React Native: Send component state to other component using Tab Navigator

Question

I have a component to add todos AddTodo which works fine and update the state with my added todos and I have a component TodoItems to display the todos in <FlatList/> . I'm using React Native Tab Navigator to switch between components but I'm not sure how to send the state this.state.todos from AddTodo component to TodoItems component.

I have been researching but couldn't find a solution in Tab Navigator but there are plenty of solutions for Stack Navigator.

---

Component AddTodo

export default class AddTodo extends Component {

    constructor(props) {
       super(props);
       this.state = {
           todoText: null,
           todos: []
       }
    }

    onAdd = () => {
        if (this.state.todoText) {
            this.state.todos.push({'todoItem': this.state.todoText});
            this.setState({todos: this.state.todos});
        }
    }

    render() {
        return(
             <View>
                  <TextInput onChangeText={(text) => {
                       this.setState({todoText: text});
                  }} />
                  <TouchableOpacity onPress={() => {
                       this.onAdd;
                  }}>
             </View>
        );
    }

}

---

Component TodoItems

export default class TodoItems extends Component {

    constructor(props) {
       super(props);
       this.state = {
           todosList: []
       }
    }

    render() {
        return(
            <View>
                  <FlatList
                      data={this.state.todosList}
                      renderItem={(item, index) => {
                          <Text>{item.todoItem}</Text>
                      }} 
                  />
            </View>
        );
    }

}

---

Component Tabs

import {TabNavigator} from 'react-navigation';
import AddTodo from "./AddTodo";
import TodoItems from "./TodoItems";

var myTabs = TabNavigator(
    {
    'AddTodo':{screen: AddTodo,},
    'TodoItems':{screen: TodoItems, },
    },
    {
    tabBarPosition: 'top',
    swipeEnabled: false,
    tabBarOptions: {
        labelStyle:{
            fontSize: 13,
            fontWeight: 'bold',

        },
        indicatorStyle: {
            borderBottomColor: '#003E7D',
            borderBottomWidth: 2,
        },
        style:{
            backgroundColor: '#F30076',
            elevation: 0,
        },
    },
});


export default myTabs;

Answer 1

Well I think you have two options:

1. You can use Redux which allows you to globalise your state objects so you can use them all over your app, but it can be rather complicated https://redux.js.org/

2. Or you can render TodoItems from within AddTodo:

    render() { return( <View> <TextInput onChangeText={(text) => { this.setState({todoText: text}); }} /> <TouchableOpacity onPress={() => { this.onAdd; }}> </View> <TodoItems data={this.state.todos} /> ); } 

Then you can access that data from within TodoItems: Hope this helps!