Package detail

effector

effector235.2kMIT23.4.4

Business logic with ease

business, logic, data, flow, state management, state manager, algebraic effects, model, reactive, state, frp, event, effect, functional, store

readme

☄️ effector

Business logic with ease

Visit effector.dev for docs, guides and examples

Introduction
- Effector follows five basic principles:
Installation
Documentation
Packages
Articles
Community
Online playground
DevTools
More examples in documentation
Learn more
Support us
Contributors

Introduction

Effector implements business logic with ease for Javascript apps (React/React Native/Vue/Svelte/Node.js/Vanilla), allows you to manage data flow in complex applications. Effector provides best TypeScript support out of the box.

Effector follows five basic principles:

Application stores should be as light as possible - the idea of adding a store for specific needs should not be frightening or damaging to the developer.
Application stores should be freely combined - data that the application needs can be statically distributed, showing how it will be converted in runtime.
Autonomy from controversial concepts - no decorators, no need to use classes or proxies - this is not required to control the state of the application and therefore the api library uses only functions and plain js objects
Predictability and clarity of API - a small number of basic principles are reused in different cases, reducing the user's workload and increasing recognition. For example, if you know how .watch works for events, you already know how .watch works for stores.
The application is built from simple elements - space and way to take any required business logic out of the view, maximizing the simplicity of the components.

Installation

You can use any package manager

npm add effector

React

To getting started read our article how to write React and Typescript application.

npm add effector effector-react

SolidJS

npm add effector effector-solid

Vue

npm add effector effector-vue

Svelte

Svelte works with effector out of the box, no additional packages needed. See word chain game application written with svelte and effector.

CDN

Documentation

For additional information, guides and api reference visit our documentation site

Packages

Articles

Community

official
awesome-effector a curated list of awesome effector packages, videos and articles
Twitter
Telegram (@effector_en)
Telegram 🇷🇺 (@effector_ru)
dev.to
Discord
Add a GitHub Topic effector to your project's home page

Online playground

You can try effector with online playground

Code sharing, Typescript and react supported out of the box. Playground repository

DevTools

Use effector-logger for printing updates to console, displaying current store values with ui or connecting application to familiar redux devtools

Learn more

Support us

Read more articles on a patreon page
Donate on OpenCollective
Be a sponsor on Github Sponsors

Your support allows us to improve the developer experience 🧡.

Contributors

_Dmitry	_{andretshurotshka}	_Sova	_{Alexander Khoroshikh}	_popuguy	_{Igor Kamyşev}
_pxbuffer	_{Valeriy Kobzar}	_Yan	_{Ruslan @doasync}	_{Illia Osmanov}	_mg901
_{Igor Ryzhov}	_{Nikita Kungurcev}	_{Edward Gigolaev}	_Viktor	_{Arthur Irgashev}	_Ilya
_Ainur	_{Ilya Olovyannikov}	_{Mikhail Kireev}	_{Arutyunyan Artem}	_{Dmitrij Shuleshov}	_{Nikita Nafranets}
_{Ivan Savichev}	_{Aleksandr Osipov}	_bakugod	_{Зухриддин Камильжанов}	_{Mikhail Krilov}	_{Victor Didenko}
_{Viktor Pasynok}	_{Kirill Mironov}	_Andrei	_Denis	_{Filipkin Denis}	_Ivan
_{Ivanov Vadim}	_sergey20x25	_Rastrapon	_Dan	_{Bohdan Petrov}	_{Bartłomiej Wendt}
_{Andrei Antropov}	_☃︎	_xaota	_cqh	_{Aldiyar Batyrbekov}	_{Vladimir Ivakin}
_{Vitaly Afonin}	_Victor	_{Tauyekel Kunzhol}	_Ivan	_Sozonov	_Samir
_{Renat Sagdeev}	_Kirill	_{Denis Sikuler}	_{Chshanovskiy Maxim}	_Arsen-95	_{Anton Yurovskykh}
_{Anton Kosykh}	_{Aleksandr Belov}	_{Usman Yunusov}	_{Vasili Sviridov}	_{Vasili Svirydau}	_{Victor Kolb}
_Vladislav	_{Vladislav Melnikov}	_{Vladislav Botvin}	_{Will Heslam}	_xxxxue	_{The Gitter Badger}
_{Simon Muravev}	_Shiyan7	_{Sergey Belozyorcev}	_{Satya Rohith}	_{Roman Paravaev}	_Roman
_{Robert Kuzhin}	_{Raman Aktsisiuk}	_{Rachael Dawn}	_{vladthelittleone}	_Vladimir	_roman
_Eris	_lightningmq	_{Kirill Leushkin}	_kanno	_Ilya	_ilfey
_{Houston (Bot)}	_{Grigory Zaripov}	_{dmitryplyaskin}	_Stanislav	_{Артём Жолудь}	_ansunrisein
_{Anatoly Kopyl}	_{Yesset Zhussupov}	_Rasul	_bigslycat	_{Dmitry Dudin}	_Dmitry
_{Denis Skiba}	_{Dinislam Maushov}	_Ayu	_David	_{Egor Gorochkin}	_{Amar Sood}
_{Александр}	_Alexander	_{Alex Anokhin}	_jokecodes	_{Alex Arro}	_{Aleksandr Grigorii}
_{Abel Soares Siqueira}	_7iomka	_{Abdukerim Radjapov}	_0xflotus	_{Pavel Hrakovich}	_Oleh
_Oleg	_{Mike Cann}	_{Nikita Svoyachenko}	_{Marco Pasqualetti}	_{Ludovic Dem}	_Leniorko
_{Lebedev Konstantin}	_{Joel Bandi}	_{Jesse Jackson}	_{Jan Keromnes}	_Ivan	_{Infant Frontender}
_{Ilya Martynov}	_{Gleb Kotovsky}	_{Gabriel Husek}	_{Ed Prince}

changelog

Changelog

effector 23.4.4

Add enable_debug_traces compilation to debug files

effector 23.4.3

Make effector/enable_debug_traces actually built for production bundle

effector 23.4.2

Turn off debug traces by default, enable by designated api PR, Docs

effector 23.4.1

Fix sample name support for cases without plugin

effector 23.4.0

Babel/SWC plugin

Add support for hmr. Big thanks to @movpushmov and @kireevmp
Add support for transformLegacyDomainMethods option PR #1059
Add forceScope option (PR #1002)
Add effector-action to default factories
Add support for tagged template factories (like patronum format)

Typings

Improve split typings (PR #1253), fixes issues #622 #769 and #999. Big thanks to @den-churbanov for handling these insurmountable typings 💪
Add skipVoid to type of domain.createStore (PR #1262)

Runtime

Add better support for name field in sample for improved patronum.debug({trace: true}) logs (issue #1268)

effector 23.3.0

Improve error messages: now errors for skipVoid and store without sid will point to the line of store creation. This will help locate troublesome units easily
Add support for multiple arguments to scopeBind. This feature indirectly allows to use multiple arguments in reflect (issue reflect#91)
Fix issues with clearNode (issue #1200)

effector-vue 23.1.1

Fix Date suppport in useVModel, createGate and options API (PR #1228, thanks egoson)

effector-react 23.3.0

Add react 19 support

effector-vue 23.1.0

Update useVModel bindings (issue #1150)
Add support for options api for vue 3 (useful for large codebase migration from vue 2) (issue #1178)

Big thanks to egoson for making this release possible

effector 23.2.3

Fix types for attach({ effect }), allowing to pass explicit name in this overload (issue #1000)

effector 23.2.2

Fix types for createEffect and attach in factories with generics (issue #1069). Cases like this now works correctly:

function createModel<T>() {
  const $data = createStore<T | null>(null)
  const fx = createEffect(() => null as T)
  sample({clock: fx.doneData, target: $data})
}

effector-react 23.2.1

Fix types for useUnit([fx]) with effect with custom error (PR #1070)

effector 23.2.1

Fix forbidden keys in combine (issue #1064)

effector-react 23.2.0

Make Gate.open and Gate.close EventCallable to allow users to call it in tests

effector 23.2.0

Improve type validation for derived stores in fork
Add missed runtime validation for allSettled calls with derived units. This case was labeled as a type error, but was forgotten in runtime.

effector 23.1.0

Support arbitary callbacks in scopeBind. Allows library developers to create better APIs in a way that is Fork API - compatible. PR #1016
Remove deprecated types for already removed $store.map overload. PR #1029

effector-react 23.1.0

Skip enumerable prototype-inherited properties in useUnit(shape). Some badly-written polyfills might add such properties to built-ins like Array. PR #1023
Add missing depreaction tag to the one of useEvent overloads. PR #1030
Add useProvidedScope low level API for library developers. PR #1033

effector-react 23.0.1

Fix warning about useStore appeared in useList (PR #1022)

effector 23.0.0 Spacewatch

Improvements

Introduce EventCallable, StoreWritable and UnitTargetable types to allow users to express and understand what could be updated or called directly and what could not. Now createStore returns StoreWritable which can be passed to sample target and combine returns Store which will show type and runtime error (PR #966)
Improve error messages: now it includes unit names and locations so it will be useful to find errors in raw server logs or bundles with disabled source maps. To enable locations in errors use addLoc: true in babel-plugin. Usually the one wanted to enable this in development only so addLoc plugin option is disabled by default (PR #1015)
Add batch option to createWatch (PR #850)
Add @withease/factories to babel-plugin defaults (PR #995)
Add all patronum modules to babel-plugin defaults (PR #996)
Rename greedy to batch in sample. greedy: true becomes batch: false which is a better mental model for what this option do (PR #972)
Unify programmatic sid insertion in merge and restore (PR #969)
Allow domain to be used in attach without parent effect (PR #895)

Bug fixes

Fix nullable type of .reinit, now it exists in StoreWritable and not exists in Store (PR #966)
Fix serialization of ignored stores (PR #903)
Fix race condition in parallel effect calls (PR #849)
Fix scope reading its initial values from current (not initial) store value (PR #909)
Fix duplicated combine calls (PR #916)
Fix reading stale value in attach (PR #1011)

Deprecations and removed apis

Deprecate undefined as magical value to skip store updates, use skipVoid: true option in combine and map to enable old behavior. Getting rid of that edge case will allow to introduce lazy computations (issue #920)
Deprecate forward and guard in favor of sample (PR #913)
Deprecate reactSsr option in babel-plugin (PR #910)
Deprecate onlyChanges option in serialize (PR #907)
Deprecate raw object {[fx.sid]: Function} in fork handlers (PR #973)
Deprecate .watch with second argument in favor of sample (PR #906)
Deprecate .getType() - relic from ancient times which exists for redux compatibility (PR #899)
Deprecate effector/babel-plugin-react (PR #948)
Deprecate fork(domain) and hydrate(domain) - this api existed for traking units in scopes when Fork API was introduced, but starting from 22 version this is done automatically and domain is no longer required for that (PR #950)

Throw error when unit called from a pure function (PR #905)
Throw error when derived event is called (PR #905)
Throw error when fn in $store.map(fn) returns undefined in the initialization (issue #828)

Remove flow typings. In the beginning, the effector was written in flow, but now only types remained and they were extremely outdated due to lack of expertise in the technology. The flow community maintains bindings in a separate repository. (PR #912)
Remove deprecated effector/fork module (PR #842)
Remove deprecated createStoreObject alias for combine (PR #908)
Remove deprecated .thru method (PR #843)
Remove deprecated second argument with state from $store.map (PR #846)
Remove deprecated restore($store) support. This was an obscure feature when store is passed to method and returned without changes as is (PR #1018)

Performance

10% performance improvement (PR #1014)

effector-react 23.0.0

Deprecate effector-react/scope in favor of isomorphic hooks (PR #979)
Deprecate useStore, useEvent, connect and createStoreConsumer in favor of universal useUnit (PR #951)
Deprecate createComponent in favor of @effector/reflect
Remove deprecated effector-react/ssr module (PR #844)
Remove deprecated createReactState and createContextComponent (PR #845)

effector-solid 0.23.0

Make all hooks isomorphic
Deprecate effector-solid/scope in favor of isomorphic hooks (PR #979)

effector-vue 23.0.0

Add useUnit hook (PR #1003)
Make bindings isomorphic
Deprecate effector-vue/ssr in favor of isomorphic hooks (PR #1005)
Remove obsolete deprecated apis $watchAsStore and $store (PR #1004)

effector 22.8.8

Add new types from effector 23: UnitTargetable, EventCallable and StoreWritable as aliases to improve migration experience and ecosystem compatibility

effector 22.8.7

Fix combine function called twice on first allSettled call (PR #984)

effector-react 22.5.4

Fix for createWatch implementation to improve @effector/next updates flow

effector-react 22.5.3

Fix too frequent useUnit updates

effector 22.8.6

Follow-up fix for 22.8.2: now combine in tuple-form handles compelx edge-cases with mapped stores correctly. (PR #902)

effector-react 22.5.2

Fix bug in useUnit during event change (issue #900, PR #901)

effector 22.8.5

Follow up fix for 22.8.4: now fix works for fork({ handlers }) calls too. PR #898

effector 22.8.4

Fixed an edge case for fork calls without sid (function from release 22.8.0). Some libraries provide built-in sid's in the code, which led to the duplicated sid found exception when calling fork when trying to use two instances of the same factory in a test and running it without effector/babel-plugin. The exception on fork calls is no longer thrown, and all sid-related checks and assertions have been moved to serialize calls, since sid's are actually only required for serialize to work. PR #897

effector 22.8.3

Added missing node and stateRef ids to meta-objects. These are internal changes which are not covered by the types or docs yet.

effector 22.8.2

combine types now allow primitive values, just like it was stated in the docs. Thanks to @faustienf PR #884
Events, created from split with match-object shape and internal inFlight counters of Effects now have proper metadata to use in the Inspect API. PR #892

effector 22.8.1

Internal state refs now also see meta, if owned by store. PR #889

effector 22.8.0

Sids are no longer required for fork({ values, handlers }), which allows to run tests without effector/babel-plugin. Note, that plugin and sids are still required for SSR. (PR #855)

effector-react 22.5.1

Fix Gate usage as component. <Gate /> will also be isomorphic by scope.

effector 22.7.0

Fix Declaration type, provide missing top-level properties for region and factory types
Add node's id to Declaration type

effector 22.6.2

Fix return type of withRegion

effector 22.6.1

Add missing exports definition for effector/inspect API

effector 22.6.0

Implemented inspect API (PR #859)

effector 22.5.2

Fix serialize: "ignore" in fork({ values }) (PR #862)

effector 22.5.1

Fix default factories list in babel-plugin (PR #857)

effector-react 22.5.0

Make useGate isomorphic in effector-react module, so the one not needed to use effector-react/scope anymore (PR #852)
Fix useUnit hangs when scope is changed (happens when route is changed in next.js) (PR #851)

effector 22.5.0

Support allSettled(scope) feature.

effector-react 22.4.0

Support @@unitShape protocol (PR #803) in useUnit

effector-solid 0.22.7

Support @@unitShape protocol (PR #803) in useUnit

effector 22.4.1

Add type support for read only arrays in sample source. This case now supported and typechecked correctly:

const profileFormSubmitted = createEvent()
const $name = createStore('alice')
const $age = createStore(0)
const saveProfileFx = createEffect(async ([name, age]: [string, number]) => {})

sample({
  clock: profileFormSubmitted,
  source: [$name, $age] as const,
  target: saveProfileFx,
})

Note that the one need to use "as const" in that case to got correct typechecking because without it typescript cannot infer the type [Store<string>, Store<number>]. We are working to avoid that limitation, stay tuned!

effector Encke 22.4.0

Add custom serializers for Store (PR #744)
Allow to pass domain as an argument for createEvent and similar methods (PR #763)
Add store.reinit event to set default value into store (PR #797)

const $store = createStore<Array<number>>([])

sample({
  clock: someEffectFailed,
  target: $store.reinit,
})

// subscribe on store reinit
sample({
  clock: $store.reinit,
  fn: createEffect(() => console.log('store value set to default')),
})

Add safe mode for scopeBind (PR #688)
Add is.attached method to detect effects created via attach (PR #670)
Add @farfetched/core and atomic-router to default factories so the one not needed to describe them explicitly
Protect against combine argument being broken via Array.slice (PR #801)
Add "type" entry for package exports (PR #759)
Finally allow Gate to be serialized (as this requires changes in babel plugin) (PR #683)

effector-react 22.3.4

Fix useUnit skipping updates when used with useEffect and useGate

effector-react 22.3.3

Fix useUnit skipping updates during scope changes (often happens in next.js apps). Big thanks to @AlexandrHoroshih for investigation

effector-react 22.3.1

Fix useUnit skipping updates in react 16-17

effector-vue 22.2.0

Add useStoreMap hook for Vue 3 composition API to select part from a store ((PR #780)[https://github.com/effector/effector/pull/780]) by @ilajosmanov

effector-react 22.3.0

Made hooks useEvent, useStore, useStoreMap and useList isomorphic, now they would use scope from the Provider if it is available and scope-less mode otherwise. For useUnit it was done in 22.2.0.
Added parameter forceScope to useEvent, useStore, useStoreMap and useList to force usage of scope from Provider, it would throw an error if Provider is not available, /scope module sets forceScope to true by default

effector-solid 0.22.6

Add type of Provider to main module

effector-solid 0.22.5

Add export of Provider from main module

effector-react 22.2.0

Made hook useUnit isomorphic, now it would use scope from the Provider if it is available and scope-less mode otherwise (PR #776 and PR #785)
Added parameter forceScope to useUnit to force usage of scope from Provider, it would throw an error if Provider is not available (PR #776 and PR #785), /scope module sets forceScope to true by default
Added "type" entry for package exports (PR #759)
Fixed typing in useUnit (PR #747)

effector-solid 0.22.4

Made useUnit isomorphic, now it would use scope from the Provider if it is available and scope-less mode otherwise (PR #782)
Added parameter forceScope to useUnit to force usage of scope from Provider, it would throw an error if Provider is not available (PR #782), /scope module sets forceScope to true by default

effector-vue 22.1.2

Added "type" entry for package exports (PR #759)

effector-solid 0.22.3

Added "type" entry for package exports (PR #759)

effector-solid 0.22.2

Fixed typing in useUnit (PR #747)

forest 0.21.2

Added "type" entry for package exports (PR #759)

effector-react 22.1.0

Added support for react 18 (PR #655)
Added useUnit method to read multiple stores and bind events or effects to scope in a single batched call (PR #733, #738)

import {value createEvent, value createStore, value fork} from 'effector'
import {value useUnit, value Provider} from 'effector-react/scope'

const inc = createEvent()
const $count = createStore(0)
const $title = createStore('useStore example')

$count.on(inc, x => x + 1)

const App = () => {
  const [count, title, incFn] = useUnit([$count, $title, inc])
  return (
    <>
      <h1>{title}</h1>
      <p>Count: {count}</p>
      <button onClick={() => incFn()}>increment</button>
    </>
  )
}

const scope = fork()

render(
  () => (
    <Provider value={scope}>
      <App />
    </Provider>
  ),
  document.getElementById('root'),
)

Added placeholder option to useList to render in cases of empty list

const ChatList = () => (
  <div>
    {useList($chats, {
      fn: chat => <div>Chat {chat.name}</div>,
      keys: [],
      placeholder: <div>You have no chats yet. Add first one?</div>,
    })}
  </div>
)

Added defaultValue option to useStoreMap to return in cases when fn returns undefined

const ChatName = ({id}) => {
  const chat = useStoreMap({
    store: $chats,
    keys: [id],
    fn: chats => chats.find(chat => chat.id === id),
    defaultValue: {id: 'default', name: 'Default chat'},
  })
  return <span>{chat.name}</span>
}

Fixed Gate.status store being serialized (PR #683)

effector 22.2.0

Added filter option to sample, thereby making guard an alias (issue #521)

sample({
  clock: submitPasswordEvent,
  source: $store,
  filter: (state: AuthFlowState) => state is WaitingPasswordState,
  fn: (waitingPasswordState, clock) => waitingPasswordState.password,
  target: submitPassowrdFx,
})

Added clock option to split (issue #537)

split({
  clock: submit,
  source: $form,
  match: $mode,
  cases: {
    draft: saveFormDraftFx,
    send: sendFormToBackendFx,
  },
})

Improved sample type checking:
- Fixed cases when target units becomes compatible with any type (issue #600)
- Fixed cases when method call being marked as error when it perfectly correct
- Removed vague "incompatible unit in target" error
- Error messages now explicitly tells which type is given by source and which one is expected by target
- 16 overloads was merged into single one to improve clarity of error messages. Will remove a lot of noise from IDE output thereby improving developer expirience
Improved split type checking:
- Fixed a case when units in cases becomes compatible with any type
- Removed vague "incompatible unit in target" error
- Error messages now explicitly tells which type is given by source and which one is expected by failed target case
Added jsdoc documentation for all top level methods. Will be used by IDE such as VS Code and Webstorm to provide better developer expirience
Derived units in target of sample, guard, split and forward are deprecated (issue #563)
Imperative calls of derived units created by merge, sample and split are deprecated
Imperative calls of events and effects in pure functions are deprecated (issue #541)
restore($store) is deprecated (issue #571)
Effects created by attach got correct name for use in developer tools like effector-logger (issue #527)
Fixed a case when sample/guard pass obsolete data from it's source store (issue #544)
Fixed data race when using combine with fork api (issue #613)
Fixed cases when effector/babel-plugin changes function calls which it should avoid (issue #603)
Fixed support for multiple passes of effector/babel-plugin (issue #601)
Fixed combine support for units with large union types (issue #531)
Fixed support for calls without payload for Event<unknown> (PR #454)
Fixed circular reference warning during import of typings (issue #578)

effector-vue 22.1.0

Add support for Vue 3 SSR via new useEvent hook and VueSSRPlugin (PR #595)

effector-react 22.0.6

Fix Can't perform a React state update on an unmounted component warning for useStoreMap in a few cases (issue #574)

effector 22.1.2

Allow to use effector/babel-plugin in patronum/macro

effector 22.1.1

Fix data races that cause obsolete states to appear in the .on and .reset methods

effector 22.1.0

Added option debugSids to effector/babel-plugin

The option allows adding file path and variable name to a sid for each unit definition. It allows to easily debug serialized scope using SSR.

effector 22.0.0

Add support for plain functions to attach: attach({source, async effect(source, params) {}})
Allow to use fork without domains: const scope = fork()
- Unit not found in scope error is no longer exists, any unit could be used in any scope
- Increase performance of fork and serialize a hundredfold
Add support for attached effects to fork handlers
Add support for tuples to fork values and handlers: fork({values: [[$user, 'alice'], [$age, 22]]})
Add serialize: 'ignore' option to createStore to declare store as ignored by serialize calls
Make onlyChanges: true a default serialize option
Fix babel plugin issue with parsing method calls (e.g. in react native)
Validate combine arguments and throw an error in case of undefined and non-store units (issue #509)
Throw an error when fork handlers or values got units without sid or with duplicate sid
Deprecate createStoreObject alias for combine
Deprecate effector/fork module
Deprecate .thru
Deprecate second argument in store.map
Deprecate direct manipulations with derived units:
- Deprecate .on in derived stores created by store.map and combine
- Deprecate calls of derived events created by event.map, event.filterMap and event.filter
- Deprecate calls of fx.done, fx.doneData and other events belongs to effects
Remove ɔ (latin small letter open o) symbol to prevent incorrect unicode parsing
Remove undocumented scope.find which is a wrong abstraction for a new fork
Make Scope a unit:
- Add support for Scope to is.unit
- Add is.scope method
Allow to pass a scope to scopeBind: scopeBind(unit, {scope}), which is also can be used outside from .watch
Improve es modules support
Make package size 10% smaller

effector-react 22.0.0

Add module effector-react/scope and make effector-react/ssr an alias for it
Fix Cannot update a component warning in useGate
Allow to return undefined in useStoreMap
Make domain field in createGate optional
Deprecate createContextComponent and createReactState
Improve es modules support

effector-vue 22.0.0

Improve es modules support

forest 0.20.0

Improve es modules support

effector-react 21.3.1

Fixed TypeError in useStoreMap with scope (PR #474)

effector-react 21.3.0

Add support for updateFilter to useStoreMap. It helps to control component rerendering, e.g. when component should rerender only when id field is changed
Add useStoreMap($store, value => result) shorthand
Add support for getKey to useList. Function in this field will be used to compute key for every item of list
Add support for stores with functions in them to useStore (PR #431)
Add domain name passed to createGate to gate.displayName and gate units (issue #449)
Fix unhandled promise rejection in useEvent when used effect throw an error

effector 21.8.0

Add type support for arrays in sample target (PR #284, #445)

sample({
  clock: clickValidate,
  source: $formFields,
  target: [validateForm, sendStatsFx],
})

Add support for case functions, case stores and matcher stores to split. Case functions and stores will choose target case by its name, matcher stores are boolean stores which indicate whether to choose given case

const source = createEvent()
const even = createEvent()

const $odd = createStore(0)

split({
  source,
  // case function
  match(n) {
    if (n % 2 === 0) return 'even'
    return 'odd'
  },
  cases: {
    even,
    odd: $odd,
  },
})

const $currentPage = createStore('dashboard')

split({
  source,
  // case store
  match: $currentPage,
  cases: {
    dashboard: even,
    __: odd,
  },
})

const tryUpdatePage = createEvent()
const updatePageFx = createEffect()

const $hasWriteAccess = createStore(false)

split({
  source: tryUpdatePage,
  match: {
    // matcher store
    admin: $hasWriteAccess,
  },
  cases: {
    admin: updatePageFx,
  },
})

Add updateFilter config field to createStore to skip arbitrary store updates (discussion #428)

const $playerPosition = createStore(
  {x: 0, y: 0},
  {
    updateFilter: (update, current) => update.x !== current.x,
  },
)

Add support for sample with clock without source. For example, it useful in cases when clock is array of units and no source stores is needed

sample({
  clock: [fx1.doneData, fx2.doneData],
  fn: data => ({url: '/stats', data})
  target: fetchFx,
})

Add support for clock to guard to improve developer expirience in cases when update trigger (clock field) and data source (source field) are different things

guard({
  clock: validateForm,
  source: $formFields,
  filter: formFields => validator(formFields),
  target: submitFormFx,
})

Add addNames field to babel plugin (PR #450)
Add type support for Scope to clearNode (issue #441)
Add compositeName to Domain typings, making it consistent with other units
Add EventPayload and UnitValue type helpers (PR #434)
Improve various edge cases with fork api and serialization
Improve typechecking for attach (issue #439)
Fix various type issues in sample and guard typings

effector-react 21.2.0

Add createGate implementation to effector-react/ssr

import {createDomain} from 'effector'
import {createGate, useGate} from 'effector-react/ssr'

const app = createDomain()

const currentRouteGate = createGate({
  domain: app,
  defaultState: 'dashboard',
})

export const Layout = ({routeName, children}) => {
  useGate(currentRouteGate, routeName)
  return (
    <>
      <h1>{routeName}</h1>
      {children}
    </>
  )
}

effector-react 21.1.0

Add support for object and array of events to useEvent. It's a shorthand for calling several useEvent at once (PR #425 by @sergeysova)

export function ExampleComponent() {
  const handlers = useEvent({emailChanged, passwordChanged})

  return (
    <div>
      <input onChange={handlers.emailChanged} />
      <input onChange={handlers.passwordChanged} />
    </div>
  )
}

export function ExampleComponent() {
  const [changeEmail, changePassword] = useEvent([
    emailChanged,
    passwordChanged,
  ])

  return (
    <div>
      <input onChange={changeEmail} />
      <input onChange={changePassword} />
    </div>
  )
}

effector 21.7.0

Add support for scopes to hydrate, to provide a way to fill additional values to existing scope (happens during SSG navigation in next.js)
Improve prepend type inference (PR #415 (thanks @doasync))

effector-vue 21.1.0

Add support for vue@next (vue 3)
useStore useVModel useGate createGate see docs

effector 21.6.0

Add support for user-defined factories in fork api. Starting from this release, application developers can use their own functions and be sure that their content will be properly serialized and hydrated by fork api. New field factories in effector/babel-plugin accepts array of module names which exports will be treated as custom factories therefore each function call will provide unique prefix for sid properties of units inside them

`json title=".babelrc" { "plugins": [ [ "effector/babel-plugin", { "factories": ["src/createEffectStatus", "~/createCommonPending"] } ] ] }


```js title="./src/createEffectStatus.js"
import {rootDomain} from './rootDomain'

export function createEffectStatus(fx) {
  const $status = rootDomain
    .createStore('init')
    .on(fx.finally, (_, {status}) => status)

  return $status
}

`js title="./src/statuses.js" import {createEffectStatus} from './createEffectStatus' import {fetchUserFx, fetchFriendsFx} from './api'

export const $fetchUserStatus = createEffectStatus(fetchUserFx) export const $fetchFriendsStatus = createEffectStatus(fetchFriendsFx)


Import `createEffectStatus` from `'./createEffectStatus'` was treated as factory function so each store created by it has its own `sid` and will be handled by serialize independently, although without `factories` they will share the same `sid`

[factories in documentation](https://effector.dev/docs/api/effector/babel-plugin#factories)

- Add user-friendly unit name in fork api error messages when given unit is not found in scope. This improves error messages in both `effector` and `effector-react`

- Add validation for `values` and `handlers` fields in `fork` and for `values` field in `hydrate`

- Add type support for `createEffect<typeof handler, Error>(handler)` to infer `Params` and `Done` types from given `handler` and provide custom `Fail` type at the same time

[createEffect and custom errors](https://effector.dev/docs/typescript/typing-effector#createeffect-and-custom-errors) in documentation

- Improve `guard` return type inference (PR [#406](https://github.com/effector/effector/pull/406) (thanks [@doasync](https://github.com/doasync)))

- Fix void params support for `createEffect(name, config)` (issue [#404](https://github.com/effector/effector/issues/404))

- Allow to use `Event<void>` in cases when only `() => void` is accepted (PR [#400](https://github.com/effector/effector/pull/400) (thanks [@doasync](https://github.com/doasync)))

- Add support for `merge` to `effector/babel-plugin`

## effector 21.5.0

- Add support for `attach({effect})` to create effect which will call `effect` with params as it is. That allow to create separate effects with shared behavior (PR [#396](https://github.com/effector/effector/pull/396) and [#397](https://github.com/effector/effector/pull/397) (thanks [@sergeysova](https://github.com/sergeysova) and [@oas89](https://github.com/oas89)))

- Add `reactSsr` option to `effector/babel-plugin` to replace imports from `effector-react` to `effector-react/ssr`. Useful for building both server-side and client-side builds from the same codebase

## effector 21.4.0

- Add support for return status to `allSettled`. When `allSettled` is called with `Effect`, it return object with `value` and `status` fields ([discussion](https://github.com/effector/effector/issues/385))

```js
import {createDomain, fork, allSettled} from 'effector'

const app = createDomain()
const fx = app.createEffect(() => 'ok')
const result = await allSettled(fx, {scope: fork(app)})
// => {status: 'done', value: 'ok'}