React-redux: Why is the state undefined in my Home component? - react-native

Question

I am having troubles with getting the state in my HomeComponent.js . Every time I try to print it, it return "undefined" .
I've tried different ways to call onPress in my Home component (e.g. onPress={this.printState()}, but none work)
This is my HomeComponent.js
//import statements
const mapStateToProps = state => {
return {
jobTitles: state.jobTitles
}
}
const mapDispatchToProps = dispatch => ({
fetchJobTitles: () => dispatch(fetchJobTitles())
});
class Home extends Component {
constructor(props) {
super(props);
this.state = {
jobInputValue: '',
addressInputValue: ''
};
}
componentDidMount() {
this.props.fetchJobTitles();
}
printState = () => {
console.log('State is: ' +
JSON.stringify(this.state.jobTitles));
}
render() {
return (
<ImageBackground style={styles.bkgImage} source={require('../assets/homepage_background.jpg')}>
//JSX goes here
<Button
title="CAUTĂ"
type="outline"
underlayColor={colors.red}
titleStyle={styles.buttonTitleStyle}
color={colors.red}
style={styles.buttonStyle}
onPress={this.printState}
/>
</ImageBackground>
);
}
}
//some styles
export default connect(mapStateToProps, mapDispatchToProps)(Home);
This is my reducer (jobTitles.js):
import * as ActionTypes from '../ActionTypes';
export const jobTitles = (state = { errMess: null,
jobTitles:[]}, action) => {
switch (action.type) {
case ActionTypes.GET_JOB_TITLES:
return {...state, errMess: null, jobTitles: action.payload};
case ActionTypes.JOB_TITLES_FAILED:
return {...state, errMess: action.payload};
default:
return state;
}
};
And this is my Action Creator:
import * as ActionTypes from './ActionTypes';
import { baseUrl } from '../shared/baseUrl';
export const fetchJobTitles = () => (dispatch) => {
return fetch(baseUrl + 'api/jobs/job_keywords')
.then(response => {
if (response.ok) {
return response;
} else {
var error = new Error('Error ' + response.status + ': ' +
response.statusText);
error.response = response;
throw error;
}
},
error => {
var errmess = new Error(error.message);
throw errmess;
})
.then(response => response.json())
.then(jobTitles => dispatch(addJobTitles(jobTitles)))
.catch(error => dispatch(jobTitlesFailed(error.message)));
};
export const jobTitlesFailed = (errmess) => ({
type: ActionTypes.JOB_TITLES_FAILED,
payload: errmess
});
export const addJobTitles = (jobTitles) => ({
type: ActionTypes.GET_JOB_TITLES,
payload: jobTitles
});
This is how the response from the API looks like:
"jobTitles": Object {
"results": Array [
"Engineer",
"Software",
"Software Architect",
"Software Consultant",
"Solution Architect",
"System Architect"
]
}
I expected the console.log() statement from the print() function in the HomeComponent.js to print the JSON response from the API, but instead it returns "undefined". Any ideas why?
Any help will be greatly appreaciated!

Answer 1

In your code :
this.state = {
jobInputValue: '',
addressInputValue: ''
};
What you try to print :
this.state.jobTitles
Of course it's undefined ! Either log this.props.jobTitles or set state jobTitles to print what you want.

Answer 2

You should use this.props.jobTitles
The mapStateToProps puts data from the redux state into the props of the component. this.state only holds the local state of the component. So jobInputValue and addressInputValue in this case. Everything from mapStateToProps and mapDispatchToProps will end up in the props. (As the name of the function indicates)