Question

我尝试使用redux saga进行错误处理。到目前为止，当我更改api网址时，它始终返回404错误。我组织了我的减速器和redux传奇。但我无法拿取物品这是我的减速机

const homeReducer = (state : Object = initialState, action : Object) => {

  switch (action.type) {
    case HOME.GET_MOVIES_START:
      return {
        ...state,
        ProgramsLoading: true,
        fetching: true
      };

    case HOME.GET_MOVIES_FINISH:
      return {
        ...state,
        ProgramsLoading: false,
        programs: action.programs,
        fetching: true
      };
    case HOME.GET_MOVIES_REJECTED:
      return {
        ...state,
        ProgramsLoading: false,
        fetching: false
      };
    default:
      return state;
  }

};

这是我的Redux Saga。带有axios的调用api。并在那里处理数据

function* getPrograms() {
  const { data } = yield call(axios.get, "http://localhost:3000/entries");
  const fetching = false;
  const defaultValue = {
    SeriesFilteredData: [],
    MoviesFilteredData: []
  };
  const reducerFunction = (accumulator, currentValue) => {

    if (currentValue.releaseYear < 2010) {
      return accumulator;
    }
    if (currentValue.programType === "series") {
      accumulator.SeriesFilteredData.push(currentValue);
    }
    else if (currentValue.programType === "movie") {
      accumulator.MoviesFilteredData.push(currentValue);
    }
    return accumulator;
  };
  const results = data.reduce(reducerFunction, defaultValue);

  if (results) {
    yield put(homeActions.getProgramsFinish(results));
  }
  else {
    yield put(homeActions.getProgramsRejected({ ProgramsLoading: false }));
  }

}
function* homeFlow() {
  console.log(getPrograms, "getPrograms");
  yield call(delay, 2000);
  yield call(getPrograms);
}

export default function* homeSaga() {
  yield takeEvery(HOME.GET_MOVIES_START, homeFlow);
}

如何处理任何错误？

Answer 1

将所有getPrograms函数放在try catch中，并在catch块中触发homeActions.getProgramsRejected({ ProgramsLoading: false })操作

function* getPrograms() {
    try {
        const { data } = yield call(axios.get, "http://localhost:3000/entries");

        // ... the rest of your code

        if (results) {
          yield put(homeActions.getProgramsFinish(results));
        }
        else {
          yield put(homeActions.getProgramsRejected({ ProgramsLoading: false }));
        }
    }
    catch(error) {
        yield put(homeActions.getProgramsRejected({ ProgramsLoading: false }));
    }
}

然后，您可以改进它，避免编写两个相同的yield put(homeActions.getProgramsRejected({ ProgramsLoading: false }));调用。看看

function* getPrograms() {
    try {
        const { data } = yield call(axios.get, "http://localhost:3000/entries");

        // ... the rest of your code

        if (results) {
          yield put(homeActions.getProgramsFinish(results));
        }
        else {
            throw new Error('No results');
        }
    }
    catch(error) {
        yield put(homeActions.getProgramsRejected({ ProgramsLoading: false }));
    }
}

如果axios调用失败，则catch块将执行homeActions.getProgramsRejected操作
如果它没有失败，但是没有结果（您的初始管理），它将引发新的错误，并且再次，catch块将执行homeActions.getProgramsRejected操作

让我知道它是否对您有帮助

如何使用Redux Saga处理错误

1 个答案: