I am implementing a project where the data going to be shared in different components. So I decided to use redux-react for state management.
I used redux react async api call to get data from api. However I got undefined when the component mounted for the first time and returned actual data.
However, when I tried to implement some function on returned data, I got this error:
"Cannot read property of undefined"
I can see the state in redux developer tools and it has data and the logs function display action correctly. I can not understand why I am getting undefined. Here is my code:
const initialState = {
candidate: {},
companies: [],
offers: [],
moreStatehere:...
}
Reducer for the candidate
export default function profileReducer(state = initialState, action) {
switch(action.type) {
case FETCH_POSTS_FAILURE:
return Object.assign({}, state, {
didInvalidate: true
})
case REQUEST_PROFILE:
return Object.assign({}, state, {
isFetching: true,
didInvalidate: false
})
case RECEIVE_PROFILE:
return {
...state,
candidate: action.data
}
default:
return state;
}
}
root reducer
const rootReducer = combineReducers({
profiles: profileReducer
})
export default rootReducer;
create store
const composeEnhanser = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__||compose;
const loggerMiddleware = createLogger()
export default function configureStore() {
return createStore(
rootReducer,
composeEnhanser(applyMiddleware(thunkMiddleware,
loggerMiddleware))
);
}
index.js
const store = configureStore();
const app = (
<Provider store= {store}>
<BrowserRouter>
<App/>
</BrowserRouter>
</Provider>
)
ReactDOM.render(app, document.getElementById('root'));
registerServiceWorker();
action creator/api call
export function feachProfiles() {
return function (dispatch) {
dispatch(requestProfile)
return fetch(API_URL)
.then(
response => response.json(),
error => console.log('An error occurred.', error)
)
.then(json =>
dispatch(receiveProfile(json))
)
}
}
componentuse
class CandidatesList extends Component {
constructor (props){
super (props)
}
componentWillMount() {
this.props.feachProfiles();
}
handleClick() {
}
componentWillUnmount() {
}
render() {
const candidate = this.props.profiles.map(profile=>(
<div> </div>
));
return (
<div>
<ViewCandidate
/>
</div>
);
}
}
const mapStateToProps = state => {
return {
profiles: state.profiles.candidate || []
}
}
const mapDispatchToProps = (dispatch) => {
return {
feachProfiles: bindActionCreators(feachProfiles, dispatch)
}
}
export default connect(mapStateToProps, mapDispatchToProps)(CandidatesList);
action RECEIVE_PROFILE @
redux-logger.js:1 prev state {profiles: {…}}
redux-logger.js:1 action {type: "RECEIVE_PROFILE", data: {…}}
redux-logger.js:1 next state {profiles: {…}}
make sure to write this just before map function
if (this.props.profiles.length === 0) return null;
this.props.profiles should have array length of greater than 0
const candidate = this.props.profiles.map(profile=>(
<div> </div>
));
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