JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://raw.github.com/enyojs/onyx/master/source/package.js"></script>

JavaScript

enyo.kind({
    name: "ex.About", 
    kind: "onyx.Popup", 
    modal: true,
    centered: false,
    handlers:{
        onShow:"_show"
    },
    attributes:{class:"my-popup"},         
    components: [
        {name:"button", kind:"onyx.Button", content:"Click Me!"}
    ],
    _show: function () { 
        enyo.log("Popup is now shown, you can set the dynamic content");
        
        this.$.button.setContent("I was updated in _show");
    }
});

enyo.kind({
    name:"ex.App",
    kind:"Control",
    components:[
        {kind:"onyx.Button", content:"show popup", ontap:"showAbout"},
        {name:"about", kind:"ex.About"}
    ],
    showAbout:function() {
        this.$.about.show();
    }
});

new ex.App().renderInto(document.body)