php 61 lines · 8 steps

Streaming job progress with SSE in Laravel

An invokable controller pushes live job-progress updates to the browser using Server-Sent Events.

Explained by highlit

Laravel Advanced server-sent-events streaming polling invokable-controller real-time

1<?php
2 
3namespace App\Http\Controllers;
4 
5use App\Repositories\JobProgressRepository;
6use Illuminate\Http\Request;
7use Symfony\Component\HttpFoundation\StreamedResponse;
8 
9class JobProgressStreamController extends Controller
10{
11    public function __construct(private JobProgressRepository $progress)
12    {
13    }
14 
15    public function __invoke(Request $request, string $jobId): StreamedResponse
16    {
17        $response = new StreamedResponse(function () use ($jobId) {
18            $lastStatus = null;
19 
20            while (! connection_aborted()) {
21                $snapshot = $this->progress->find($jobId);
22 
23                if ($snapshot && $snapshot->status !== $lastStatus) {
24                    $lastStatus = $snapshot->status;
25 
26                    $this->send('progress', [
27                        'status' => $snapshot->status,
28                        'percent' => $snapshot->percent,
29                        'message' => $snapshot->message,
30                    ]);
31 
32                    if (in_array($snapshot->status, ['completed', 'failed'], true)) {
33                        $this->send('done', ['status' => $snapshot->status]);
34                        break;
35                    }
36                }
37 
38                usleep(750_000);
39            }
40        });
41 
42        $response->headers->set('Content-Type', 'text/event-stream');
43        $response->headers->set('Cache-Control', 'no-cache');
44        $response->headers->set('Connection', 'keep-alive');
45        $response->headers->set('X-Accel-Buffering', 'no');
46 
47        return $response;
48    }
49 
50    private function send(string $event, array $data): void
51    {
52        echo "event: {$event}\n";
53        echo 'data: ' . json_encode($data) . "\n\n";
54 
55        if (ob_get_level() > 0) {
56            ob_flush();
57        }
58 
59        flush();
60    }
61}

01 / 01

STEP 01

Walkthrough

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Three takeaways

1Server-Sent Events let you push updates over one long-lived HTTP response without WebSockets.
2Checking connection_aborted() and diffing state keeps a streaming loop cheap and safe from runaway output.
3Disabling buffering at the framework, PHP, and proxy layers is what actually makes streamed chunks reach the client.

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