JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://knockoutjs.com/downloads/knockout-3.2.0.js"></script>
<voting params="votes: votes, yourVote: yourVote"></voting>

<template id="voting-tpl">
    <div data-bind="click:function(){callback(1)}">Up</div>
    <div data-bind="text: votes"></div>
    <div data-bind="click:function(){callback(-1)}">Down</div>
</template>

JavaScript

ko.components.register('voting', {
    viewModel: function(params) {
        var self        = this;
        this.votes      = params.votes;
        this.yourVote   = params.yourVote;
        
        this.callback   = function(num){
            self.yourVote(parseInt(num));
            self.votes( self.votes() + parseInt(num) );
        };
    },
    template: { element: 'voting-tpl' }
});

function Vm(){
    this.votes = ko.observable(5);
    this.yourVote = ko.observable(0);
}

ko.applyBindings(new Vm() );