Fire javascript event after search is completed and there is no search results

I found a solution. I added the following code to custom component to catch the ajax event, parse the response data and search for the text "No search results found."

<script>
$(function() {

	/* Part 1. Check if no results when page is loaded  */
	if ($('.InfoMessage p').text() === 'No search results found.') {
		console.log('Show chat');
	}

	/* Part 2. Ajax call event listener */
	var _send = XMLHttpRequest.prototype.send;
	XMLHttpRequest.prototype.send = function() {
		this.addEventListener("readystatechange", function() {
			if(this.readyState == 4){
				var jsonObj = $.parseJSON(this.responseText);
				if (jsonObj.response.components.length !== 0) {
					var code = $(jsonObj.response.components[0].content);
					var resultText = code.find('.InfoMessage p').text();
					if (resultText === 'No search results found.') {
						console.log('Show chat');
					}
				}
			}
		}, false);
	_send.apply(this, arguments);
	}
});
</script>