`, and `action`. * Support for Document Metadata: We’ve added support for rendering document metadata tags in components natively. React will automatically hoist them into the `<head>` section of the document. * Support for Stylesheets: React 19 will ensure stylesheets are inserted into the `<head>` on the client before revealing the content of a Suspense boundary that depends on that stylesheet. * Support for async scripts: Async scripts can be rendered anywhere in the component tree and React will handle ordering and deduplication. * Support for preloading resources: React 19 ships with `preinit`, `preload`, `prefetchDNS`, and `preconnect` APIs to optimize initial page loads by moving discovery of additional resources like fonts out of stylesheet loading. They can also be used to prefetch resources used by an anticipated navigation.
== React DOM Server
* Added `prerender` and `prerenderToNodeStream` APIs for static site generation. They are designed to work with streaming environments like Node.js Streams and Web Streams. Unlike `renderToString`, they wait for data to load for HTML generation.
== React Server Components
* RSC features such as directives, server components, and server functions are now stable. This means libraries that ship with Server Components can now target React 19 as a peer dependency with a react-server export condition for use in frameworks that support the Full-stack React Architecture. The underlying APIs used to implement a React Server Components bundler or framework do not follow semver and may break between minors in React 19.x. See [docs](https://19.react.dev/reference/rsc/server-components) for how to support React Server Components.
== Deprecations
* Deprecated: `element.ref` access: React 19 supports ref as a prop, so we’re deprecating `element.ref` in favor of `element.props.ref`. Accessing will result in a warning. * `react-test-renderer`: In React 19, react-test-renderer logs a deprecation warning and has switched to concurrent rendering for web usage. We recommend migrating your tests to [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro)
== Breaking Changes
React 19 brings in a number of breaking changes, including the removals of long-deprecated APIs. We recommend first upgrading to `18.3.1`, where we've added additional deprecation warnings. Check out the [upgrade guide](https://19.react.dev/blog/2024/04/25/react-19-upgrade-guide) for more details and guidance on codemodding.
== React
* New JSX Transform is now required: We introduced [a new JSX transform](https://legacy.reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html) in 2020 to improve bundle size and use JSX without importing React. In React 19, we’re adding additional improvements like using ref as a prop and JSX speed improvements that require the new transform. * Errors in render are not re-thrown: Errors that are not caught by an Error Boundary are now reported to window.reportError. Errors that are caught by an Error Boundary are reported to console.error. We’ve introduced `onUncaughtError` and `onCaughtError` methods to `createRoot` and `hydrateRoot` to customize this error handling. * Removed: `propTypes`: Using `propTypes` will now be silently ignored. If required, we recommend migrating to TypeScript or another type-checking solution. * Removed: `defaultProps` for functions: ES6 default parameters can be used in place. Class components continue to support `defaultProps` since there is no ES6 alternative. * Removed: `contextTypes` and `getChildContext`: Legacy Context for class components has been removed in favor of the `contextType` API. * Removed: string refs: Any usage of string refs need to be migrated to ref callbacks. * Removed: Module pattern factories: A rarely used pattern that can be migrated to regular functions. * Removed: `React.createFactory`: Now that JSX is broadly supported, all `createFactory` usage can be migrated to JSX components. * Removed: `react-test-renderer/shallow`: This has been a re-export of [react-shallow-renderer](https://github.com/enzymejs/react-shallow-renderer) since React 18\. If needed, you can continue to use the third-party package directly. We recommend using [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro) instead.
== React DOM
* Removed: `react-dom/test-utils`: We’ve moved `act` from `react-dom/test-utils` to react. All other utilities have been removed. * Removed: `ReactDOM`.`render`, `ReactDOM`.`hydrate`: These have been removed in favor of the concurrent equivalents: `ReactDOM`.`createRoot` and `ReactDOM.hydrateRoot`. * Removed: `unmountComponentAtNode`: Removed in favor of `root.unmount()`. * Removed: `ReactDOM`.`findDOMNode`: You can replace `ReactDOM`.`findDOMNode` with DOM Refs.
== Notable Changes
== React
* `<Context>` as a provider: You can now render `<Context>` as a provider instead of `<Context.Provider>`. * Cleanup functions for refs: When the component unmounts, React will call the cleanup function returned from the ref callback. * `useDeferredValue` initial value argument: When provided, `useDeferredValue` will return the initial value for the initial render of a component, then schedule a re-render in the background with the `deferredValue` returned. * Support for Custom Elements: React 19 now passes all tests on [Custom Elements Everywhere](https://custom-elements-everywhere.com/). * StrictMode changes: `useMemo` and `useCallback` will now reuse the memoized results from the first render, during the second render. Additionally, StrictMode will now double-invoke ref callback functions on initial mount. * UMD builds removed: To load React 19 with a script tag, we recommend using an ESM-based CDN such as [esm.sh](http://esm.sh).
== React DOM
* Diffs for hydration errors: In the case of a mismatch, React 19 logs a single error with a diff of the mismatched content. * Compatibility with third-party scripts and extensions: React will now force a client re-render to fix up any mismatched content caused by elements inserted by third-party JS. == TypeScript Changes
The most common changes can be codemodded with `npx types-react-codemod@latest preset-19 ./path-to-your-react-ts-files`.
* Removed deprecated TypeScript types: * `ReactChild` (replacement: `React.ReactElement | number | string)` * `ReactFragment` (replacement: `Iterable<React.ReactNode>`) * `ReactNodeArray` (replacement: `ReadonlyArray<React.ReactNode>`) * `ReactText` (replacement: `number | string`) * `VoidFunctionComponent` (replacement: `FunctionComponent`) * `VFC` (replacement: `FC`) * Moved to `prop-types`: `Requireable`, `ValidationMap`, `Validator`, `WeakValidationMap` * Moved to `create-react-class`: `ClassicComponentClass`, `ClassicComponent`, `ClassicElement`, `ComponentSpec`, `Mixin`, `ReactChildren`, `ReactHTML`, `ReactSVG`, `SFCFactory` * Disallow implicit return in refs: refs can now accept cleanup functions. When you return something else, we can’t tell if you intentionally returned something not meant to clean up or returned the wrong value. Implicit returns of anything but functions will now error. * Require initial argument to `useRef`: The initial argument is now required to match `useState`, `createContext` etc * Refs are mutable by default: Ref objects returned from `useRef()` are now always mutable instead of sometimes being immutable. This feature was too confusing for users and conflicted with legit cases where refs were managed by React and manually written to. * Strict `ReactElement` typing: The props of React elements now default to `unknown` instead of `any` if the element is typed as `ReactElement` * JSX namespace in TypeScript: The global `JSX` namespace is removed to improve interoperability with other libraries using JSX. Instead, the JSX namespace is available from the React package: `import { JSX } from 'react'` * Better `useReducer` typings: Most `useReducer` usage should not require explicit type arguments. For example, ```diff
-useReducer<React.Reducer<State, Action>>(reducer)
+useReducer(reducer)
```
or
```diff
-useReducer<React.Reducer<State, Action>>(reducer)
+useReducer<State, Action>(reducer)
```
== All Changes
== React
* Add support for async Actions ([\#26621](https://github.com/facebook/react/pull/26621), [\#26726](https://github.com/facebook/react/pull/26726), [\#28078](https://github.com/facebook/react/pull/28078), [\#28097](https://github.com/facebook/react/pull/28097), [\#29226](https://github.com/facebook/react/pull/29226), [\#29618](https://github.com/facebook/react/pull/29618), [\#29670](https://github.com/facebook/react/pull/29670), [\#26716](https://github.com/facebook/react/pull/26716) by [@acdlite](https://github.com/acdlite) and [@sebmarkbage](https://github.com/sebmarkbage)) * Add `useActionState()` hook to update state based on the result of a Form Action ([\#27270](https://github.com/facebook/react/pull/27270), [\#27278](https://github.com/facebook/react/pull/27278), [\#27309](https://github.com/facebook/react/pull/27309), [\#27302](https://github.com/facebook/react/pull/27302), [\#27307](https://github.com/facebook/react/pull/27307), [\#27366](https://github.com/facebook/react/pull/27366), [\#27370](https://github.com/facebook/react/pull/27370), [\#27321](https://github.com/facebook/react/pull/27321), [\#27374](https://github.com/facebook/react/pull/27374), [\#27372](https://github.com/facebook/react/pull/27372), [\#27397](https://github.com/facebook/react/pull/27397), [\#27399](https://github.com/facebook/react/pull/27399), [\#27460](https://github.com/facebook/react/pull/27460), [\#28557](https://github.com/facebook/react/pull/28557), [\#27570](https://github.com/facebook/react/pull/27570), [\#27571](https://github.com/facebook/react/pull/27571), [\#28631](https://github.com/facebook/react/pull/28631), [\#28788](https://github.com/facebook/react/pull/28788), [\#29694](https://github.com/facebook/react/pull/29694), [\#29695](https://github.com/facebook/react/pull/29695), [\#29694](https://github.com/facebook/react/pull/29694), [\#29665](https://github.com/facebook/react/pull/29665), [\#28232](https://github.com/facebook/react/pull/28232), [\#28319](https://github.com/facebook/react/pull/28319) by [@acdlite](https://github.com/acdlite), [@eps1lon](https://github.com/eps1lon), and [@rickhanlonii](https://github.com/rickhanlonii)) * Add `use()` API to read resources in render ([\#25084](https://github.com/facebook/react/pull/25084), [\#25202](https://github.com/facebook/react/pull/25202), [\#25207](https://github.com/facebook/react/pull/25207), [\#25214](https://github.com/facebook/react/pull/25214), [\#25226](https://github.com/facebook/react/pull/25226), [\#25247](https://github.com/facebook/react/pull/25247), [\#25539](https://github.com/facebook/react/pull/25539), [\#25538](https://github.com/facebook/react/pull/25538), [\#25537](https://github.com/facebook/react/pull/25537), [\#25543](https://github.com/facebook/react/pull/25543), [\#25561](https://github.com/facebook/react/pull/25561), [\#25620](https://github.com/facebook/react/pull/25620), [\#25615](https://github.com/facebook/react/pull/25615), [\#25922](https://github.com/facebook/react/pull/25922), [\#25641](https://github.com/facebook/react/pull/25641), [\#25634](https://github.com/facebook/react/pull/25634), [\#26232](https://github.com/facebook/react/pull/26232), [\#26536](https://github.com/facebook/react/pull/26535), [\#26739](https://github.com/facebook/react/pull/26739), [\#28233](https://github.com/facebook/react/pull/28233) by [@acdlite](https://github.com/acdlite), [@MofeiZ](https://github.com/mofeiZ), [@sebmarkbage](https://github.com/sebmarkbage), [@sophiebits](https://github.com/sophiebits), [@eps1lon](https://github.com/eps1lon), and [@hansottowirtz](https://github.com/hansottowirtz)) * Add `useOptimistic()` hook to display mutated state optimistically during an async mutation ([\#26740](https://github.com/facebook/react/pull/26740), [\#26772](https://github.com/facebook/react/pull/26772), [\#27277](https://github.com/facebook/react/pull/27277), [\#27453](https://github.com/facebook/react/pull/27453), [\#27454](https://github.com/facebook/react/pull/27454), [\#27936](https://github.com/facebook/react/pull/27936) by [@acdlite](https://github.com/acdlite)) * Added an `initialValue` argument to `useDeferredValue()` hook ([\#27500](https://github.com/facebook/react/pull/27500), [\#27509](https://github.com/facebook/react/pull/27509), [\#27512](https://github.com/facebook/react/pull/27512), [\#27888](https://github.com/facebook/react/pull/27888), [\#27550](https://github.com/facebook/react/pull/27550) by [@acdlite](https://github.com/acdlite)) * Support refs as props, warn on `element.ref` access ([\#28348](https://github.com/facebook/react/pull/28348), [\#28464](https://github.com/facebook/react/pull/28464), [\#28731](https://github.com/facebook/react/pull/28731) by [@acdlite](https://github.com/acdlite)) * Support Custom Elements ([\#22184](https://github.com/facebook/react/pull/22184), [\#26524](https://github.com/facebook/react/pull/26524), [\#26523](https://github.com/facebook/react/pull/26523), [\#27511](https://github.com/facebook/react/pull/27511), [\#24541](https://github.com/facebook/react/pull/24541) by [@josepharhar](https://github.com/josepharhar), [@sebmarkbage](https://github.com/sebmarkbage), [@gnoff](https://github.com/gnoff) and [@eps1lon](https://github.com/eps1lon)) * Add ref cleanup function ([\#25686](https://github.com/facebook/react/pull/25686), [\#28883](https://github.com/facebook/react/pull/28883), [\#28910](https://github.com/facebook/react/pull/28910) by [@sammy-SC](https://github.com/sammy-SC), [@jackpope](https://github.com/jackpope), and [@kassens](https://github.com/kassens)) * Sibling pre-rendering replaced by sibling pre-warming ([\#26380](https://github.com/facebook/react/pull/26380), [\#26549](https://github.com/facebook/react/pull/26549), [\#30761](https://github.com/facebook/react/pull/30761), [\#30800](https://github.com/facebook/react/pull/30800), [\#30762](https://github.com/facebook/react/pull/30762), [\#30879](https://github.com/facebook/react/pull/30879), [\#30934](https://github.com/facebook/react/pull/30934), [\#30952](https://github.com/facebook/react/pull/30952), [\#31056](https://github.com/facebook/react/pull/31056), [\#31452](https://github.com/facebook/react/pull/31452) by [@sammy-SC](https://github.com/sammy-SC), [@acdlite](https://github.com/acdlite), [@gnoff](https://github.com/gnoff), [@jackpope](https://github.com/jackpope), [@rickhanlonii](https://github.com/rickhanlonii)) * Don’t rethrow errors at the root ([\#28627](https://github.com/facebook/react/pull/28627), [\#28641](https://github.com/facebook/react/pull/28641) by [@sebmarkbage](https://github.com/sebmarkbage)) * Batch sync discrete, continuous, and default lanes ([\#25700](https://github.com/facebook/react/pull/25700) by [@tyao1](https://github.com/tyao1)) * Switch `<Context>` to mean `<Context.Provider>` ([\#28226](https://github.com/facebook/react/pull/28226) by [@gaearon](https://github.com/gaearon)) * Changes to *StrictMode* * Handle `info`, `group`, and `groupCollapsed` in *StrictMode* logging ([\#25172](https://github.com/facebook/react/pull/25172) by [@timneutkens](https://github.com/timneutkens)) * Refs are now attached/detached/attached in *StrictMode* ([\#25049](https://github.com/facebook/react/pull/25049) by [@sammy-SC](https://github.com/sammy-SC)) * Fix `useSyncExternalStore()` hydration in *StrictMode* ([\#26791](https://github.com/facebook/react/pull/26791) by [@sophiebits](https://github.com/sophiebits)) * Always trigger `componentWillUnmount()` in *StrictMode* ([\#26842](https://github.com/facebook/react/pull/26842) by [@tyao1](https://github.com/tyao1)) * Restore double invoking `useState()` and `useReducer()` initializer functions in *StrictMode* ([\#28248](https://github.com/facebook/react/pull/28248) by [@eps1lon](https://github.com/eps1lon)) * Reuse memoized result from first pass ([\#25583](https://github.com/facebook/react/pull/25583) by [@acdlite](https://github.com/acdlite)) * Fix `useId()` in *StrictMode* ([\#25713](https://github.com/facebook/react/pull/25713) by [@gnoff](https://github.com/gnoff)) * Add component name to *StrictMode* error messages ([\#25718](https://github.com/facebook/react/pull/25718) by [@sammy-SC](https://github.com/sammy-SC)) * Add support for rendering BigInt ([\#24580](https://github.com/facebook/react/pull/24580) by [@eps1lon](https://github.com/eps1lon)) * `act()` no longer checks `shouldYield` which can be inaccurate in test environments ([\#26317](https://github.com/facebook/react/pull/26317) by [@acdlite](https://github.com/acdlite)) * Warn when keys are spread with props ([\#25697](https://github.com/facebook/react/pull/25697), [\#26080](https://github.com/facebook/react/pull/26080) by [@sebmarkbage](https://github.com/sebmarkbage) and [@kassens](https://github.com/kassens)) * Generate sourcemaps for production build artifacts ([\#26446](https://github.com/facebook/react/pull/26446) by [@markerikson](https://github.com/markerikson)) * Improve stack diffing algorithm ([\#27132](https://github.com/facebook/react/pull/27132) by [@KarimP](https://github.com/KarimP)) * Suspense throttling lowered from 500ms to 300ms ([\#26803](https://github.com/facebook/react/pull/26803) by [@acdlite](https://github.com/acdlite)) * Lazily propagate context changes ([\#20890](https://github.com/facebook/react/pull/20890) by [@acdlite](https://github.com/acdlite) and [@gnoff](https://github.com/gnoff)) * Immediately rerender pinged fiber ([\#25074](https://github.com/facebook/react/pull/25074) by [@acdlite](https://github.com/acdlite)) * Move update scheduling to microtask ([\#26512](https://github.com/facebook/react/pull/26512) by [@acdlite](https://github.com/acdlite)) * Consistently apply throttled retries ([\#26611](https://github.com/facebook/react/pull/26611), [\#26802](https://github.com/facebook/react/pull/26802) by [@acdlite](https://github.com/acdlite)) * Suspend Thenable/Lazy if it's used in React.Children ([\#28284](https://github.com/facebook/react/pull/28284) by [@sebmarkbage](https://github.com/sebmarkbage)) * Detect infinite update loops caused by render phase updates ([\#26625](https://github.com/facebook/react/pull/26625) by [@acdlite](https://github.com/acdlite)) * Update conditional hooks warning ([\#29626](https://github.com/facebook/react/pull/29626) by [@sophiebits](https://github.com/sophiebits)) * Update error URLs to go to new docs ([\#27240](https://github.com/facebook/react/pull/27240) by [@rickhanlonii](https://github.com/rickhanlonii)) * Rename the `react.element` symbol to `react.transitional.element` ([\#28813](https://github.com/facebook/react/pull/28813) by [@sebmarkbage](https://github.com/sebmarkbage)) * Fix crash when suspending in shell during `useSyncExternalStore()` re-render ([\#27199](https://github.com/facebook/react/pull/27199) by [@acdlite](https://github.com/acdlite)) * Fix incorrect “detected multiple renderers" error in tests ([\#22797](https://github.com/facebook/react/pull/22797) by [@eps1lon](https://github.com/eps1lon)) * Fix bug where effect cleanup may be called twice after bailout ([\#26561](https://github.com/facebook/react/pull/26561) by [@acdlite](https://github.com/acdlite)) * Fix suspending in shell during discrete update ([\#25495](https://github.com/facebook/react/pull/25495) by [@acdlite](https://github.com/acdlite)) * Fix memory leak after repeated setState bailouts ([\#25309](https://github.com/facebook/react/pull/25309) by [@acdlite](https://github.com/acdlite)) * Fix `useSyncExternalStore()` dropped update when state is dispatched in render phase ([\#25578](https://github.com/facebook/react/pull/25578) by [@pandaiolo](https://github.com/pandaiolo)) * Fix logging when rendering a lazy fragment ([\#30372](https://github.com/facebook/react/pull/30372) by [@tom-sherman](https://github.com/tom-sherman)) * Remove string refs ([\#25383](https://github.com/facebook/react/pull/25383), [\#28322](https://github.com/facebook/react/pull/28322) by [@eps1lon](https://github.com/eps1lon) and [@acdlite](https://github.com/acdlite)) * Remove Legacy Context (\#30319 by [@kassens](https://github.com/kassens)) * Remove `RefreshRuntime.findAffectedHostInstances` ([\#30538](https://github.com/facebook/react/pull/30538) by [@gaearon](https://github.com/gaearon)) * Remove client caching from `cache()` API ([\#27977](https://github.com/facebook/react/pull/27977), [\#28250](https://github.com/facebook/react/pull/28250) by [@acdlite](https://github.com/acdlite) and [@gnoff](https://github.com/gnoff)) * Remove `propTypes` ([\#28324](https://github.com/facebook/react/pull/28324), [\#28326](https://github.com/facebook/react/pull/28326) by [@gaearon](https://github.com/gaearon)) * Remove `defaultProps` support, except for classes ([\#28733](https://github.com/facebook/react/pull/28733) by [@acdlite](https://github.com/acdlite)) * Remove UMD builds ([\#28735](https://github.com/facebook/react/pull/28735) by [@gnoff](https://github.com/gnoff)) * Remove delay for non-transition updates ([\#26597](https://github.com/facebook/react/pull/26597) by [@acdlite](https://github.com/acdlite)) * Remove `createFactory` ([\#27798](https://github.com/facebook/react/pull/27798) by [@kassens](https://github.com/kassens))
== React DOM
* Adds Form Actions to handle form submission ([\#26379](https://github.com/facebook/react/pull/26379), [\#26674](https://github.com/facebook/react/pull/26674), [\#26689](https://github.com/facebook/react/pull/26689), [\#26708](https://github.com/facebook/react/pull/26708), [\#26714](https://github.com/facebook/react/pull/26714), [\#26735](https://github.com/facebook/react/pull/26735), [\#26846](https://github.com/facebook/react/pull/26846), [\#27358](https://github.com/facebook/react/pull/27358), [\#28056](https://github.com/facebook/react/pull/28056) by [@sebmarkbage](https://github.com/sebmarkbage), [@acdlite](https://github.com/acdlite), and [@jupapios](https://github.com/jupapios)) * Add `useFormStatus()` hook to provide status information of the last form submission ([\#26719](https://github.com/facebook/react/pull/26719), [\#26722](https://github.com/facebook/react/pull/26722), [\#26788](https://github.com/facebook/react/pull/26788), [\#29019](https://github.com/facebook/react/pull/29019), [\#28728](https://github.com/facebook/react/pull/28728), [\#28413](https://github.com/facebook/react/pull/28413) by [@acdlite](https://github.com/acdlite) and [@eps1lon](https://github.com/eps1lon)) * Support for Document Metadata. Adds `preinit`, `preinitModule`, `preconnect`, `prefetchDNS`, `preload`, and `preloadModule` APIs. * [\#25060](https://github.com/facebook/react/pull/25060), [\#25243](https://github.com/facebook/react/pull/25243), [\#25388](https://github.com/facebook/react/pull/25388), [\#25432](https://github.com/facebook/react/pull/25432), [\#25436](https://github.com/facebook/react/pull/25436), [\#25426](https://github.com/facebook/react/pull/25426), [\#25500](https://github.com/facebook/react/pull/25500), [\#25480](https://github.com/facebook/react/pull/25480), [\#25508](https://github.com/facebook/react/pull/25508), [\#25515](https://github.com/facebook/react/pull/25515), [\#25514](https://github.com/facebook/react/pull/25514), [\#25532](https://github.com/facebook/react/pull/25532), [\#25536](https://github.com/facebook/react/pull/25536), [\#25534](https://github.com/facebook/react/pull/25534), [\#25546](https://github.com/facebook/react/pull/25546), [\#25559](https://github.com/facebook/react/pull/25559), [\#25569](https://github.com/facebook/react/pull/25569), [\#25599](https://github.com/facebook/react/pull/25599), [\#25689](https://github.com/facebook/react/pull/25689), [\#26106](https://github.com/facebook/react/pull/26106), [\#26152](https://github.com/facebook/react/pull/26152), [\#26239](https://github.com/facebook/react/pull/26239), [\#26237](https://github.com/facebook/react/pull/26237), [\#26280](https://github.com/facebook/react/pull/26280), [\#26154](https://github.com/facebook/react/pull/26154), [\#26256](https://github.com/facebook/react/pull/26256), [\#26353](https://github.com/facebook/react/pull/26353), [\#26427](https://github.com/facebook/react/pull/26427), [\#26450](https://github.com/facebook/react/pull/26450), [\#26502](https://github.com/facebook/react/pull/26502), [\#26514](https://github.com/facebook/react/pull/26514), [\#26531](https://github.com/facebook/react/pull/26531), [\#26532](https://github.com/facebook/react/pull/26532), [\#26557](https://github.com/facebook/react/pull/26557), [\#26871](https://github.com/facebook/react/pull/26871), [\#26881](https://github.com/facebook/react/pull/26881), [\#26877](https://github.com/facebook/react/pull/26877), [\#26873](https://github.com/facebook/react/pull/26873), [\#26880](https://github.com/facebook/react/pull/26880), [\#26942](https://github.com/facebook/react/pull/26942), [\#26938](https://github.com/facebook/react/pull/26938), [\#26940](https://github.com/facebook/react/pull/26940), [\#26939](https://github.com/facebook/react/pull/26939), [\#27030](https://github.com/facebook/react/pull/27030), [\#27201](https://github.com/facebook/react/pull/27201), [\#27212](https://github.com/facebook/react/pull/27212), [\#27217](https://github.com/facebook/react/pull/27217), [\#27218](https://github.com/facebook/react/pull/27218), [\#27220](https://github.com/facebook/react/pull/27220), [\#27224](https://github.com/facebook/react/pull/27224), [\#27223](https://github.com/facebook/react/pull/27223), [\#27269](https://github.com/facebook/react/pull/27269), [\#27260](https://github.com/facebook/react/pull/27260), [\#27347](https://github.com/facebook/react/pull/27347), [\#27346](https://github.com/facebook/react/pull/27346), [\#27361](https://github.com/facebook/react/pull/27361), [\#27400](https://github.com/facebook/react/pull/27400), [\#27541](https://github.com/facebook/react/pull/27541), [\#27610](https://github.com/facebook/react/pull/27610), [\#28110](https://github.com/facebook/react/pull/28110), [\#29693](https://github.com/facebook/react/pull/29693), [\#29732](https://github.com/facebook/react/pull/29732), [\#29811](https://github.com/facebook/react/pull/29811), [\#27586](https://github.com/facebook/react/pull/27586), [\#28069](https://github.com/facebook/react/pull/28069) by [@gnoff](https://github.com/gnoff), [@sebmarkbage](https://github.com/sebmarkbage), [@acdlite](https://github.com/acdlite), [@kassens](https://github.com/kassens), [@sokra](https://github.com/sokra), [@sweetliquid](https://github.com/sweetliquid) * Add `fetchPriority` to `<img>` and `<link>` ([\#25927](https://github.com/facebook/react/pull/25927) by [@styfle](https://github.com/styfle)) * Add support for SVG `transformOrigin` prop ([\#26130](https://github.com/facebook/react/pull/26130) by [@arav-ind](https://github.com/arav-ind)) * Add support for `onScrollEnd` event ([\#26789](https://github.com/facebook/react/pull/26789) by [@devongovett](https://github.com/devongovett)) * Allow `<hr>` as child of `<select>` ([\#27632](https://github.com/facebook/react/pull/27632) by [@SouSingh](https://github.com/SouSingh)) * Add support for Popover API ([\#27981](https://github.com/facebook/react/pull/27981) by [@eps1lon](https://github.com/eps1lon)) * Add support for `inert` ([\#24730](https://github.com/facebook/react/pull/24730) by [@eps1lon](https://github.com/eps1lon)) * Add support for `imageSizes` and `imageSrcSet` ([\#22550](https://github.com/facebook/react/pull/22550) by [@eps1lon](https://github.com/eps1lon)) * Synchronously flush transitions in popstate events ([\#26025](https://github.com/facebook/react/pull/26025), [\#27559](https://github.com/facebook/react/pull/27559), [\#27505](https://github.com/facebook/react/pull/27505), [\#30759](https://github.com/facebook/react/pull/30759) by [@tyao1](https://github.com/tyao1) and [@acdlite](https://github.com/acdlite)) * `flushSync` exhausts queue even if something throws ([\#26366](https://github.com/facebook/react/pull/26366) by [@acdlite](https://github.com/acdlite)) * Throw error if `react` and `react-dom` versions don’t match ([\#29236](https://github.com/facebook/react/pull/29236) by [@acdlite](https://github.com/acdlite)) * Ensure `srcset` and `src` are assigned last on `<img>` instances ([\#30340](https://github.com/facebook/react/pull/30340) by [@gnoff](https://github.com/gnoff)) * Javascript URLs are replaced with functions that throw errors ([\#26507](https://github.com/facebook/react/pull/26507), [\#29808](https://github.com/facebook/react/pull/29808) by [@sebmarkbage](https://github.com/sebmarkbage) and [@kassens](https://github.com/kassens)) * Treat toggle and beforetoggle as discrete events ([\#29176](https://github.com/facebook/react/pull/29176) by [@eps1lon](https://github.com/eps1lon)) * Filter out empty `src` and `href` attributes (unless for `<a href=”” />`) ([\#18513](https://github.com/facebook/react/pull/18513), [\#28124](https://github.com/facebook/react/pull/28124) by [@bvaughn](https://github.com/bvaughn) and [@eps1lon](https://github.com/eps1lon)) * Fix unitless `scale` style property ([\#25601](https://github.com/facebook/react/pull/25601) by [@JonnyBurger](https://github.com/JonnyBurger)) * Fix `onChange` error message for controlled `<select>` ([\#27740](https://github.com/facebook/react/pull/27740) by [@Biki-das](https://github.com/Biki-das)) * Fix focus restore in child windows after element reorder ([\#30951](https://github.com/facebook/react/pull/30951) by [@ling1726](https://github.com/ling1726)) * Remove `render`, `hydrate`, `findDOMNode`, `unmountComponentAtNode`, `unstable_createEventHandle`, `unstable_renderSubtreeIntoContainer`, and `unstable_runWithPriority`. Move `createRoot` and `hydrateRoot` to `react-dom/client`. ([\#28271](https://github.com/facebook/react/pull/28271) by [@gnoff](https://github.com/gnoff)) * Remove `test-utils` ([\#28541](https://github.com/facebook/react/pull/28541) by [@eps1lon](https://github.com/eps1lon)) * Remove `unstable_flushControlled` ([\#26397](https://github.com/facebook/react/pull/26397) by [@kassens](https://github.com/kassens)) * Remove legacy mode ([\#28468](https://github.com/facebook/react/pull/28468) by [@gnoff](https://github.com/gnoff)) * Remove `renderToStaticNodeStream()` ([\#28873](https://github.com/facebook/react/pull/28873) by @gnoff) * Remove `unstable_renderSubtreeIntoContainer` ([\#29771](https://github.com/facebook/react/pull/29771) by [@kassens](https://github.com/kassens))
== React DOM Server
* Stable release of React Server Components ([Many, many PRs](https://github.com/facebook/react/pulls?q=is%3Apr+is%3Aclosed+%5BFlight%5D+in%3Atitle+created%3A%3C2024-12-01+) by [@sebmarkbage](https://github.com/sebmarkbage), [@acdlite](https://github.com/acdlite), [@gnoff](https://github.com/gnoff), [@sammy-SC](https://github.com/sammy-SC), [@gaearon](https://github.com/gaearon), [@sophiebits](https://github.com/sophiebits), [@unstubbable](https://github.com/unstubbable), [@lubieowoce](https://github.com/lubieowoce))
* Support Server Actions ([\#26124](https://github.com/facebook/react/pull/26124), [\#26632](https://github.com/facebook/react/pull/26632), [\#27459](https://github.com/facebook/react/pull/27459) by [@sebmarkbage](https://github.com/sebmarkbage) and [@acdlite](https://github.com/acdlite)) * Changes to SSR * Add external runtime which bootstraps hydration on the client for binary transparency ([\#25437](https://github.com/facebook/react/pull/25437), [\#26169](https://github.com/facebook/react/pull/26169), [\#25499](https://github.com/facebook/react/pull/25499) by [@MofeiZ](https://github.com/mofeiZ) and [@acdlite](https://github.com/acdlite)) * Support subresource integrity for `bootstrapScripts` and `bootstrapModules` ([\#25104](https://github.com/facebook/react/pull/25104) by [@gnoff](https://github.com/gnoff)) * Fix null bytes written at text chunk boundaries ([\#26228](https://github.com/facebook/react/pull/26228) by [@sophiebits](https://github.com/sophiebits)) * Fix logic around attribute serialization ([\#26526](https://github.com/facebook/react/pull/26526) by [@gnoff](https://github.com/gnoff)) * Fix precomputed chunk cleared on Node 18 ([\#25645](https://github.com/facebook/react/pull/25645) by [@feedthejim](https://github.com/feedthejim)) * Optimize end tag chunks ([\#27522](https://github.com/facebook/react/pull/27522) by [@yujunjung](https://github.com/yujunjung)) * Gracefully handle suspending in DOM configs ([\#26768](https://github.com/facebook/react/pull/26768) by [@sebmarkbage](https://github.com/sebmarkbage)) * Check for nullish values on ReactCustomFormAction ([\#26770](https://github.com/facebook/react/pull/26770) by [@sebmarkbage](https://github.com/sebmarkbage)) * Preload `bootstrapModules`, `bootstrapScripts`, and update priority queue ([\#26754](https://github.com/facebook/react/pull/26754), [\#26753](https://github.com/facebook/react/pull/26753), [\#27190](https://github.com/facebook/react/pull/27190), [\#27189](https://github.com/facebook/react/pull/27189) by [@gnoff](https://github.com/gnoff)) * Client render the nearest child or parent suspense boundary if replay errors or is aborted ([\#27386](https://github.com/facebook/react/pull/27386) by [@sebmarkbage](https://github.com/sebmarkbage)) * Don't bail out of flushing if we still have pending root tasks ([\#27385](https://github.com/facebook/react/pull/27385) by [@sebmarkbage](https://github.com/sebmarkbage)) * Ensure Resumable State is Serializable ([\#27388](https://github.com/facebook/react/pull/27388) by [@sebmarkbage](https://github.com/sebmarkbage)) * Remove extra render pass when reverting to client render ([\#26445](https://github.com/facebook/react/pull/26445) by [@acdlite](https://github.com/acdlite)) * Fix unwinding context during selective hydration ([\#25876](https://github.com/facebook/react/pull/25876) by [@tyao1](https://github.com/tyao1)) * Stop flowing and then abort if a stream is cancelled ([\#27405](https://github.com/facebook/react/pull/27405) by [@sebmarkbage](https://github.com/sebmarkbage)) * Pass cancellation reason to abort ([\#27536](https://github.com/facebook/react/pull/27536) by [@sebmarkbage](https://github.com/sebmarkbage)) * Add `onHeaders` entrypoint option ([\#27641](https://github.com/facebook/react/pull/27641), [\#27712](https://github.com/facebook/react/pull/27712) by [@gnoff](https://github.com/gnoff)) * Escape `<style>` and `<script>` textContent to enable rendering inner content without dangerouslySetInnerHTML ([\#28870](https://github.com/facebook/react/pull/28870), [\#28871](https://github.com/facebook/react/pull/28871) by [@gnoff](https://github.com/gnoff)) * Fallback to client replaying actions for Blob serialization ([\#28987](https://github.com/facebook/react/pull/28987) by [@sebmarkbage](https://github.com/sebmarkbage)) * Render Suspense fallback if boundary contains new stylesheet during sync update ([\#28965](https://github.com/facebook/react/pull/28965) by [@gnoff](https://github.com/gnoff)) * Fix header length tracking (\#30327 by [@gnoff](https://github.com/gnoff)) * Use `srcset` to trigger load event on mount (\#30351 by [@gnoff](https://github.com/gnoff)) * Don't perform work when closing stream (\#30497 by [@gnoff](https://github.com/gnoff)) * Allow aborting during render (\#30488, [\#30730](https://github.com/facebook/react/pull/30730) by [@gnoff](https://github.com/gnoff)) * Start initial work immediately (\#31079 by [@gnoff](https://github.com/gnoff)) * A transition flowing into a dehydrated boundary no longer suspends when showing fallback ([\#27230](https://github.com/facebook/react/pull/27230) by [@acdlite](https://github.com/acdlite)) * Fix selective hydration triggers false update loop error ([\#27439](https://github.com/facebook/react/pull/27439) by [@acdlite](https://github.com/acdlite)) * Warn for Child Iterator of all types but allow Generator Components ([\#28853](https://github.com/facebook/react/pull/28853) by [@sebmarkbage](https://github.com/sebmarkbage)) * Include regular stack trace in serialized errors ([\#28684](https://github.com/facebook/react/pull/28684), [\#28738](https://github.com/facebook/react/pull/28738) by [@sebmarkbage](https://github.com/sebmarkbage)) * Aborting early no longer infinitely suspends ([\#24751](https://github.com/facebook/react/pull/24751) by [@sebmarkbage](https://github.com/sebmarkbage)) * Fix hydration warning suppression in text comparisons ([\#24784](https://github.com/facebook/react/pull/24784) by [@gnoff](https://github.com/gnoff)) * Changes to error handling in SSR
* Add diffs to hydration warnings ([\#28502](https://github.com/facebook/react/pull/28502), [\#28512](https://github.com/facebook/react/pull/28512) by [@sebmarkbage](https://github.com/sebmarkbage)) * Make Error creation lazy ([\#24728](https://github.com/facebook/react/pull/24728) by [@sebmarkbage](https://github.com/sebmarkbage)) * Remove recoverable error when a sync update flows into a dehydrated boundary ([\#25692](https://github.com/facebook/react/pull/25692) by [@sebmarkbage](https://github.com/sebmarkbage)) * Don't "fix up" mismatched text content with suppressedHydrationWarning ([\#26391](https://github.com/facebook/react/pull/26391) by [@sebmarkbage](https://github.com/sebmarkbage)) * Fix component stacks in errors ([\#27456](https://github.com/facebook/react/pull/27456) by [@sebmarkbage](https://github.com/sebmarkbage)) * Add component stacks to `onError` ([\#27761](https://github.com/facebook/react/pull/27761), [\#27850](https://github.com/facebook/react/pull/27850) by [@gnoff](https://github.com/gnoff) and [@sebmarkbage](https://github.com/sebmarkbage)) * Throw hydration mismatch errors once ([\#28502](https://github.com/facebook/react/pull/28502) by [@sebmarkbage](https://github.com/sebmarkbage)) * Add Bun streaming server renderer ([\#25597](https://github.com/facebook/react/pull/25597) by [@colinhacks](https://github.com/colinhacks)) * Add nonce support to bootstrap scripts ([\#26738](https://github.com/facebook/react/pull/26738) by [@danieltott](https://github.com/danieltott)) * Add `crossorigin` support to bootstrap scripts ([\#26844](https://github.com/facebook/react/pull/26844) by [@HenriqueLimas](https://github.com/HenriqueLimas)) * Support `nonce` and `fetchpriority` in preload links ([\#26826](https://github.com/facebook/react/pull/26826) by [@liuyenwei](https://github.com/liuyenwei)) * Add `referrerPolicy` to `ReactDOM.preload()` ([\#27096](https://github.com/facebook/react/pull/27096) by [@styfle](https://github.com/styfle)) * Add server condition for `react/jsx-dev-runtime` ([\#28921](https://github.com/facebook/react/pull/28921) by [@himself65](https://github.com/himself65)) * Export version ([\#29596](https://github.com/facebook/react/pull/29596) by [@unstubbable](https://github.com/unstubbable)) * Rename the secret export of Client and Server internals ([\#28786](https://github.com/facebook/react/pull/28786), [\#28789](https://github.com/facebook/react/pull/28789) by [@sebmarkbage](https://github.com/sebmarkbage)) * Remove layout effect warning on server ([\#26395](https://github.com/facebook/react/pull/26395) by [@rickhanlonii](https://github.com/rickhanlonii)) * Remove `errorInfo.digest` from `onRecoverableError` ([\#28222](https://github.com/facebook/react/pull/28222) by [@gnoff](https://github.com/gnoff))
== ReactTestRenderer
* Add deprecation error to `react-test-renderer` on web ([\#27903](https://github.com/facebook/react/pull/27903), [\#28904](https://github.com/facebook/react/pull/28904) by [@jackpope](https://github.com/jackpope) and [@acdlite](https://github.com/acdlite)) * Render with ConcurrentRoot on web ([\#28498](https://github.com/facebook/react/pull/28498) by [@jackpope](https://github.com/jackpope)) * Remove `react-test-renderer/shallow` export ([\#25475](https://github.com/facebook/react/pull/25475), [\#28497](https://github.com/facebook/react/pull/28497) by [@sebmarkbage](https://github.com/sebmarkbage) and [@jackpope](https://github.com/jackpope))
== React Reconciler
* Enable suspending commits without blocking render ([\#26398](https://github.com/facebook/react/pull/26398), [\#26427](https://github.com/facebook/react/pull/26427) by [@acdlite](https://github.com/acdlite)) * Remove `prepareUpdate` ([\#26583](https://github.com/facebook/react/pull/26583), [\#27409](http://github.com/facebook/react/pull/27409) by [@sebmarkbage](https://github.com/sebmarkbage) and [@sophiebits](https://github.com/sophiebits))
== React-Is
* Enable tree shaking ([\#27701](https://github.com/facebook/react/pull/27701) by [@markerikson](https://github.com/markerikson)) * Remove `isConcurrentMode` and `isAsyncMode` methods ([\#28224](https://github.com/facebook/react/pull/28224) by @gaearon)
== useSyncExternalStore
* Remove React internals access ([\#29868](https://github.com/facebook/react/pull/29868) by [@phryneas](https://github.com/phryneas)) * Fix stale selectors keeping previous store references ([\#25969](https://github.com/facebook/react/pull/25968) by [@jellevoost](https://github.com/jellevoost))
@types/react and @types/react-dom are published from DefinitelyTyped
and have no changelog.
Release notes:
- https://github.com/facebook/react/blob/main/CHANGELOG.md
- React 19 upgrade guide: https://react.dev/blog/2024/04/25/react-19-upgrade-guide
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment
7 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This lets you pass a function to
<form action={...}>or<button formAction={...}>or<input type="submit formAction={...}>. This will behave basically like ajavascript:URL except not quite implemented that way. This is a convenience for theonSubmit={e => { e.preventDefault(); const fromData = new FormData(e.target); ... }pattern.You can still implement a custom
onSubmithandler and if it callspreventDefault, it won't invoke the action, just like it would if you used a full page form navigation or javascript urls. It behaves just like a navigation and we might implement it with the Navigation API in the future.Currently this is just a synchronous function but in a follow up this will accept async functions, handle pending states and handle errors.
This is implemented by setting
javascript:URLs, but these only exist to trigger an error message if something goes wrong instead of navigating away. Like if you calledstopPropagationto prevent React from handling it or if you calledform.submit()instead ofform.requestSubmit()which by-passes thesubmitevent. If CSP is used to banjavascript:urls, those will trigger errors when these URLs are invoked which would be a different error message but it's still there to notify the user that something went wrong in the plumbing.Next up is improving the SSR state with action replaying and progressive enhancement.