Method

ServerSentEvents::comment

Send a comment: the browser ignores it, so it keeps the stream alive through proxies and lets a handler find out that the client is gone.

Description#

public ServerSentEvents::comment(
    string $text = ''
): void

Parameters#

$text string = '': What the comment says; line breaks become spaces

Errors / Exceptions#

Exception	When
`IOException`	When the client is gone

Examples#

Example 1Keep-alive comments

use Swerve\ClientRequest;
use Swerve\RequestHandler;
use Swerve\ServerSentEvents;

$app = new RequestHandler(function (ClientRequest $request) {
    $events = new ServerSentEvents($request);
    for ($i = 0; $i < 2; ++$i) {
        phasync::sleep(0.05);       // in production: some seconds without news
        $events->comment('keep-alive');   // the browser ignores it; a client that left makes it throw
    }
    $events->send('news at last');
});

if (debug_backtrace()) {
    return $app;   // swerve loads this file: it is the application's swerve.php
}

// Run directly: serve the application with swerve, and send it requests
require __DIR__ . '/../serve.php';
serve(__FILE__, ["GET /news HTTP/1.1\r\nHost: example\r\n\r\n"]);

Output

HTTP/1.1 200 OK
content-type: text/event-stream
cache-control: no-cache
x-accel-buffering: no
Server: Swerve
Transfer-Encoding: chunked
Connection: close

e
: keep-alive


e
: keep-alive


14
data: news at last


0