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