JS - Create script tag to load JSON-D data for SEO

jsond-script-loading.html

// JSON-D SCRIPT LOADING
// @see         https://www.html5rocks.com/en/tutorials/speed/script-loading/

<link rel="subresource" href="//www.timothysofnewark.com/blog/js/tims-jsond.js">

<script type="text/javascript">
		document.documentElement.className = 'js';

		var scripts = [
		  'tims-jsond.js'
		];
		var src;
		var script;
		var pendingScripts = [];
		var firstScript = document.scripts[0];

		// Watch scripts load in IE
		function stateChange() {
		  // Execute as many scripts in order as we can
		  var pendingScript;
		  while (pendingScripts[0] && pendingScripts[0].readyState == 'loaded') {
		    pendingScript = pendingScripts.shift();
		    // avoid future loading events from this script (eg, if src changes)
		    pendingScript.onreadystatechange = null;
		    // can't just appendChild, old IE bug if element isn't closed
		    firstScript.parentNode.insertBefore(pendingScript, firstScript);
		  }
		}

		// loop through our script urls
		while (src = scripts.shift()) {
		  if ('async' in firstScript) { // modern browsers
		    script = document.createElement('script');
		    script.async = false;
		    script.src = src;
		    script.type = 'application/ld+json';
		    document.head.appendChild(script);
		  }
		  else if (firstScript.readyState) { // IE<10
		    // create a script and add it to our todo pile
		    script = document.createElement('script');
		    pendingScripts.push(script);
		    // listen for state changes
		    script.onreadystatechange = stateChange;
		    // must set src AFTER adding onreadystatechange listener
		    // else we’ll miss the loaded event for cached scripts
		    script.src = src;
		  }
		  else { // fall back to defer
		    document.write('<script src="' + src + '" defer></'+'script>');
		  }
		}
</script>