socket.js

/**
 *
 * Options:
 *
 *
 */
import { Connection } from './connection.js';

/**
 * Generate a simple random string to identify the request/response.
 * Function borrowed from: https://stackoverflow.com/a/1349426/7082336
 */
function make_id() {
    let text = "";
    let possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for( let i = 0; i < 8; i++ ) {
        text += possible.charAt( Math.floor( Math.random() * possible.length ) );
    }
    return text;
}


export class Socket extends Connection {
    constructor( options = {} ) {
        super( options );

        if( typeof( options.url ) == 'undefined' || options.url == '' ) {
            throw new Error( "Socket: missing required url" );
        }

        this.type = 'socket';

        this.is_connected = new Promise( ( resolve, reject ) => {
            this.socket = new WebSocket( options.url );
            this.socket.addEventListener( 'message', this.receive );
            this.socket.addEventListener( 'open', resolve );
            this.socket.addEventListener( 'close', reject );
            this.socket.addEventListener( 'error', this.error );
        } );
    }

    /**
     * Send data to the server, this function guarantees that the data will
     * be sent to the server as long as the connection is opened.
     *
     * data can be either a string or object, if it's an object it will be
     * flattened as JSON and returned to the server stringified.
     *
     * @param  {Object/String} data - a data packet to send to the server.
     */
    send( data ) {
        this.is_connected.then( () => {

            if( typeof( data ) !== 'object' ) {
                data = {
                    data,
                };
            }

            data.call_id = make_id();

            let send_data = JSON.stringify( data );
            this.socket.send( send_data );
        } );
    }

    /**
     * receive data from the server and process and dispatch it.
     * @return {[type]} [description]
     */
    receive( event ) {
        console.log( event );
        if( event.data ) {
        }
    }

    /**
     * error handler event
     * @param  {[type]} event [description]
     * @return {[type]}       [description]
     */
    error( event ) {

    }

    /**
     * close the socket, using a promise so you can chain events
     * on closing the socket.
     *
     * @return {Promise} - Success means the connection is now closed.
     */
    close() {
        return new Promise( ( resolve, reject ) => {
            this.socket.addEventListener( 'close', resolve );
            this.socket.close();
        } );
    }
}