PHP Instant messenger - php

Question

I am trying to make a messenger using PHP and SQL
This is my code
<form action="send_post.php" method="post">
<h3>Name:</h3>
<input type="text" name="name">
<h3>Message:</h3>
<input type="text" name="message">
<input type="submit">
</form>
<?php
$servername = "servername";
$username = "username";
$password = "password";
$dbname = "dbname";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT id, name, message FROM chat";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
while(1){
ob_start();
echo "" . $row["name"]. " - " . $row["message"]. "<br>";
sleep(10);
echo "" . $row["name"]. " - " . $row["message"]. "<br>";
ob_end_clean();
}
}
}
$conn->close();
?>
However this does not work, is there any reason for this?
The problems started once I added the infinite while loop to refresh the messages.

Answer 1

PHP works serversided, which means that the client(guest) requests a page that the server then "compiles" to then send to the client as a clientsided language such as HTML. If the PHP code never reaches an end/stop the client browser is going to think the server stopped responding and give an error.
To achieve what you are trying to do you might want to look into something like JQuery AJAX which allows for the client to fetch data from the server seperatly from the main request. That way you can have one file showing only the messages and request that file on a timer, while having the form as usual page load. You can however also make the form dynamic using JQuery AJAX
UPDATE You can look at this blogpost to get an idea of what I'm talking about.