I'm using react context & axios interceptors to hide/show a loading spinner. While it does hide and show correctly when requests and responses are fired, my loading spinner is only showing at the start of a network request. The request fires and then goes into a 'pending' status. During the 'pending' status, the response interceptor is fired and hides the loading spinner.
How can I make sure the loading spinner stays visible during the pending requests?
I tried adding some console logs to fire when the requests, responses, and errors were returned including the count, and it showed it (for two requests) to successfully go from 0 - 1 - 2 - 1 - 0, but in the chrome devtools network tab showed as pending even though all requests were returned.
EDIT: thought I had it working after some refactor but it was a no-go. Added updated code
import React, { useReducer, useRef, useEffect, useCallback } from "react";
import { api } from "api/api";
import LoadingReducer from "reducer/LoadingReducer";
const LoadingContext = React.createContext();
export const LoadingProvider = ({ children }) => {
const [loader, dispatch] = useReducer(LoadingReducer, {
loading: false,
count: 0,
});
const loaderKeepAlive = useRef(null),
showLoader = useRef(null);
const showLoading = useCallback(() => {
dispatch({
type: "SHOW_LOADING",
});
}, [dispatch]);
const hideLoading = useCallback(() => {
loaderKeepAlive.current = setTimeout(() => {
dispatch({
type: "HIDE_LOADING",
});
}, 3000);
return clearTimeout(loaderKeepAlive.current);
}, [dispatch]);
const requestHandler = useCallback(
(request) => {
dispatch({ type: "SET_COUNT", count: 1 });
return Promise.resolve({ ...request });
},
[dispatch]
);
const errorHandler = useCallback(
(error) => {
dispatch({ type: "SET_COUNT", count: -1 });
return Promise.reject({ ...error });
},
[dispatch]
);
const successHandler = useCallback(
(response) => {
dispatch({ type: "SET_COUNT", count: -1 });
return Promise.resolve({ ...response });
},
[dispatch]
);
useEffect(() => {
if (loader.count === 0) {
hideLoading();
clearTimeout(showLoader.current);
} else {
showLoader.current = setTimeout(() => {
showLoading();
}, 1000);
}
}, [showLoader, showLoading, hideLoading, loader.count]);
useEffect(() => {
if (!api.interceptors.request.handlers[0]) {
api.interceptors.request.use(
(request) => requestHandler(request),
(error) => errorHandler(error)
);
}
if (!api.interceptors.response.handlers[0]) {
api.interceptors.response.use(
(response) => successHandler(response),
(error) => errorHandler(error)
);
}
return () => {
clearTimeout(showLoader.current);
};
}, [errorHandler, requestHandler, successHandler, showLoader]);
return (
<LoadingContext.Provider
value={{
loader,
}}
>
{children}
</LoadingContext.Provider>
);
};
export default LoadingContext;
I think a more standard approach would be to just utilize the loading state to conditionally render the Spinner and the result of the promise to remove it from the DOM (see demo below). Typically, the interceptors are used for returning the error from an API response, since axios defaults to the status error (for example, 404 - not found).
For example, a custom axios interceptor to display an API error:
import get from "lodash.get";
import axios from "axios";
const { baseURL } = process.env;
export const app = axios.create({
baseURL
});
app.interceptors.response.use(
response => response,
error => {
const err = get(error, ["response", "data", "err"]);
return Promise.reject(err || error.message);
}
);
export default app;
Demo
Code
App.js
import React, { useEffect, useCallback, useState } from "react";
import fakeApi from "./api";
import { useAppContext } from "./AppContext";
import Spinner from "./Spinner";
const App = () => {
const { isLoading, error, dispatch } = useAppContext();
const [data, setData] = useState({});
const fetchData = useCallback(async () => {
try {
// this example uses a fake api
// if you want to trigger an error, then pass a status code other than 200
const res = await fakeApi.get(200);
setData(res.data);
dispatch({ type: "loaded" });
} catch (error) {
dispatch({ type: "error", payload: error.toString() });
}
}, [dispatch]);
const reloadData = useCallback(() => {
dispatch({ type: "reset" });
fetchData();
}, [dispatch, fetchData]);
useEffect(() => {
fetchData();
// optionally reset context state on unmount
return () => {
dispatch({ type: "reset" });
};
}, [dispatch, fetchData]);
if (isLoading) return <Spinner />;
if (error) return <p style={{ color: "red" }}>{error}</p>;
return (
<div style={{ textAlign: "center" }}>
<pre
style={{
background: "#ebebeb",
margin: "0 auto 20px",
textAlign: "left",
width: 600
}}
>
<code>{JSON.stringify(data, null, 4)}</code>
</pre>
<button type="button" onClick={reloadData}>
Reload
</button>
</div>
);
};
export default App;
AppContext.js
import React, { createContext, useContext, useReducer } from "react";
const AppContext = createContext();
const initialReducerState = {
isLoading: true,
error: ""
};
const handleLoading = (state, { type, payload }) => {
switch (type) {
case "loaded":
return { isLoading: false, error: "" };
case "error":
return { isLoading: false, error: payload };
case "reset":
return initialReducerState;
default:
return state;
}
};
export const AppContextProvider = ({ children }) => {
const [state, dispatch] = useReducer(handleLoading, initialReducerState);
return (
<AppContext.Provider
value={{
...state,
dispatch
}}
>
{children}
</AppContext.Provider>
);
};
export const useAppContext = () => useContext(AppContext);
export default AppContextProvider;
Spinner.js
import React from "react";
const Spinner = () => <div className="loader">Loading...</div>;
export default Spinner;
fakeApi.js
const data = [{ id: "1", name: "Bob" }];
export const fakeApi = {
get: (status) =>
new Promise((resolve, reject) => {
setTimeout(() => {
status === 200
? resolve({ data })
: reject(new Error("Unable to locate data."));
}, 2000);
})
};
export default fakeApi;
index.js
import React from "react";
import ReactDOM from "react-dom";
import AppContextProvider from "./AppContext";
import App from "./App";
import "./styles.css";
const rootElement = document.getElementById("root");
ReactDOM.render(
<React.StrictMode>
<AppContextProvider>
<App />
</AppContextProvider>
</React.StrictMode>,
rootElement
);
Related
I'm trying to check if my store is onboarded or not. for that, I'm making an API call through the redux to check it in the BE and if it's true I'll redirect it to the dashboard. I'm able to get the data successfully from BE, and on success checkIsStoreOnboardedSuccess() is called but in the reducer, the state is not updated with the CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_SUCCESS state in the reducer.
action.js
import * as actionTypes from './index';
import API from '../../api';
export const clearCheckIsStoreOnboarded = () => {
return {
type: actionTypes.CLEAR_CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING,
};
};
export const checkIsStoreOnboarded = (payload) => {
return (dispatch) => {
dispatch(checkIsStoreOnboardedInitiate());
API.getAccountSettings(payload)
.then((response) => {
checkIsStoreOnboardedSuccess(response.data);
})
.catch((err) => {
checkIsStoreOnboardedFailure(err);
});
};
};
const checkIsStoreOnboardedInitiate = () => {
return {
type: actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_START,
};
};
const checkIsStoreOnboardedSuccess = (data) => {
return {
type: actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_SUCCESS,
data: data,
};
};
const checkIsStoreOnboardedFailure = (err) => {
return {
type: actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_FAIL,
data: err,
};
};
reducer.js
import * as actionTypes from '../actions';
const initialState = {
isLoading: true,
isError: false,
isDone: false,
data: [],
error: null,
};
const clearCheckIsStoreOnboarded = () => {
return initialState;
};
const checkIsStoreOnboardedStart = (state) => {
return { ...state, isLoading: true, error: null, isError: false };
};
const checkIsStoreOnboardedSuccess = (state, action) => {
return { ...state, data: action.data, isDone: true, isLoading: false };
};
const checkIsStoreOnboardedFailure = (state, action) => {
return { ...state, error: action.data, isLoading: false, isError: true };
};
const reducer = (state = initialState, action) => {
switch (action.type) {
case actionTypes.CLEAR_CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING:
return clearCheckIsStoreOnboarded();
case actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_START:
return checkIsStoreOnboardedStart(state);
case actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_SUCCESS:
return checkIsStoreOnboardedSuccess(state, action);
case actionTypes.CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_FAIL:
return checkIsStoreOnboardedFailure(state, action);
default:
return state;
}
};
export default reducer;
actionTypes.js
export const CLEAR_CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING = 'CLEAR_CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING';
export const CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_START = 'CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_START';
export const CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_SUCCESS = 'CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_SUCCESS';
export const CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_FAIL = 'CHECK_IS_STORE_ONBOARDED_FOR_ONBOARDING_FAIL';
onboard.js
import React, { useState, useEffect } from 'react';
import { withCookies } from 'react-cookie';
import { Redirect } from 'react-router-dom';
import { connect } from 'react-redux';
import Crew from './Crew';
import Service from './Services';
import Address from './Address';
import { useStyles } from './css/index.css';
import Header from './header';
import Stepper from './stepper';
import { getStoreID } from '../../../utils';
import {
clearCheckIsStoreOnboarded,
checkIsStoreOnboarded,
} from '../../../store/actions/check-is-store-onboarded-for-onboarding'
import Loader from '../../../components/CircularProgressLoader';
const OnboardScreen = ({
cookies,
clearCheckIsStoreOnboarded,
checkIsStoreOnboarded,
checkIsStoreOnboardedData,
}) => {
const [step, setStep] = useState(0);
// eslint-disable-next-line no-unused-vars
const [width, isDesktop] = useWindowWitdh();
const classes = useStyles(isDesktop);
const store_id = getStoreID(cookies);
useEffect(() => {
checkIsStoreOnboarded({
store_id,
});
}, []);
useEffect(() => () => clearCheckIsStoreOnboarded(), []);
if(checkIsStoreOnboarded.isDone){
<Redirect to='/dashboard'>
}
const updateStep = () => {
const updatedStep = step + 1;
setStep(updatedStep);
};
const onboardingScreenToRender = () => {
switch (step) {
case 0:
return (
<Crew />
);
case 1:
return (
<Service />
);
case 2:
return <Address />;
}
};
return (
<div className={classes.container}>
<Header isDesktop={isDesktop} />
<div className={classes.contentOfContainer}>
<div className={classes.titleHeader}>
Onboarding
</div>
<Stepper stepNumber={step} setStepNumber={setStep} />
{checkIsStoreOnboardedData.isLoading && <Loader />}
</div>
</div>
// <OnboardLoader />
);
};
const mapStateToProps = (state, ownProps) => {
return {
...ownProps,
checkIsStoreOnboardedData: state.checkIsStoreOnboardedForOnboardingReducer
};
};
const mapDispatchToProps = (dispatch) => {
return {
checkIsStoreOnboarded: (payload) => dispatch(checkIsStoreOnboarded(payload)),
clearCheckIsStoreOnboarded: () => dispatch(clearCheckIsStoreOnboarded()),
};
};
export default connect(
mapStateToProps,
mapDispatchToProps,
)(withCookies(OnboardScreen));
You need to dispatch your actions:
export const checkIsStoreOnboarded = (payload) => {
return (dispatch) => {
dispatch(checkIsStoreOnboardedInitiate());
API.getAccountSettings(payload)
.then((response) => {
// here
dispatch(checkIsStoreOnboardedSuccess(response.data));
})
.catch((err) => {
// and here
dispatch(checkIsStoreOnboardedFailure(err)(;
});
};
};
That said: you are writing a very outdated style of Redux here - in modern Redux, all of that would probably be possible with 1/4 of the code. If you are just learning Redux, you are probably following a very outdated tutorial. Modern Redux does not require you to write action type strings or action creators and your reducers can contain mutable logic. Also, it does not use connect unless you are working with legacy class components (which you don't seem to be doing).
I really recommend you to read the official Redux tutorial at https://redux.js.org/tutorials/essentials/part-1-overview-concepts
Hllo Guys, I'm having a bit trouble with testing my component
The problem is that I would like to test my React Native Component that uses saga to fetch data from server.
The Problem is that I do know what I'm supposed to do, I think I should mock my API calls in my test file but I do not know how :/
The component file is really simple, when mounted it dispatches action to fetch list on vehicles, and then it shows them in UI. And until that is fetched it shows loading text
Bellow are my current setup of components & test file.
Here is a screen component that fetches initial data on screen load
Screen Component
import React, { useContext, useEffect, useState } from 'react';
import { Platform, FlatList, View, ActivityIndicator, Text } from 'react-native';
import PropTypes from 'prop-types';
import { useDispatch, useSelector } from 'react-redux';
import { vehiclesActions } from '_store/vehicles';
export const MainScreen = ({ navigation }) => {
/**
* Redux selectors and dispatch
*/
const {
loading = true,
vehicles = [],
loadMore = false
} = useSelector((state) => state.vehicles);
/**
* Initial effect, fetches all vehicles
*/
useEffect(() => {
dispatch(
vehiclesActions.vehicleGet({
page: 1,
})
);
}, []);
const renderCard = () => {
return (<View><Text>Test</Text></View>)
}
if (loading) {
return (<View><Text>App Loading </Text></View>
}
return (
<View style={styles.wrapper}>
<View
style={
Platform.OS === 'ios' ? { marginTop: 30 } : { marginTop: 0, flex: 1 }
}
>
{!loading && (
<View style={Platform.OS === 'ios' ? {} : { flex: 1 }}>
<FlatList
testID={'flat-list'}
data={vehicles}
renderItem={renderCard}
/>
</View>
)}
</View>
</View>
);
};
MainScreen.propTypes = {
navigation: PropTypes.object
};
export default MainScreen;
My Vehicles Saga:
const api = {
vehicles: {
getVehicles: (page) => {
return api.get(`/vehicles/list?page=${page}`, {});
},
}
function* getVehicles(action) {
try {
const { page } = action.payload;
const { data } = yield call(api.vehicles.getVehicles, page);
yield put({ type: vehiclesConstants.VEHICLE_GET_SUCCESS, payload: data });
} catch (err) {
yield call(errorHandler, err);
yield put({ type: vehiclesConstants.VEHICLE_GET_FAIL });
}
}
export function* vehiclesSaga() {
yield takeLatest(vehiclesConstants.VEHICLE_GET_REQUEST, getVehicles);
}
Actions:
export const vehiclesActions = {
vehicleGet: payload => ({ type: vehiclesConstants.VEHICLE_GET_REQUEST, payload }),
vehicleGetSuccess: payload => ({ type: vehiclesConstants.VEHICLE_GET_SUCCESS, payload }),
vehicleGetFail: error => ({ type: vehiclesConstants.VEHICLE_GET_FAIL, error }),
}
Reducer
import { vehiclesConstants } from "./constants";
const initialState = {
vehicles: [],
loading: true,
};
export const vehiclesReducer = (state = initialState, action) => {
switch (action.type) {
case vehiclesConstants.VEHICLE_GET_REQUEST:
return {
...state,
loading: true,
};
case vehiclesConstants.VEHICLE_GET_SUCCESS:
return {
...state,
loading: false,
vehicles: action.payload,
};
}
}
My Test File
import 'react-native';
import React from 'react';
import {cleanup, render, fireEvent} from '#testing-library/react-native';
import AppScreen from '../../../../src/screens/App/index';
import {Provider} from 'react-redux';
import {store} from '../../../../src/store/configureStore';
describe('App List Component', () => {
beforeEach(() => jest.useFakeTimers());
afterEach(cleanup);
it('should render vehicle list page title', async () => {
const navigation = {
setParams: () => {},
navigate: jest.fn(),
};
const route = {
}
const component = (
<Provider store={store}>
<AppScreen route={route} navigation={navigation} />
</Provider>);
const {getByText, getByTestId} = render(component);
const pageTitle = await getByText('App Loading'); // this works fine
expect(pageTitle).toBeDefined();
});
it('should navigate to add vehicle', async () => {
const navigation = {
setParams: () => {},
navigate: jest.fn(),
};
const route = {
}
const component = (
<Provider store={store}>
<AppScreen route={route} navigation={navigation} />
</Provider>);
const {getByText, getByTestId} = render(component);
const flatList = await getByTestId('flat-list');// this throws error since flat list is still not shown, and loading is showing instead
});
Like I see above I cannot find element with testId flat-list, since component AppScreen it always show loading text, is there any way I could mock that API call and make this to work ?
Jest allows you to mock any module using jest.mock.
You have to write an alternative to axios.get like this
const vehiclesData = [
// ... put default data here
]
const delay = (ms, value) =>
new Promise(res => setTimeout(() => res(value), ms))
const mockAxiosGet = async (path) => {
let result = null
if (path.includes('vehicles/list') {
const query = new URLSearchParams(path.replace(/^[^?]+\?/, ''))
const page = + query.get('page')
const pageSize = 10
const offset = (page - 1)*pageSize
result = vehiclesData.slice(offset, offset + pageSize)
}
return delay(
// simulate 100-500ms latency
Math.floor(100 + Math.random()*400),
{ data: result }
)
}
Then modify the test file as
import 'react-native';
import React from 'react';
import {cleanup, render, fireEvent} from '#testing-library/react-native';
import axios from 'axios'
// enable jest mock on 'axios' module
jest.mock('axios')
import AppScreen from '../../../../src/screens/App/index';
import {Provider} from 'react-redux';
import {store} from '../../../../src/store/configureStore';
describe('App List Component', () => {
before(() => {
// mock axios implementation
axios.get.mockImplementation(mockAxiosGet)
})
beforeEach(() => jest.useFakeTimers());
afterEach(cleanup);
it('should render vehicle list page title', async () => {
const navigation = {
setParams: () => {},
navigate: jest.fn(),
};
const route = {
}
const component = (
<Provider store={store}>
<AppScreen route={route} navigation={navigation} />
</Provider>);
const {getByText, getByTestId} = render(component);
const pageTitle = await getByText('App Loading'); // this works fine
expect(pageTitle).toBeDefined();
});
it('should navigate to add vehicle', async () => {
const navigation = {
setParams: () => {},
navigate: jest.fn(),
};
const route = {
}
const component = (
<Provider store={store}>
<AppScreen route={route} navigation={navigation} />
</Provider>);
const {getByText, getByTestId} = render(component);
const flatList = await getByTestId('flat-list');// this throws error since flat list is still not shown, and loading is showing instead
});
For your use case, read more at Mocking Implementations
Am new to redux.
I am working now on an app that shows a list of soccer leagues in each country.
Firstly, I am fetching a countries list. Afterwards, I am using the country name to loop through all countries to get the soccer leagues. Not every country has a soccer league, so I get some null as response, which I filter out. Then I click on a league and I am redirected to a league page. Now comes the tricky part. When I click "back", I go to my main page, but the whole api call process gets fired again. Why? How to prevent it? how to only use the data, that I fetched ones, and only use it as I need to.
If I would guess, than the mistake is somewhere in the reducer. I try there to cache the fetched api call in an object (data: { ...state.data, ...}), but am not sure, if I do this correctly.
The second place, where I could do a m istake is the useEffect. But of course anything else is also possible.
Please help!
Here is my code:
App.js
I use react-router-dom to move between the conatiners:
import React from 'react';
import {Switch, Route, NavLink, Redirect} from "react-router-dom";
import SignedIn from '../signedIn/signedIn';
import SignedOut from '../signedOut/signedOut';
//Components/Containers
import AllLeagues from '../allLeagues/allLeagues/allLeagues';
import League from "../allLeagues/league/league";
const App = () => {
return (
<div className="App">
<nav>
<NavLink to={"/"}>SEARCH</NavLink>
</nav>
<Switch>
<Route path={"/"} exact component={AllLeagues} />
<Route path={"/allLeagues/:league"} exact component={League} />
<Route path={"/signedin"} exact component={SignedIn} />
<Route path={"/signedout"} exact component={SignedOut} />
<Redirect to={"/"} />
</Switch>
</div>
);
}
export default App;
Here is my Page, where I make the api calls to get the countries and the soccer leagues:
allLeagues.js
import React, { useEffect } from "react";
import { useSelector, useDispatch } from "react-redux";
import {Link} from "react-router-dom";
import _ from "lodash";
import shortid from "shortid";
import { allLeagues } from "../../../actions/leagues/allLeagues/allLeagues";
import { allCountries } from "../../../actions/allCountries/allCountries";
//the api provides 255 country names.
const ALL_COUNTRIES_LENGTH = 254;
const AllLeagues = () => {
const dispatch = useDispatch();
const selectAllCountries = useSelector(state => state.allCountries);
const selectAllLeagues = useSelector(state => state.allLeagues);
useEffect(() => {
dispatch(allCountries());
}, [dispatch]);
useEffect(() => {
if(!_.isEmpty(selectAllCountries.data)) {
selectAllCountries.data.countries.map(el => dispatch(allLeagues(el.name_en)));
}
}, [dispatch, selectAllCountries.data]);
let allCountriesArr = [];
let allLeaguesFiltered = [];
let getAllLeagues = [];
allCountriesArr = (Object.values(selectAllLeagues.data));
console.log(Object.values(selectAllLeagues.data));
if(allCountriesArr.length > ALL_COUNTRIES_LENGTH) {
allLeaguesFiltered = allCountriesArr.flat().filter(el => el !== null);
getAllLeagues = allLeaguesFiltered.flat();
}
let getAllZeroDivisionLeagues = [];
let getAllFirstDivisionLeagues = [];
let getAllSecondDivisionLeagues = [];
let getAllThirdDivisionLeagues = [];
if(!_.isEmpty(getAllLeagues)) {
getAllZeroDivisionLeagues = getAllLeagues.filter(el => el.strDivision === "0");
getAllFirstDivisionLeagues = getAllLeagues.filter(el => el.strDivision === "1");
getAllSecondDivisionLeagues = getAllLeagues.filter(el => el.strDivision === "2");
getAllThirdDivisionLeagues = getAllLeagues.filter(el => el.strDivision === "3");
}
const showData = () => {
if(!_.isEmpty(selectAllLeagues.data)) {
return(
<div>
Most Favorited Leagues:
<br/>
{getAllZeroDivisionLeagues.map(el => {
return (
<div key={shortid.generate()}>
<p>{el.strLeague}</p>
<Link to={`/allLeagues/${el.strLeague}`}>View</Link>
</div>
)}
)}
<br/>
<br/>
First Leagues:
<br/>
{getAllFirstDivisionLeagues.map(el => {
return (
<div key={shortid.generate()}>
<p>{el.strLeague}</p>
<Link to={`/allLeagues/${el.strLeague}`}>View</Link>
</div>
)}
)}
<br/>
<br/>
Second Leagues:
<br/>
{getAllSecondDivisionLeagues.map(el => {
return (
<div key={shortid.generate()}>
<p>{el.strLeague}</p>
<Link to={`/allLeagues/${el.strLeague}`}>View</Link>
</div>
)}
)}
<br/>
<br/>
Third Leagues:
<br/>
{getAllThirdDivisionLeagues.map(el => {
return (
<div key={shortid.generate()}>
<p>{el.strLeague}</p>
<Link to={`/allLeagues/${el.strLeague}`}>View</Link>
</div>
)}
)}
</div>
)
}
if (selectAllLeagues.loading) {
return <p>loading...</p>
}
if (selectAllLeagues.errorMsg !== "") {
return <p>{selectAllLeagues.errorMsg}</p>
}
return <p>Loading...</p>;
}
return (
<div>
<br/>
<br/>
All Leagues:
<br />
<br />
{showData()}
</div>
)
}
export default AllLeagues;
The both action files:
allCountries.js
import { GET_ALL_COUNTRIES_LOADING, GET_ALL_COUNTRIES_SUCCESS, GET_ALL_COUNTRIES_FAIL } from "../index";
import theSportsDB from "../../apis/theSportsDB";
export const allCountries = () => async (dispatch) => {
try {
dispatch ({
type: GET_ALL_COUNTRIES_LOADING
})
const response = await theSportsDB.get("all_countries.php");
dispatch ({
type: GET_ALL_COUNTRIES_SUCCESS,
payload: response.data
})
} catch (e) {
dispatch ({
type: GET_ALL_COUNTRIES_FAIL
})
}
}
and allCountriesReducer:
import {GET_ALL_COUNTRIES_LOADING, GET_ALL_COUNTRIES_SUCCESS, GET_ALL_COUNTRIES_FAIL} from "../../actions/index";
const DefaultState = {
loading: false,
data: [],
errorMsg: ""
};
const AllCountriesReducer = (state = DefaultState, action) => {
switch (action.type){
case GET_ALL_COUNTRIES_LOADING:
return {
...state,
loading: true,
errorMsg: ""
};
case GET_ALL_COUNTRIES_SUCCESS:
return {
...state,
loading: false,
data: {
...state.data,
countries: action.payload.countries
},
errorMsg: ""
};
case GET_ALL_COUNTRIES_FAIL:
return {
...state,
loading: false,
errorMsg: "unable to get all the Countries"
};
default:
return state;
}
}
export default AllCountriesReducer;
Now the files, with which I fetch the all the leagues (with the country name, that I got from allCountries):
import { GET_ALL_LEAGUES_LOADING, GET_ALL_LEAGUES_SUCCESS, GET_ALL_LEAGUES_FAIL } from "../../index";
import theSportsDB from "../../../apis/theSportsDB";
export const allLeagues = (country) => async (dispatch) => {
try {
dispatch ({
type: GET_ALL_LEAGUES_LOADING
})
const response = await theSportsDB.get(`search_all_leagues.php?c=${country}&s=Soccer`);
dispatch ({
type: GET_ALL_LEAGUES_SUCCESS,
payload: response.data,
countryName: country
})
} catch (e) {
dispatch ({
type: GET_ALL_LEAGUES_FAIL
})
}
}
and the reducer,
allLeaguesReducer.js
import {GET_ALL_LEAGUES_LOADING, GET_ALL_LEAGUES_SUCCESS, GET_ALL_LEAGUES_FAIL} from "../../../actions/index";
const DefaultState = {
loading: false,
data: {},
errorMsg: ""
};
const AllLeaguesReducer = (state = DefaultState, action) => {
switch (action.type){
case GET_ALL_LEAGUES_LOADING:
return {
...state,
loading: true,
errorMsg: ""
};
case GET_ALL_LEAGUES_SUCCESS:
return {
...state,
loading: false,
data:{
...state.data,
[action.countryName]: action.payload.countrys
},
errorMsg: ""
};
case GET_ALL_LEAGUES_FAIL:
return {
...state,
loading: false,
errorMsg: "unable to get all the leagues"
};
default:
return state;
}
}
export default AllLeaguesReducer;
Also the leagues page itself:
import React, { useEffect } from "react";
import { useSelector, useDispatch } from "react-redux";
import {Link} from "react-router-dom";
import _ from "lodash";
import shortid from "shortid";
import { getLeague } from "../../../actions/leagues/league/getLeague";
const League = (props) => {
const leagueName = props.match.params.league;
const dispatch = useDispatch();
const selectLeague = useSelector(state => state.league);
useEffect (() => {
dispatch(getLeague(leagueName));
}, [dispatch, leagueName]);
const showLeague = () => {
if(!_.isEmpty(selectLeague.data)) {
return selectLeague.data.teams.map(el => {
return (
<div key={shortid.generate()}>
{el.strTeam}
</div>
)
})
}
if(selectLeague.loading) {
return <p>loading...</p>
}
if(selectLeague.errorMsg !== "") {
return <p>{selectLeague.errorMsg}</p>
}
return <p>Unable to get the league data</p>
}
return (
<div>
<p>{leagueName}</p>
{showLeague()}
<Link to={"/"}>Back</Link>
</div>
)
}
export default League;
its action file:
import { GET_LEAGUE_LOADING, GET_LEAGUE_SUCCESS, GET_LEAGUE_FAIL } from "../../index";
import theSportsDB from "../../../apis/theSportsDB";
export const getLeague = (league) => async (dispatch) => {
try {
dispatch ({
type: GET_LEAGUE_LOADING
})
const response = await theSportsDB.get(`search_all_teams.php?l=${league}`);
dispatch ({
type: GET_LEAGUE_SUCCESS,
payload: response.data,
// leagueName: league
})
} catch (e) {
dispatch ({
type: GET_LEAGUE_FAIL
})
}
}
and the reducer:
import { GET_LEAGUE_LOADING, GET_LEAGUE_SUCCESS, GET_LEAGUE_FAIL } from "../../../actions/index";
const DefaultState = {
loading: false,
data: {},
errorMsg: ""
};
const LeagueReducer = (state = DefaultState, action) => {
switch (action.type) {
case GET_LEAGUE_LOADING:
return {
...state,
loading: true,
errorMsg: ""
};
case GET_LEAGUE_SUCCESS:
return {
...state,
loading: false,
data: action.payload,
errorMsg: ""
};
case GET_LEAGUE_FAIL:
return {
...state,
loading: false,
errorMsg: "league not found"
};
default:
return state
}
}
export default LeagueReducer;
In Redux dev Tools, when I press on back, to get again to my home page, the following is triggered (in status bar):
GET_ALL_COUNTRIES_LOADING
and after some time:
GET_ALL_LEAGUES_SUCCESS
again. So it is making an api call again.
You need to use a conditional in useEffect so that it doesn't run each time you load the page.
Try this:
useEffect(() => {
if (selectAllCountries.data.length < 1) {
disptch(getCountries());
}
})
I want to get 20 posts by scroll down each time how can i do? my project have big Data and I use redux for get data, can I get data step by step? for example get 20 posts for first time and when a user scroll down load the next 20 posts.
I use React Hooks for develop
my posts component source is:
import PropTypes from 'prop-types';
import { connect } from 'react-redux';
import Spinner from '../layout/Spinner';
import PostItem from './PostItem';
import { getPosts } from '../../actions/post';
const Posts = ({ getPosts, post: { posts, loading } }) => {
useEffect(() => {
getPosts();
}, [getPosts]);
return loading ? <Spinner /> : (
{posts.map(post => (
<PostItem key={post._id} post={post} />
))}
)
}
Posts.propTypes = {
getPosts: PropTypes.func.isRequired,
post: PropTypes.object.isRequired
}
const mapStateToProps = state => ({
post: state.post
});
export default connect(mapStateToProps, { getPosts })(Posts)
my action code is:
import { setAlert } from './alert';
import {
GET_POSTS,
POST_ERROR
} from "../actions/types";
// Get Posts
export const getPosts = () => async dispatch => {
try {
const res = await axios.get('/api/ads');
dispatch({
type: GET_POSTS,
payload: res.data
});
} catch (err) {
dispatch({
type: POST_ERROR,
payload: { msg: err.response.satusText, status: err.response.satus }
});
}
}```
///////////////////////////////
///////////////AND REDUCER IS :
import {
GET_POSTS,
POST_ERROR
} from '../actions/types';
const initialState = {
posts: [],
loading: true,
error: {}
};
export default function (state = initialState, action) {
const { type, payload } = action;
switch (type) {
case GET_POSTS:
return {
...state,
posts: payload,
loading: false
}
case POST_ERROR:
return {
...state,
error: payload,
loading: false
}
default:
return state;
}
}
You can use react-infinite-scroller library. I've tried to change your Posts method, so maybe it would be useful.but as mentioned in comments you should add pagination to your API.
const Posts = ({ getPosts, post: { posts, loading } }) => {
useEffect(() => {
getPosts();
}, [getPosts]);
const itemsPerPage = 20;
const [hasMoreItems, sethasMoreItems] = useState(true);
const [records, setrecords] = useState(itemsPerPage);
const showItems=(posts)=> {
var items = [];
for (var i = 0; i < records; i++) {
items.push( <PostItem key={posts[i]._id} post={posts[i]} />);
}
return items;
}
const loadMore=()=> {
if (records === posts.length) {
sethasMoreItems(false);
} else {
setTimeout(() => {
setrecords(records + itemsPerPage);
}, 2000);
}
}
return <InfiniteScroll
loadMore={loadMore}
hasMore={hasMoreItems}
loader={<div className="loader"> Loading... </div>}
useWindow={false}
>
{showItems()}
</InfiniteScroll>{" "}
}
Working Codesandbox sample with fake data.
My current React Native Expo app has a ScrollView that implements RefreshControl. A user pulling down the ScrollView will cause the onRefresh function to be executed, which in turns call an action creator getSpotPrices that queries an API using axios.
Problem: If there is a network problem, the axios.get() function will take very long to time out. Thus, there is a need to implement the timing out of either axios.get() or onRefresh.
How can we implement a timeout function into RefreshControl?
/src/containers/main.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { ScrollView, RefreshControl } from 'react-native';
import MyList from '../components/MyList';
import { getSpotPrices } from '../actions';
class RefreshableList extends Component {
onRefresh = () => {
this.props.getSpotPrices();
}
render() {
return (
<ScrollView
refreshControl={
<RefreshControl
refreshing={this.props.isLoading}
onRefresh={this._onRefresh}
/>
}>
<MyList />
</ScrollView>
)
}
}
const mapStateToProps = (state) => {
return {
isLoading: state.currencies.isLoading,
}
}
const mapDispatchToProps = (dispatch) => {
return {
getSpotPrices: () => dispatch(getSpotPrices()),
}
}
export default connect(mapStateToProps, mapDispatchToProps)(RefreshableList);
/src/actions/index.js
import api from "../utils/api";
import * as types from "../types";
import Axios from "axios";
const getSpotPrice = async () => {
try {
const res = await Axios.get(`https://api.coinbase.com/v2/prices/spot`);
return parseFloat(res.data.data.amount);
} catch (err) {
throw new Error(err);
}
};
export const getSpotPrices = () => async dispatch => {
try {
const price = await getSpotPrice();
dispatch({
type: types.CURRENCIES_SET,
payload: price
});
} catch (err) {
dispatch({
type: types.CURRENCIES_FAILED_FETCH,
payload: err.toString()
});
} finally {
dispatch({
type: types.CURRENCIES_IS_LOADING,
payload: false
})
}
};
/src/reducers/currencies.js
import * as types from "../types";
const initialState = {
data: {},
isLoading: false,
};
export default (state = initialState, { type, payload }) => {
switch (type) {
case types.CURRENCIES_SET:
return {
...state,
data: payload,
error: "",
isLoading: false
};
case types.CURRENCIES_FAILED_FETCH:
return {
...state,
error: payload,
isLoading: false
};
case types.CURRENCIES_IS_LOADING:
return {
isLoading: payload
}
default:
return state;
}
};
Check if user is connected internet or not using the react-native-netinfo library
NetInfo.fetch().then(state => {
console.log("Connection type", state.type);
console.log("Is connected?", state.isConnected);
this.setState({ connected: state.isConnected });
});
// Subscribe
const unsubscribe = NetInfo.addEventListener(state => {
console.log("Connection type", state.type);
this.setState({ connected: state.isConnected });
});
// Unsubscribe
unsubscribe(); <- do this in componentwillunmount
Its generally a good practice to add a timeout, in all your api calls, in axios you can easily add a timeout option like:
await axios.get(url, { headers, timeout: 5000 })
so in your case modify the axios call as
await Axios.get(https://api.coinbase.com/v2/prices/spot, { timeout: 5000 } );
I have put timeout of 5 seconds you can modify the parameter according to your need.