JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://github.com/greenlaw110/knockout/raw/master/build/output/knockout-latest.js"></script>
<input type="text" data-bind="value: newAction"></input>

JavaScript

var viewModel = {
    newAction: ko.observable("")
};

ko.applyBindings(viewModel);

viewModel.newAction.subscribe(function(value){
    if (!value) return;
    alert("new action: " + value);
    viewModel.newAction("");
});