JSFiddle - React, Tailwind, and code Playground
HTML
<div id="test" mydata='{"xkey":"xval","ykey":"yval"}'>
JavaScript
var mydata = JSON.parse($('#test').attr('mydata'));
console.log(mydata.xkey);
<div id="test" mydata='{"xkey":"xval","ykey":"yval"}'>
var mydata = JSON.parse($('#test').attr('mydata'));
console.log(mydata.xkey);