JSFiddle - React, Tailwind, and code Playground

HTML

<textarea dataref="source" class="textarea"></textarea>
    <input type="button" class="gen" value="generate">
    <div class="result"></div>

CSS

.result {
    border: 1px solid red;
    width: 300px;
    height: 150px;
    }
    .textarea {
    	width: 300px;
    	height: 150px;
    background-color:#eee;
        
    }

JavaScript

$(document).ready(function() {
    	
    	var btn = $('.gen');
    	btn.on('click', function() {
    		var areaTxt = $('.textarea').val();
    		var div = $('.result');
    		div.html(areaTxt);
            $("textarea").each(function(){
                var attr = 
                $(this).attr('dataref');
                if (typeof attr !== typeof undefined && attr !== false && attr == 'source') {
                   
$(this).attr('style', 'background-color: #eee !important');
   
}
            })
    	});
    	
    });