Ghost/ghost/members-auth-pages/components/MembersProvider.js

import { Component } from 'preact';

const layer0 = require('../layer0');

export default class MembersProvider extends Component {
    constructor() {
        super();
        this.setGatewayFrame = gatewayFrame => this.gatewayFrame = gatewayFrame;
        this.gateway = null;
    }

    getChildContext() {
        return {
            members: {
                createSubscription: this.createMethod('createSubscription'),
                signin: this.createMethod('signin'),
                signup: this.createMethod('signup'),
                requestPasswordReset: this.createMethod('requestPasswordReset'),
                resetPassword: this.createMethod('resetPassword')
            }
        };
    }

    render({apiUrl, children}) {
        const src = `${apiUrl}/members/gateway`;
        return (
            <div>
                { children }
                <iframe src={src} ref={this.setGatewayFrame} id="members-gateway" style="display: none;"/>
            </div>
        );
    }

    componentDidMount() {
        const gatewayFrame = this.gatewayFrame;
        gatewayFrame.addEventListener('load', () => {
            this.gateway = layer0(gatewayFrame)
        });
    }

    createMethod(method) {
        return (options) => {
            return new Promise((resolve, reject) =>
                this.gateway.call(method, options, (err, successful) => {
                    if (err || !successful) {
                        reject(err || !successful);
                    }
                    resolve(successful);
                })
            );
        }
    }

}