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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} />
)
}

redux state doesnt change

I have setup the redux store but when I try to make changes to the state using mapStateToProps and mapDispatchToProps I get always the default state. So at account.js I want to get the selected language and then add it to the redux store. I try to call it in other components but I always end up with reducers/Language.js defaultState. What I'm doing wrong?
Account.js
class Account extends React.Component {
static navigationOptions = ({ navigation }) => {};
constructor(props) {
super(props);
this.state = {
language: {
sq: true,
en: false,
selected: '',
},
};
}
changeLanguage = (selected) => {
if (this.state.sq) {
this.setState({ selected: 'sq' });
} else {
this.setState({ selected: 'en' });
}
};
render() {
const navigation = this.props.navigation;
return (
<ScrollView>
<View>
<ThemeProvider>
<TableView header={I18n.t('account.lang_label')}>
<CheckboxRow
selected={this.state.language.sq}
onPress={() => {
this.setState(state => ({
language: {
sq: !state.language.sq,
en: !state.language.en,
},
}));
this.changeLanguage();
}}
title={I18n.t('account.albanian')}
/>
<CheckboxRow
selected={this.state.language.en}
onPress={() =>
this.setState(state => ({
language: {
en: !state.language.en,
sq: !state.language.sq,
},
}))
}
title={I18n.t('account.english')}
/>
</TableView>
</ThemeProvider>
</View>
</ScrollView>
);
}
}
const mapDispatchToProps = dispatch => {
return {
changeLanguage: (selected) => { dispatch(changeLanguageEn(selected))},
};
};
const mapStateToProps = state => {
return {
language: state.language.selected,
};
};
export default withNavigation(connect(
mapStateToProps,
mapDispatchToProps
)(Account));
actions/Language.js
import {CHANGE_LANGUAGE_EN, CHANGE_LANGUAGE_AL} from "./types";
export const changeLanguageEn = (language) => {
return {
type: CHANGE_LANGUAGE_EN,
lang: language,
}
};
export const changeLanguageAl = (language) => {
return {
type: CHANGE_LANGUAGE_AL,
lang: language,
}
};
reducers/Language.js
const defaultState = {
lang: '',
};
export default function reducer(state = defaultState, action) {
switch (action.type) {
case 'CHANGE_LANGUAGE_EN':
return {...state, lang: 'en'};
case 'CHANGE_LANGUAGE_AL':
return Object.assign({}, state, {
lang: 'sq',
});
default:
return state;
}
}

In your mapStateToProps function try with state.lang directly
const mapStateToProps = state => {
return {
language: state.lang,
};
};
Hope this will work.

Not entirely sure I understand your question, but it sounds like you're trying to update the redux state with the internal state of Account? You should be able to do:
this.props.changeLanguage(this.state.language.selected)
You have a method on your component defined changeLanguage as well, perhaps you could do the line above in that method, after changing the internal state
additionally, in your changeLanguage method in your Account class, I don't think this.state.sq exists since sq is a key in the language state object. Instead it should be this.state.language.sq. You don't need to add the selected argument to this method either. Try making your changeLanguage method to look like this
changeLanguage = () => {
if (this.state.sq) {
this.setState({ language.selected: 'sq' });
} else {
this.setState({ language.selected: 'en' });
}
// dispatch your action here after updating the state
this.props.changeLanguage(this.state.language.selected)
};
Now calling this.changeLanguage(); will update your internal state, and then dispatch your changeLanguage redux action

You are accessing the selected language incorrectly. state.language.selected.
In the reducer you are adding lang property in the state, so access it with the same property name in the mapStateToProps.
const mapStateToProps = state => {
return {
language: state.language.lang,
};
};

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

How to get response value from API in action.js using React

I've read many examples about this and got no result for my problem, I want to get the values inside MySQL database by using localhost, code with PHP and return the value as JSON format e.g.
[
{"id":"7",
"name":"Sammy",
"address":"New York",
"age":"42"}
]
with this format, I can fetch the data by using this code in GetApi.js
class GetApi {
static getAllUsers() {
return fetch('http://192.168.1.199/App/show_all_data.php')
.then((response) => {
if (!response.ok) {
throw Error(response.statusText);
}
dispatch(itemsIsLoading(false));
return response;
})
.then((response) => response.json())
.then((items) => dispatch(itemsFetchDataSuccess(items)))
.catch(() => dispatch(itemsHasErrored(true)));
}
}
export default GetApi;
here's the action.js
import GetApi from '../../api/GetApi';
export function itemsHasErrored(bool: boolean) {
return {
type: "ITEMS_HAS_ERRORED",
hasErrored: bool
};
}
export function itemsIsLoading(bool: boolean) {
return {
type: "ITEMS_IS_LOADING",
isLoading: bool
};
}
export function itemsFetchDataSuccess(items: Object) {
return {
type: "ITEMS_FETCH_DATA_SUCCESS",
items
};
}
export function itemsFetchData(url: any) {
return function(dispatch) {
return GetApi.getAllUsers().then(items => {
dispatch(itemsFetchDataSuccess(items));
dispatch(itemsIsLoading(false));
}).catch(error => {
throw(error);
});
};
}
here's the reducer.js
const initialState = {
isLoading: true,
hasErrored: false,
items: []
};
export default function(state: any = initialState, action: Function) {
switch (action.type) {
case "ITEMS_HAS_ERRORED":
return { ...state, hasErrored: action.hasErrored };
case "ITEMS_IS_LOADING":
return { ...state, isLoading: action.isLoading };
case "ITEMS_FETCH_DATA_SUCCESS":
return { ...state, items: action.items };
default:
return state;
}
}
called action.js function in index.js
import { itemsFetchData } from "../../actions";
...
all codings that were not related with calling action.js
...
const navigation = this.props.navigation;
let items = this.props.items;
if (items.hasOwnProperty('item')) {
items = items.item
}
return (
<List
dataArray={this.props.items}
renderRow={(
data
) =>
<ListItem icon style={styles.listitem}>
<Left>
<Text>
{data.name}
</Text>
</Left>
<Right>
<Text>
{data.address}
</Text>
</Right>
</ListItem>}
/>
);
function bindAction(dispatch) {
return {
fetchData: url => dispatch(itemsFetchData(url))
};
}
const mapStateToProps = state => ({
items: state.homeReducer.items,
hasErrored: state.homeReducer.hasErrored,
isLoading: state.homeReducer.isLoading
});
export default connect(mapStateToProps, bindAction)(ShowData);
I got no results when I'm running the code, it's just showed the loading icon. even when I set isLoading:false, the home menu showed up without the data
I'm just trying to minimize the code inside index.js because it's too long to post that here. I will do that if necessary in the next comment.

I recommend using epics , below is an example link for you to follow.
Epic Example
You can look at the actions and data ajax calls from epic and how it connects back to the action.
Note: Axios is been used here instead of fetch api...