bindings.js

(function() {
    var controllers = {};
    var addController = function (name, constructor) {
        //Store controller constructor
        controllers[name] = {
            factory: constructor,
            instances: []
        };

        //Look for elements using the controller
        var element = document.querySelector('[ng-controller=' + name + ']');
        if (!element) {
            return;
        }

        // Crate a new instance and save it
        var ctrl = new controllers[name].factory();
        controllers[name].instances.push(ctrl);

        // Get elements bound to properties
        var bindings = {};
        Array.prototype.slice.call(element.querySelectorAll('[ng-bind]')).map(function (element){
            var boundValue = element.getAttribute('ng-bind');

            if (!bindings[boundValue]) {
                bindings[boundValue] = {
                    boundValue: boundValue,
                    elements: []
                }
            }

            bindings[boundValue].elements.push(element);
        });

        // Update DOM element bound when controller property is set
        var proxy = new Proxy (ctrl, {
            set: function (target, prop, value) {
                var bind = bindings[prop];
                if (bind) {
                    bind.elements.forEach(function (element){
                        element.value = value;
                        element.setAttribute('value', value);
                    });
                }
                return Reflect.set(target, prop, value);
            }
        });

        // Listen DOM element update to set the controller property
        Object.keys(bindings).forEach(function (boundValue){
            var bind = bindings[boundValue];
            bind.elements.forEach(function (element){
                element.addEventListener('input', function (event){
                    proxy[bind.boundValue] = event.target.value;
                });
            })
        });

        // Fill proxy with ctrl properties
        // and return proxy, not the ctrl!
        Object.assign(proxy, ctrl);
        return proxy;
    }

    // Export framework in window 
    this.angular = {
        controller: addController
    }
})();