redux-saga takeEvery只能使用setTimeout调用

Question

I have a container that dispatches the following action:

const mapDispatchToProps = (dispatch, ownProps) => { 
    return { 
        getPageTree: (siteId) => { 
            dispatch(getPageTree(siteId)); 
        }
    }
} 

const explorer = connect(
    mapStateToProps, 
    mapDispatchToProps
)(Explorer); 

In my component (to which props are sent through the container) I've added:

componentWillMount(){ 
    setTimeout(() => this.props.getPageTree()); 
}

The saga:

function* fetchPageTree(action){ 
    try{ 
        const data = yield call(Api.fetchPageTree, action.payload.url); 
        yield put({type: 'FETCH_SUCCEEDED', data}); 
    }catch(error){ 
        yield put({type: 'FETCH_FAILED', error})
    } 
}

export function* watchFetchData(){ 
    console.log('watch'); 
    yield* takeEvery('GET_PAGETREE', fetchPageTree); 
    console.log('finish watch'); 
}

The saga watcher calls the fetchPageTree properly using takeEvery when applying setTimeout in the component, but doesn't execute fetchPageTree without.
No error gets thrown either.

Any idea about the cause?

Edit:
The index.es6 file contains the following initialization logic, but is overall standard:

const sagaMiddleware = createSagaMiddleware(); 
const store = createStore(
    appReducers, //Combined reducers 
    applyMiddleware(sagaMiddleware)
); 

render(
    <Provider store={store}>
        <App />
        </Provider>, 
    document.getElementById('zp-app')
)
sagaMiddleware.run(rootSaga); 

Answer 1

When did you call render function? If the render function is called after sagaMiddleware.run(rootSaga); , it should work wo deferred call of this.props.getPageTree .