Function takeLeading

Spawns a saga on each action dispatched to the Store that matches pattern. After spawning a task once, it blocks until spawned saga completes and then starts to listen for a pattern again.

In short, takeLeading is listening for the actions when it doesn't run a saga.

Example

In the following example, we create a basic task fetchUser. We use takeLeading to start a new fetchUser task on each dispatched USER_REQUESTED action. Since takeLeading ignores any new coming task after it's started, we ensure that if a user triggers multiple consecutive USER_REQUESTED actions rapidly, we'll only keep on running with the leading action

import { takeLeading } from redux-saga/effects

function* fetchUser(action) { ... }

function* watchLastFetchUser() { yield takeLeading('USER_REQUESTED', fetchUser) }

Notes

takeLeading is a high-level API built using take and call. Here is how the helper could be implemented using the low-level Effects

const takeLeading = (patternOrChannel, saga, ...args) => fork(function*() { while (true) { const action = yield take(patternOrChannel); yield call(saga, ...args.concat(action)); } })

Spawns a saga on each action dispatched to the Store that matches pattern. After spawning a task once, it blocks until spawned saga completes and then starts to listen for a pattern again.

In short, takeLeading is listening for the actions when it doesn't run a saga.

Example

In the following example, we create a basic task fetchUser. We use takeLeading to start a new fetchUser task on each dispatched USER_REQUESTED action. Since takeLeading ignores any new coming task after it's started, we ensure that if a user triggers multiple consecutive USER_REQUESTED actions rapidly, we'll only keep on running with the leading action

import { takeLeading } from redux-saga/effects

function* fetchUser(action) { ... }

function* watchLastFetchUser() { yield takeLeading('USER_REQUESTED', fetchUser) }

Notes

takeLeading is a high-level API built using take and call. Here is how the helper could be implemented using the low-level Effects

const takeLeading = (patternOrChannel, saga, ...args) => fork(function*() { while (true) { const action = yield take(patternOrChannel); yield call(saga, ...args.concat(action)); } })

Spawns a saga on each action dispatched to the Store that matches pattern. After spawning a task once, it blocks until spawned saga completes and then starts to listen for a pattern again.

In short, takeLeading is listening for the actions when it doesn't run a saga.

Example

In the following example, we create a basic task fetchUser. We use takeLeading to start a new fetchUser task on each dispatched USER_REQUESTED action. Since takeLeading ignores any new coming task after it's started, we ensure that if a user triggers multiple consecutive USER_REQUESTED actions rapidly, we'll only keep on running with the leading action

import { takeLeading } from redux-saga/effects

function* fetchUser(action) { ... }

function* watchLastFetchUser() { yield takeLeading('USER_REQUESTED', fetchUser) }

Notes

takeLeading is a high-level API built using take and call. Here is how the helper could be implemented using the low-level Effects

const takeLeading = (patternOrChannel, saga, ...args) => fork(function*() { while (true) { const action = yield take(patternOrChannel); yield call(saga, ...args.concat(action)); } })

Spawns a saga on each action dispatched to the Store that matches pattern. After spawning a task once, it blocks until spawned saga completes and then starts to listen for a pattern again.

In short, takeLeading is listening for the actions when it doesn't run a saga.

Example

In the following example, we create a basic task fetchUser. We use takeLeading to start a new fetchUser task on each dispatched USER_REQUESTED action. Since takeLeading ignores any new coming task after it's started, we ensure that if a user triggers multiple consecutive USER_REQUESTED actions rapidly, we'll only keep on running with the leading action

import { takeLeading } from redux-saga/effects

function* fetchUser(action) { ... }

function* watchLastFetchUser() { yield takeLeading('USER_REQUESTED', fetchUser) }

Notes

takeLeading is a high-level API built using take and call. Here is how the helper could be implemented using the low-level Effects

const takeLeading = (patternOrChannel, saga, ...args) => fork(function*() { while (true) { const action = yield take(patternOrChannel); yield call(saga, ...args.concat(action)); } })

You can also pass in a channel as argument and the behaviour is the same as takeLeading(pattern, saga, ...args).

Spawns a saga on each action dispatched to the Store that matches pattern. After spawning a task once, it blocks until spawned saga completes and then starts to listen for a pattern again.

In short, takeLeading is listening for the actions when it doesn't run a saga.

Example

In the following example, we create a basic task fetchUser. We use takeLeading to start a new fetchUser task on each dispatched USER_REQUESTED action. Since takeLeading ignores any new coming task after it's started, we ensure that if a user triggers multiple consecutive USER_REQUESTED actions rapidly, we'll only keep on running with the leading action

import { takeLeading } from redux-saga/effects

function* fetchUser(action) { ... }

function* watchLastFetchUser() { yield takeLeading('USER_REQUESTED', fetchUser) }

Notes

takeLeading is a high-level API built using take and call. Here is how the helper could be implemented using the low-level Effects

const takeLeading = (patternOrChannel, saga, ...args) => fork(function*() { while (true) { const action = yield take(patternOrChannel); yield call(saga, ...args.concat(action)); } })