关于redux saga的使用

Question

本人刚学saga 望详细解答 谢谢。

export function* requestTypeList() {

  try {

    yield put(fetchTypeList());

    const typeList = yield call(request, WEXIN_ARTICLE_TYPE, 'get');

    yield put(receiveTypeList(typeList.showapi_res_body.typeList));

    yield call(store.save, 'typeList', typeList.showapi_res_body.typeList);

    const errorMessage = typeList.showapi_res_error;

    if (errorMessage && errorMessage !== '') {

      yield ToastUtil.showShort(errorMessage);

    }

  } catch (error) {

    yield put(receiveTypeList([]));

    yield ToastUtil.showShort('网络发生错误，请重试');

  }

}

export function* watchRequestTypeList() {

  while (true) {

    yield take(types.REQUEST_TYPE_LIST);//请问这个take起什么作用？监听嘛？如果是可以用takeevery替换?

    yield fork(requestTypeList);

  }

}