When a user chooses a date from the drop-down list, the number of nights changes according to that new date.
Following this tutorial www.w3schools.com/php/php_ajax_database.asp I wrote the following code, but when I change the date on the list, I just get a message saying undefined in the <div id="stats">
<?php
$dates = "";
foreach ($check_ins as $check_in):
$dates .= '<option value= "' . $check_in['check_in'] . '">' . $check_in['check_in'] . '</option>';
endforeach;
$nights = $check_ins[0]['nights'];
if (!empty($_POST['newDate'])){
$nights = 0;
foreach ($check_ins as $check_in):
if ($check_in['check_in'] === $_POST['newDate']){
$nights += $check_in['nights'];
}
endforeach;
}
?>
<html>
<head>
<title>Bookings stats</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script>
/*function dynamicDates() {
var d = $("#dates").val();
$.post("metrily.php", { newDate: d });
}*/
function dynamicDates(newDate){
if (newDate == ""){
document.getElementById("stats").innerHTML = "";
return;
} else {
xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
document.getElementById("stats").innerHTML = xmlhttp.responseTest;
}
};
xmlhttp.open("POST", "hotel.php", true);
xmlhttp.send("newDate=" + newDate);
}
}
</script>
</head>
<body>
<b>Check-in: </b>
<select id="dates" name="check_in" onchange="dynamicDates(this.value)"><?php echo $dates; ?></select>
<br></br>
<div id="stats">
<b>Nights: </b><?php echo $nights; ?>
</div>
</body>
</html>
