react-native redux repopulate the state - react-redux

Question

That's the component in question. Before the component is mounted, it successfully dispatches an action {this.props.populateGrid()}. Everything is fine, I can see the state in the logger (basically it's a nested array of random numbers). When I press the button, it should rehydrate the state with new random numbers. Yet, I get the following error: Cannot read property 'populateGrid' of undefined.
import React, { Component, PropTypes } from 'react';
import { View, StyleSheet, Button } from 'react-native';
import Grid from './Grid';
import * as globalStyles from '../styles/global';
export default class Body extends Component {
componentWillMount() {
this.refresh();
}
refresh() {
this.props.populateGrid();
}
render() {
return (
<View style={styles.body}>
<Grid inGrid={this.props.grid} />
<Button
onPress={this.refresh}
title={'Regenerate the Grid'}
/>
</View>
);
}
}
Container:
import { bindActionCreators } from 'redux';
import { connect } from 'react-redux';
import { listNumbers, pickNumber } from '../actions/numberActions';
import { populateRow, populateGrid } from '../actions/gridActions';
import Body from '../components/Body';
const mapStateToProps = state => ({
numbers: state.numbers,
grid: state.grid
});
const mapDispatchToProps = dispatch => (
bindActionCreators({
listNumbers,
pickNumber,
populateRow,
populateGrid
}, dispatch)
);
export default connect(
mapStateToProps,
mapDispatchToProps
)(Body);
Action:
import { POPULATE_ROW, POPULATE_GRID } from './actionTypes';
import { randNumbers, randGrid } from '../utils/generators';
export const populateRow = (n) => {
return {
type: POPULATE_ROW,
payload: randNumbers(n)
};
};
export const populateGrid = () => {
return {
type: POPULATE_GRID,
payload: randGrid()
};
};
reducer:
import { POPULATE_ROW, POPULATE_GRID } from '../actions/actionTypes';
export default (state = [], action = {}) => {
switch (action.type) {
case POPULATE_ROW:
return action.payload || [];
case POPULATE_GRID:
return action.payload || [];
default:
return state;
}
};
Generators of numbers (it's the second function in this case)
export const randNumbers = (n) => {
let numbers = new Array(n);
const shuffled = [];
// fill one array with the numbers 1-10
numbers = numbers.fill(1).map((_, i) => i + 1);
// shuffle by taking a random element from one array
// and pushing it to the other array
while (numbers.length) {
const idx = numbers.length * Math.random() | 0; // floor trick
shuffled.push(numbers[idx]);
numbers.splice(idx, 1);
}
return shuffled;
};
export const randGrid = () => {
const shuffled = randNumbers(6);
const array = shuffled.map(a => {
let r = new Array(6);
r = [a, ...randNumbers(5)];
return r;
});
return array;
};

Answer 1

I think you need to bind this to your refresh method in your onClick handler, so that this is set properly when refresh executes:
<Button
onPress={this.refresh.bind(this)}
title={'Regenerate the Grid'}
/>
Hope that helps!