Laravel QR

Appearance

Caching ​

Drawing a code takes a few milliseconds; a page full of styled codes, or a large PNG, takes longer. Codes can be written once and served from the cache after that.

Within a request ​

A code drawn twice in one request, with the same content, style, format and options, is written once. Nothing to set up.

Across requests ​

php
Qr::url($url)->cache()->svg();        // the default lifetime, qr.cache.ttl (a week)
Qr::url($url)->cache(3600)->png(600); // seconds, or a DateInterval or DateTimeInterface

or for every code, in config/qr.php:

php
'cache' => [
    'enabled' => true,              // QR_CACHE
    'store' => null,                // a cache store by name; the default store when null
    'ttl' => 604800,
    'prefix' => 'qr',
],

and opt one code out:

php
Qr::url($url)->withoutCache()->svg();

A code is cached by everything that decides how it looks: its content, its style, the format and its options, and the versions of the shapes it uses. Change any of them and it is drawn again.

Some codes cannot be cached, and are drawn fresh each time:

  • a closure filter without a name (give it one: ->filter($closure, name: 'striped'));
  • a gradient of your own that the registry cannot store;
  • a shape of your own with settings that does not implement Configurable.

Making cached codes stale ​

php
Qr::forget($code);                    // one code, every format and size
Qr::forget('https://example.com', 'brand');   // content and the styles it was made with
Qr::flush();                          // every code
bash
php artisan qr:clear

Nothing is deleted; the codes' keys change, and the old entries expire. After changing how a shape of your own draws, raise its version, or raise qr.cache.version to make every code stale.

Events ​

QrCacheHit and QrCacheMissed tell when the cache store was asked; QrRendered says whether the code was drawn or served ($event->cached). See Events and Monocle.