Dispatching Redux Data and Get the State - react-native

Question

I stuck on Redux Implementation during developing an app using React Native and Redux. I do this for the first time and followed this example.
I've already installed Redux and React Native Navigation. I would like to save the state containing data for countries (the user picked a country and would like to keep the choice by the time when it browses to all screens).
Good. I've created a component that could be seen to all screens like this:
LinksScreen.navigationOptions = {
headerTitle: 'Links',
headerRight: <CountriesPickButton/>,
};
Next, I visualize the button and wait for a change in the component. By default, it should show primary country. Next, the user clicks on the button and it opens a modal where has a dropdown menu. For example, I show you the default fetching a country:
import { connect } from 'react-redux'
import store from '../../redux/countries'
export default class CountriesPick extends Component {
render() {.... // here is the button and modal, etc. It's work.
}
constructor(props, context) {
super(props, context);
this.state = store.getState();
store.subscribe(() => {
this.setState(store.getState());
});
this.defaultCountry(251);
}
async defaultCountry(countryId) {
return fetch(URL)
.then((response) => response.json())
.then((responseJson) => {
for (const key of Object.keys(responseJson.result)) {
// this works for current screen: this.setState({ defaultCountry: responseJson.result[key], selectedCountry: responseJson.result[key].country_id });
store.dispatch({ defaultCountry: responseJson.result[key], selectedCountry: responseJson.result[key].country_id , type: 'countries' });
}
return responseJson.result;
})
.catch((error) => {
console.error(error);
});
state = {
showModal: false,
countries: [],
selectedCountry: 0,
defaultCountry: [],
type: 'countries'
};
}
Without store.dispatch({}) I can change the state with the country but it has not to share between screens. That's because I started with Redux.
Here is the Redux code ():
import { createStore } from 'redux'
const defaultState = {
showModal: false,
countries: [],
selectedCountry: 0,
defaultCountry: [],
type: 'countries'
};
function store(state = defaultState) {
return state;
}
export default createStore(store);
Something is not like it should be. When I invoke store.dispatch({...}) it's not changing the state, it returns the default array. I guess I should use <Provider></Provider> in App.js to catch every change but first, I need to understand what I wrong?
Is it connected at all? In the example that I followed, I did not see connect(). Also, I'm not sure I'm using type properly.
Thank you in advance.

Answer 1

Problems here are the following:
Example on the link you provided is bad to say the least. Do not follow it
You said to be using react-native-navigation, but the code you provided comes from react-navigation. I suggest using the latter, especially for starters
Your createStore code is not going to work, as reducer for the store should be a function of state and action
With that being said, you should definitely see Basic Tutorial of redux with examples. You will almost never have to do store.getState() or store.dispatch() while using react with redux, as react-reduxpackage (included in the tutorial I linked) will do this for you. You will instead declare dependency between your store state and props your component receives