Create JavaScript custom event

Question

I would like to create a custom event in JavaScript.

I have a WPF application with a WebBrowser inside, and a HTML page with JavaScript.

I work with a printe

Answer 1

Requirement: ES6

let MyClass = (function () {
    let __sym = Symbol('MyClass');

    class MyClass {
        constructor() {
            this[__sym] = {};
        }
        on(event, callback) {
            this[__sym][event] = { callback: callback }
        }
        getError() {
            let event = this[__sym].error;

            if (event && event.callback) {
                event.callback('some parameter');
            }
        }
    }

    return MyClass;
}());

let myClass = new MyClass();

myClass.on('error', function (e) {
    console.log('error:', e);
});

console.log('before getting error:');

myClass.getError();