jQuery addClass example

Change class name on click in jQuery

by enorl76

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdn.rawgit.com/kriskowal/q/v1.5.1/q.js"></script>
<div id="banner-message">
  <p>Hello World</p>
  <button>Echo Request</button>
  <p id="log">
  Log
  </p>
</div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#log { font-size: 10px; }

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

// find elements
var $banner = $("#banner-message")
var $button = $("button")
var $log = $("#log")

Q_jqueryajax_promise = function() {

	return Q(
  	$.ajax({
    url: "https://postman-echo.com/get?foo1=bar1&foo2=bar2"
    })
  );

}

// handle click and add class
$button.on("click", function(){
  
  $log.css({color:'black'});
	$log.text('Starting request');
  
  Q_jqueryajax_promise().then(function(resp) {
  	$banner.text(JSON.stringify(resp));
  })
	.catch(function(reason) {
  	$log.text(JSON.stringify(reason,null,1));
		$log.css({color:'red'});
  });
  
})