php return result, wait, return result

Question

I'm trying to create a loop that isn't breaking my browser. This loop should get information from a SQL database every 10 seconds. So I tried this in JavaScript:

while(true) {
    setTimeout(doRequest(), 10000);
}

but it's just freezing the browser because it starts before the page is ready. I tried window.onload, document.onload and also $(document).ready() but nothing worked. There was always the error: document.onload is not a function.
Then I read about the Web Worker, but that didn't work either. So I decided to use PHP instead:
JavaScript:

function test () {
    $.post(
        "../../modules/communicator.php",
        {
            action: "test"
        },
        function(result) {
            console.log(window.location.href);
        }
    );
}

communicator.php:

if ($_POST['action'] == 'test') {
    echo("test");
    sleep(5);
    echo("hello");
}

but it returns testhello after 5 seconds.

Is there a way to return a string, wait 5 seconds, and then return the next one?

You need setInterval(doRequest, 10000); (and remove the while loop). You were calling the function hundreds of thousands of times in the first second. — user5734311
– user5734311, Commented Jan 30, 2020 at 9:20
As for the 2nd part, first PHP finishes, then the result is sent back to the browser. — user5734311
– user5734311, Commented Jan 30, 2020 at 9:22
A setTimeout within a loop will not delay the loop. You just create an infinite number of setTimeouts that all fire 10 seconds later. — Turnip
– Turnip, Commented Jan 30, 2020 at 9:24
Also note that AJAX polling is an anti-pattern as it doesn't scale and causes server performance issues. If you need to keep the UI in sync with state changes on the server, use Websockets instead. — Rory McCrossan
– Rory McCrossan, Commented Jan 30, 2020 at 9:26
Here's an example of Ajax polling that might be worth a look - odds are you'd probably be better off with a websockets tutorial mind. — CD001
– CD001, Commented Jan 30, 2020 at 10:12

user12457887 · Accepted Answer · 2020-01-30 16:10:30Z

1

Thank you all! I fixed it! setInterval(doRequest, 10000);

answered Jan 30, 2020 at 16:10

user12457887

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

php return result, wait, return result

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related