php – How to process multiple echoes in one AJAX request?

Question:

Let's say there is an ajax request like this:

$.ajax({
    url: "action.php",
    success: function (response) {
    //какое-то действие здесь
    };
});

И action.php:

   <?php 
    while(true){
    //выполняется какая-то логика
    echo json_encode(//какие-то данные);
    }
   ?>

Is it possible after each echo process this data in an ajax request and wait until the next piece of data arrives?

Answer:

Use a so called comet :

Server side:

for($i=0; $i < 10; $i++) {
    sleep(1);

    $arr = array("time" => time());

    echo "<script>parent.callback(" . json_encode($arr) . ")</script>";

    flush();
    ob_flush();
}

On the client side:

<iframe id="comet"></iframe>
<script>
function start() {
    document.getElementById('comet').src = 'comet.php';
}
function stop() {
    document.getElementById('comet').src = '';
}

function callback(data) {
    document.getElementById("div").innerHTML += JSON.stringify(data);
}
</script>

<input type="button" onclick="start()" value="start">
<input type="button" onclick="stop()" value="stop">
<div id="div"></div>