Is this a true long polling?

Question

After lot of trials,I am successfully able to maintain continous server connection with database. Now code keet cheking and show the messages,if there are new in database.<

Answer 1

Polling is a bit harder than a simple while : just because generally all things you output to the browser will be interpreted when complete. Your example is quite clear :

success:function(data) {
    var json = data;
    $("#commidwin").append(json['msg']);
    last_msg_id = json["last_msg_id_db"];
    setTimeout("load_msgs()", 1000);
},

jQuery will wait until the response is complete to build your data variable and then will call your success callback.

One way to create long-polling is to have a task and a follower :

• the task is the "infinite" loop, it displays nothing but just catch and trigger events, put in a "box".

• the follower is an ajax call made every X seconds, it looks inside the "box" filled by the task, and immediately act inside the page.

Here is an example of long-polling, there is no follower, just an event (release) that stops the poll, but you'll get the idea :

 $time)
        {
            $result = htmlentities(file_get_contents('poll.txt'));
            $poll = false;
        }

        // Of course, else your polling will kill your resources!
        $number_of_tries++;
        sleep(1);
    }

    // Outputs result
    echo "Number of tries : {$number_of_tries}
{$result}";
    die();
}

// Here we catch the release form
if (isset($_GET['release']))
{
    $data = '';
    if (isset($_GET['data']))
    {
        $data = $_GET['data'];
    }
    file_put_contents('poll.txt', $data);
    die();
}
?>








Give me some text here :













Result after releasing polling :

Demonstration : here.