How to extend a JS class?

[liamcurry]

Hi there! This is probably a noob question so please feel free to close this issue.

I'm experimenting with creating React components in Rust and I'm trying to wrap my head around how this might work.

React recommends creating components with ES6 classes like so:

const ReactDOM = require('react-dom');
const React = require('react');

class Hello extends React.Component {
    constructor(props) {
        super(props);
        this.state = { name: props.name };
    }

    render() {
        return React.createElement('div', null, `Hello ${this.state.name}`);
    }

    static get defaultProps() {
        return { name: 'Mary' };
    }
}

document.addEventListener('DOMContentLoaded', function () {
    ReactDOM.render(
        React.createElement(Hello, null, null),
        document.getElementById('app')
    );
});

It's also possible to create React components with plain JS objects using the create-react-class package (although creating components this way seems to be depreciated):

const ReactDOM = require('react-dom');
const React = require('react');
const createReactClass = require('create-react-class');

const Hello = createReactClass({
    getDefaultProps: function () {
        return {
            name: 'Mary'
        };
    },
    getInitialState: function () {
        return { name: this.props.name };
    },
    render: function () {
        return React.createElement('div', null, `Hello ${this.state.name}`);
    }
});

document.addEventListener('DOMContentLoaded', function () {
    ReactDOM.render(
        React.createElement(Hello, { name: 'John' }, null),
        document.getElementById('app')
    );
});

From reading the docs it seems like this might be solved using structs and the extends attribute, but I'm pretty new to Rust and I'm having a tough time putting it all together. Are there any examples/tests/docs that could help out here? I imagine an implementation for HTML Custom Elements would require a similar solution. Thanks for your time.

[alexcrichton]

Thanks for the report! Currently this isn't supported, but we want it to be! Supporting this is tracked in #210 and I'm gonna close in favor of that.