JSFiddle - React, Tailwind, and code Playground

HTML

<div data-bind="text: Observable, updateBinding: Observable"></div>
<div data-bind="foreach: ObservableArray, updateBinding: ObservableArray">
    <span data-bind="text: $data"></span>
</div>

JavaScript

var data = new Array();

ko.bindingHandlers['updateBinding'] = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        alert("Binding Handler (Init)");
    },
    update: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        alert("Binding Handler (Update)");
    }
};

function ViewModel() {
    var self = this;
    
    self.ObservableArray = ko.observableArray();
    self.Observable = ko.observable();
}

var viewModel = new ViewModel();

// Fires Init + Update for Observable and ObservableArray
ko.applyBindings(viewModel);

// Fires Update for Observable
viewModel.Observable(1);

// Does nothing
viewModel.ObservableArray.push('1');