JSFiddle - React, Tailwind, and code Playground

HTML

<a data-bind="confirmClick: { message: 'Are you sure?', click: someMethod }">Confirmable link</a>

JavaScript

ko.bindingHandlers.confirmClick = {
    init: function(element, valueAccessor, allBindings, viewModel) {
        var value = valueAccessor();
        var message = ko.unwrap(value.message);
        var click = value.click;
        ko.applyBindingsToNode(element, { click: function () {
            if (confirm(message))
                return click.apply(this, Array.prototype.slice.apply(arguments));
        }}, allBindings);
    }
}

ko.applyBindings({
    someMethod: function(vm) {
        alert('Some method executed')
    }
})