react-native-network-component

What's the point ?

This class allows you to easily fire your data fetching method when the user's network is back online or when he's resuming the app, making it easy to refresh the data or to download it as soon as possible.

Handling a disturbed and changing network is primordial for the user's experience.

How to use

The first step is to extend your component class with this one instead of React's Component one.

You also need to call super.componentDidMount() and super.componentWillUnmount() in these lifecycle methods if you're already implementing them. If you don't, skip this step.

This class will provide you with the handleNetwork() method that you should use to attach online/offline listener when you want to. A good practice would be to use it when you couldn't fetch the data.

That's about it, here's an example :

import React, { PropTypes } from 'react';
import NetworkComponent from 'react-native-network-component';
import { fetchAPI } from 'cpacollecte/src/services';
 
// Don't forget to extend with NetworkComponent
export default class Article extends NetworkComponent {
 
    constructor (props) {
        super(props);
        // In this example, 1 = loading, 2 = ok, 3 = error
        this.state = {
            status: 1
        };
    }
 
    componentDidMount () {
        // I'm already implementing componentDidMount in this class,
        // so I need to call the one from NetworkContainer
        super.componentDidMount();
        this.fetchData();
    }
 
    // My method responsible for fetching data
    async fetchData () {
        const { _id } = this.props;
 
        try {
            // Display the loader again
            if (!this.state.status !== 1) {
                this.setState({ status: 1 });
            }
            const data = await fetchAPI('articles', { params: { _id } });
            if (data) {
                this.setState({ data, status: 2 });
            } else {
                this.onError();
            }
        } catch (err) {
            console.warn(err);
            this.onError();
        }
    }
 
    onError () {
        this.setState({ status: 3 });
        // I'm firing handleNetwork only when the data couldn't be
        // fetched to avoid attaching an useless eventListener
        this.handleNetwork();
    }
 
    // and all the rendering stuff...
}

In summary, if the data couldn't be fetched when the component has been mounted, the onError and more importantly the handleNetwork methods will be fired. This way, when the user is back online, fetchData will be fired again.

In addition, resuming the app from the background will also fire fetchData, but this is customizable.

Options

This class has three options, here's how you can change them :

    constructor (props) {
        super(props, { fetchFunc: 'myFetchingMethod', handleAppState: false });
    }

Option	Description	Type	Default
fetchFunc	The name of the method that needs to be fired	string	fetchData
handleAppState	Fire the method when resuming the app	bool	true
onResumeDelay	Delay (in ms) that the apps needs to stay in background to trigger fetchFunc when resuming	number	1000 * 60 * 5 (5')

Some notes

The networking and data handling part can be extremely different from one app to the other. This little class is designed to match our needs, so it might lack features to integrate it in specific situations.

Feel free to open an issue and submit a PR to extend its functionalities.