如何让 watcher saga 仅在第一次调度动作模式时触发 worker saga？

Question

如何让 watcher saga 仅在第一次调度 action pattern 时触发 worker saga？

function* rootSaga() {
    yield takeEvery(CHATBOT.START, handleChatbotLoad); //I want watcher saga to trigger handleChatbotLoad only on the very first dispatch of CHATBOT.START
    yield takeEvery(CONVERSATION.ADD_QUERY, handleUserInput);
}

所以，我希望 watcher saga 仅在 CHATBOT.START 的第一次调度时触发 handleChatbotLoad。我可以在 started 这样的状态下有一个标志，并且只发送一次 CHATBOT.START 。但后来我期待一个像 takeFirst 或类似的方法。有没有这样的方法可以实现？

Answer 1

您可以call (or spawn, fork) some function in root saga, which means it'll be called only once when app started. And use take在这个函数中等待动作派发：

function* onlyVeryFirstStartWatcher() {
    const action = yield take(CHATBOT.START);
    // started, do stuff...
    yield call(handleChatbotLoad);
}

function* rootSaga() {
  yield takeEvery(CONVERSATION.ADD_QUERY, handleUserInput);
  yield call(onlyVeryFirstStartWatcher)
}

如何让 watcher saga 仅在第一次调度动作模式时触发 worker saga？

How to make the watcher saga fire a worker saga only on the first dispatch on an action pattern?

redux

redux-saga

react-redux-i18n