GTM_track_autocomplete.js

// GTM custom HTML tag for tracking incomplete searches
// logic: if user starts typing, start a timer. Stop the timer when user is idle 2.5 seconds
// then push the event on the DL

(function() {
	var timer, firstResult, searchText;
	var waiting = false;

	var waitTime = 2500; // milliseconds

	function waitForMoreKeys(msec) {
		
		if (!waiting) {
			waiting = true;
  			timer = setTimeout(function(){

  				// scrape your datalayer key/values here
  				searchText = $("#mapSearchInput").val().trim();
  				firstResult = $("#results > a:nth-child(1) > span").text().trim();
				
				dataLayer.push( {
					'event': 'mapSearchInput search',
					'firstResult': typeof firstResult === "undefined" ? '(none)' : firstResult.toLowerCase(),
					'searchInput':  searchText ? searchText.toLowerCase() : '(none)'
				});
  				
  				waiting = false;
  			}, msec);
  		}
	}

	function stopWaiting() {
		clearTimeout(timer);
		waiting = false;
	}

	// replace this with your searchbox ID
	$("#mapSearchInput").keydown(function() {
		if (waiting)
			stopWaiting();

		waitForMoreKeys(waitTime);
	});
})();