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Async api fetch with redux thunk

I'm having trouble fetching a list of users from an api. I think issue might be in my mapDispatchToProps function but I'm not sure. Everything else seems fine to me. I'm new to redux and I'm kinda having a hard time wrapping my head around it so any help is appreciated
The list with the users would ideally be displayed as soon as the component mounts. I did the same thing without redux store and it was working just fine, I'm just not really sure how to integrate redux
Actions
export const startLoading = () => {
return {
type: START_LOADING
}
}
export const updateUserData = payload => {
return {
type: UPDATE_USER_DATA,
payload
}
}
export const updateUserError = payload => {
return {
type: UPDATE_USER_ERROR,
payload: payload
}
}
export function fetchUsers() {
return dispatch => {
dispatch(startLoading());
fetch('https://jsonplaceholder.typicode.com/users')
.then(res => res.json())
.then(data => {
data = data.filter(user => user.id < 4);
data.forEach(user => {
user.isGoldClient = false;
user.salary = '4000';
user.photo = userThumbnail;
})
.then(data => {
dispatch(updateUserData(data));
}).catch(error => {
dispatch(updateUserError(error));
})
});
};
};
Reducers
const initialState = {
loading: false,
users: [],
error: null
};
export function userReducer(state=initialState, action){
switch(action.type){
case START_LOADING:
return {
...state,
loading: true
}
case UPDATE_USER_DATA:
return {
...state,
loading: false,
users: action.payload,
error: null
}
case UPDATE_USER_ERROR:
return {
...state,
error: action.payload,
loading: false,
users: []
};
default:
return state;
};
};
Component
class Home extends React.Component {
constructor(props) {
super(props);
this.state = {
users: [],
usersAreDisplayed: true
};
}
componentDidMount() {
fetchUsers();
}
render(){
return (
<UserList users={this.state.users} />
)
}
}
function mapStateToProps(state){
return { users: state.users }
}
function mapDispatchToProps(dispatch){
return {
fetchUsers: payload => dispatch(updateUserData(payload)),
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Home);

Looks like you are not calling the actual fetchUsers at all.
Change the component code like this
function mapStateToProps(state){
return { users: state.users }
}
// remove this function
// function mapDispatchToProps(dispatch){
// return {
// fetchUsers: payload => dispatch(updateUserData(payload)),
// }
// }
export default connect(mapStateToProps, {fetchUsers})(Home); //<---- destructure it here. Also import the function (action)
1a. fetchUsers function needs to be accessed using this.props
componentDidMount() {
this.props.fetchUsers();
}
There is an extra then block after forEach.
Remove it.
export function fetchUsers() {
return (dispatch) => {
dispatch(startLoading());
fetch("https://jsonplaceholder.typicode.com/users")
.then((res) => res.json())
.then((data) => {
data = data.filter((user) => user.id < 4);
data.forEach((user) => {
user.isGoldClient = false;
user.salary = "4000";
user.photo = userThumbnail;
});
dispatch(updateUserData(data)); // <------ no extra .then is required
})
.catch((error) => {
dispatch(updateUserError(error));
});
};
}
Also <UserList users={this.state.users} /> needs to be <UserList users={this.props.users} /> As already mentioned by #Nsevens

You are mapping redux state into your component's props.
So you should load the users from the component's props and not it's state:
render(){
return (
<UserList users={this.props.users} />
)
}

Unable to handle state 'loading' properly in react with redux

Hey guys just moved to redux so in react what i was doing was in componentDidMount(), i was calling api and soon as i received the data i was setting loading to false (initially loading was true) to get rid of the 'react spinner',
but after using redux now in componentDidMount() i am calling my action creater which is in another and there i am receving my data so how do i manage 'loading' here ? can i somehow pass something from action creater to my component that triggers state and set loading to false ? or is there any other to do it ? How do you all manage it ?
here is my code
Home.js
class home extends Component {
UNSAFE_componentWillMount() {
this.props.verifyToken();
}
componentDidMount() {
this.props.categoryAction();
}
constructor(props) {
super(props);
this.state = {
categoriesWithTheirImages: [],
displayToggle: false,
loading: false,
};
}
renderCategory = () => {
return this.props.allCategories.map((item) => {
return (
<div
className="category_div"
key={item._id}
onClick={() => this.setState({ displayToggle: true })}
>
<img
src={item.image}
alt="miss-mistake"
className="category_image_home"
/>
<span className="category_heading_home">{item.categoryName}</span>
</div>
);
});
};
render() {
if (this.state.loading) {
return (
<div className="sweet-loading-main">
<FadeLoader
css={override}
sizeUnit={"px"}
size={50}
color={"#ff9d72"}
loading={this.state.loading}
/>
</div>
);
} else {
console.log(this.props.allCategories);
return (
<React.Fragment>
{/* <Fade left> */}
<Header />
<div className="main_content_homepage">
<p className="category_select">Please select a category</p>
<div className="category_list">{this.renderCategory()}</div>
</div>
{this.renderStoryActionDialog()}
{/* </Fade> */}
</React.Fragment>
);
}
}
}
const mapStateToProps = (state) => {
console.log(state);
const images = [family, ring, beer, feedback, academic];
let categoriesWithImages = state.getCategoryReducer.map((item, index) => {
item.image = images[index];
return item;
});
console.log(categoriesWithImages);
return { allCategories: categoriesWithImages };
};
export default connect(mapStateToProps, { verifyToken, categoryAction })(home);
and my action.js file
import { CATEGORY } from "../actionTypes";
export const categoryAction = ()=> {
return dispatch => {
fetch("http://localhost:3000/api/get_categories", {
method: "GET",
}).then(res=>res.json())
.then(response => {
console.log(response)
dispatch({ type: CATEGORY, payload: response });
})
.catch(err => console.log("Eror in adding", err));
};
};
reducer file
import { USER, CATEGORY} from "../actionTypes";
const getCategoryReducer = (state = [], action) => {
switch (action.type) {
case CATEGORY:
return action.payload;
default:
return state;
}
};
export default getCategoryReducer;

You should handle the loading state in your reducer file. At the moment, it's defined in your Component file. For e.g when you dispatch the action, it should update your loading state too. I would do something like this in reducer.
import { USER, FETCH_CATEGORY, FETCH_CATEGORY_SUCCESS, FETCH_CATEGORY_FAIL} from "../actionTypes";
const INITIAL_STATE = {
loading: false,
err: false,
data: []
}
const getCategoryReducer = (state = INITIAL_STATE, action) => {
switch (action.type) {
case FETCH_CATEGORY:
return Object.assign({}, state, {
loading: true,
data: [],
})
case FETCH_CATEGORY_SUCCESS
return Object.assign({}, state, {
loading: false,
data: action.payload,
})
case FETCH_CATEGORY_FAIL
return Object.assign({}, state, {
loading: false,
data: action.payload,
err: true
})
default:
return state;
}
};
export default getCategoryReducer;
and your action file would look something like this
import { FETCH_CATEGORY, FETCH_CATEGORY_SUCCESS, FETCH_CATEGORY_FAIL } from "../actionTypes";
export const categoryAction = ()=> {
//setting loading to true
return dispatch => {
dispatch({ type: FETCH_CATEGORY });
fetch("http://localhost:3000/api/get_categories", {
method: "GET",
}).then(res=>res.json())
.then(response => {
//setting loading to false
dispatch({ type: FETCH_CATEGORY_SUCCESS, payload: response });
})
.catch(err => console.log("Eror in adding", err); dispatch({ type: FETCH_CATEGORY_FAIL, payload: err }););
};
};
You can then read the loading props in your Home.js

Redux doesn't update state

I have a problem with Redux doesn't update the state. Component gets right initial state. Action is dispatched right, data is fetched right and is accesible in action payload inside reducer. Reducer is executing, right case in switch is picked. Just new state doesn't appear in component. I have three others components where it works just fine, only this one cracks.
component
import fetchLinksPage from '../state/links/actions'
...
let Links = ({linksPageLoaded, linksPage, fetchLinksPage}) => {
useEffect( () => {
if(!linksPageLoaded) {
fetchLinksPage()
console.log(linksPage)
}
},[])
return ( ... )
}
const mapStateToProps = ({linksPageReducer}) => {
return linksPageReducer
}
const mapDispatchToProps = dispatch => {
return {
fetchLinksPage: () => dispatch(fetchLinksPage())
}
}
Links = connect(mapStateToProps, mapDispatchToProps)(Links)
actions
// action types
export const GET_LINKS_PAGE = 'GETLINKSPAGE'
export const LINKS_PAGE_LOADED = 'LINKSPAGELOADED'
export const LINKS_PAGE_ERROR = 'LINKSPAGEERROR'
// action creators
export const getLinksPage = () => {
return {
type: GET_LINKS_PAGE
}
}
export const linksPageLoaded = (data) => {
return {
type: LINKS_PAGE_LOADED,
payload: data
}
}
export const linksPageError = (error) => {
return {
type: LINKS_PAGE_ERROR,
payload: error
}
}
const fetchLinksPage = () => {
return dispatch => {
dispatch(getLinksPage())
fetch('http://portfolio.adamzajac.info/_/items/links?fields=*,logo.*.*')
.then(response => response.json())
.then(data => {
dispatch(linksPageLoaded(data.data))
})
.catch( error => {
dispatch(linksPageError(error))
})
}
}
export default fetchLinksPage
reducer
import * as actions from './actions.js'
const linksPageReducer = (state={}, action) => {
switch (action.type) {
case actions.GET_LINKS_PAGE:
return { ...state, linksPageLoading: true }
case actions.LINKS_PAGE_LOADED:
//console.log('update state')
return { ...state, linksPage: action.payload, linksPageLoading: false, linksPageLoaded: true }
case actions.LINKS_PAGE_ERROR:
return { ...state, linksPageError: action.payload, linksPageLoading: false}
default:
return { ...state, linksPageLoading: false, linksPageLoaded: false, linksPage:[], linksPageError:''}
}
}
export default linksPageReducer
store
import aboutPageReducer from './state/about/reducer'
import projectsPageReducer from './state/projects/reducer'
import skillsPageReducer from './state/skills/reducer'
import linksPageReducer from './state/links/reducer'
const rootReducer = combineReducers({
aboutPageReducer,
projectsPageReducer,
skillsPageReducer,
linksPageReducer
})
const store = createStore(
rootReducer,
applyMiddleware(thunk)
)

Warning: Failed Prop Type: The prop 'hasError' is marked as required in 'PostList', but it's value is 'undefined '

I'm fairly new to React Native and Redux and was following along with this tutorial to implement Redux with my app. When I load my PostList component, I get the following warnings for my hasError and isLoading catches as shown in the following screenshots.
I apologize for the massive amounts of source code about to be embedded in the question, I tried to cut out unnecessary code.
PostList.js (Component)
[unnecessary import statements]
import { fetchPosts, postsFetchError, postsFetchLoading } from '../actions/PostsActions';
class PostList extends Component {
static navigationOptions = ({navigation}) => {
[redacted]
}
renderPosts = ({ _id, upvotes, downvotes, message, datetime }, i) => {
[redacted]
}
componentDidMount() {
this.props.fetchData('[redacted]');
}
render() {
if (this.props.hasError) {
return (
<View style={styles.center}>
<Text>
Failed to load posts!
</Text>
</View>
)
}
if (this.props.isLoading) {
return (
<View style={styles.center}>
<ActivityIndicator animating={true} />
</View>
)
}
this.props.posts.sort(function(a,b) {
return Date.parse(b.datetime) - Date.parse(a.datetime);
})
return (
<ScrollView style={styles.container}>
{this.props.posts.map(this.renderPosts)}
</ScrollView>
)
}
}
PostList.propTypes = {
fetchData: PropTypes.func.isRequired,
posts: PropTypes.array.isRequired,
hasError: PropTypes.bool.isRequired,
isLoading: PropTypes.bool.isRequired
};
const mapStateToProps = (state) => {
return {
posts: state.posts,
hasError: state.postsFetchError,
isLoading: state.postsFetchLoading
};
};
const mapDispatchToProps = (dispatch) => {
return {
fetchData: (url) => dispatch(fetchPosts(url)),
};
};
export default connect(mapStateToProps, mapDispatchToProps)(PostList);
PostsActions.js
import axios from 'axios';
export function postsFetchError(bool) {
return {
type: 'POSTS_FETCH_ERROR',
hasError: bool
};
}
export function postsFetchLoading(bool) {
return {
type: 'POSTS_FETCH_LOADING',
isLoading: bool
};
}
export function postsFetchSuccess(posts) {
return {
type: 'POSTS_FETCH_SUCCESS',
posts
};
}
export function fetchPosts(url) {
return (dispatch) => {
dispatch(postsFetchLoading(true));
axios.get(url)
.then((response) => {
if (response.status !== 200) {
throw Error(response.statusText);
}
dispatch(postsFetchLoading(false));
return response;
})
.then((response) => dispatch(postsFetchSuccess(response.data)))
.catch(() => dispatch(postsFetchError(true)));
};
}
PostsReducers.js
export function postsError(state = false, action) {
switch (action.type) {
case 'POSTS_FETCH_ERROR':
return action.hasError;
default:
return state;
}
}
export function postsLoading(state = false, action) {
switch (action.type) {
case 'POSTS_FETCH_LOADING':
return action.isLoading;
default:
return state;
}
}
export function posts(state = [], action) {
switch (action.type) {
case 'POSTS_FETCH_SUCCESS':
return action.posts;
default:
return state;
}
}
Combining the reducers in an index and configuring the store all work fine, and I don't get warnings for actions and reducers that actually get the posts. My code matches the tutorial's examples, but I'd be shocked if someone published a tutorial that had unresolved warnings (then again this IS Javascript development so I guess anything goes). I can add further information for anyone that's curious. Thanks to anyone that helps.

Is it because:
const mapStateToProps = (state) => {
return {
posts: state.posts,
hasError: state.**postsFetchError**,
isLoading: state.**postsFetchLoading**
};
};
Does not match:
export function **postsError**(state = false, action) {
export function **postsLoading**(state = false, action)

React Native Firebase Fetching Only One Data

How can I fetch only one data and write it to Header ?
I am using firebase and react-redux.
firebase structure i try to write "organization": inovanka:
Action File Codes:
import firebase from 'firebase';
import { Actions } from 'react-native-router-flux';
import { ORGANIZATION_NAME_DATA_SUCCESS } from './types';
export const organizationName = () => {
const { currentUser } = firebase.auth();
return (dispatch) => {
firebase.database().ref(`/organizations/${currentUser.uid}`)
.on('value', snapshot => {
dispatch({ type: ORGANIZATION_NAME_DATA_SUCCESS, payload: snapshot.val() });
});
};
}
Reducer File :
import { ORGANIZATION_NAME_DATA_SUCCESS } from '../actions/types';
const INITIAL_STATE = {
};
export default (state = INITIAL_STATE, action) => {
switch (action.type) {
case ORGANIZATION_NAME_DATA_SUCCESS:
console.log(action); // data retrieved as array
return action.payload
default:
return state;
}
};
Component: (I would like to write it to this)
class HomePage extends Component {
componentWillMount() {
}
render() {
return (
<Container>
<Header>
<Text> i would like to write it here </Text>
</Header>
<Content>
</Content>
</Container>
);
}
}
const mapStateToProps = ({ homepageResponse }) => {
const organizationArray = _.map(homepageResponse, (val, uid) => {
return { ...val, uid }; //
});
return { organizationArray };
};
export default connect(mapStateToProps, { organizationName })(HomePage);

Change this:
firebase.database().ref(`/organizations/${currentUser.uid}`)
.on('value', snapshot => {
to this:
firebase.database().ref(`/organizations/${currentUser.uid}`)
.once('value', snapshot => {
using once() will read data only one time, thus fetching only one data

Solution is Here !
Action File:
export const organizationName = () => {
const { currentUser } = firebase.auth();
return (dispatch) => {
firebase.database().ref(`/organizations/${currentUser.uid}`)
.once('value', snapshot => {
_.mapValues(snapshot.val(), o => {
console.log(o);
dispatch({ type: ORGANIZATION_NAME_DATA_SUCCESS, payload: {organization: o.organization, fullname: o.fullname }});
});
});
};
}
Reducer File
const INITIAL_STATE = {
organization: '',
};
export default (state = INITIAL_STATE, action) => {
switch (action.type) {
case ORGANIZATION_NAME_DATA_SUCCESS:
console.log(action);
return {...state, organization:action.payload.organization };
default:
return state;
}
};
Component File MapToStateProps and componentWillMount
const mapStateToProps = state => {
const { organization, fullname } = state.homepageResponse;
console.log("burada" + organization);
return { organization, fullname };
};
componentWillMount(){
this.props.organizationName();
}
*Last Step Header *
render() {
return (
<Container>
<Header>
<Text> { this.props.organization } </Text>
</Header>
</Container>
}
Thank You Everyone