This package is highly inspired by and partly forked from laracasts/matryoshka
Requires:
From the command line, run:
composer require justustheis/kaish
For your Laravel app, open config/app.php
and, within the providers
array, append:
JustusTheis\Kaish\KaishServiceProvider::class
This will bootstrap the package into Laravel.
For this package to function properly, you must use a Laravel cache driver that supports tagging (like Cache::tags('foo')
). Drivers such as Memcached and Redis support this feature.
Check your .env
file, and ensure that your CACHE_DRIVER
choice accomodates this requirement:
CACHE_DRIVER=memcached
With the package now installed, you may use the provided @cache
Blade directive anywhere in your views, like so:
@cache('my-cache-key')
<div>
<h1>Hello World</h1>
</div>
@endcache
By surrounding this block of HTML with the @cache
and @endcache
directives, we're asking the package to cache the given HTML. Now this example is trivial, however, you can imagine a more complex view that includes various nested caches, as well as lazy-loaded relationship calls that trigger additional database queries. After the initial page load that caches the HTML fragment, each subsequent refresh will instead pull from the cache. As such, those additional database queries will never be executed.
Please keep in mind that, in production, this will cache the HTML fragment "forever." For local development, on the other hand, we'll automatically flush the relevant cache for you each time you refresh the page. That way, you may update your views and templates however you wish, without needing to worry about clearing the cache manually.
Now because your production server will cache the fragments forever, you'll want to add a step to your deployment process that clears the relevant cache.
Cache::tags('views')->flush();
While you're free to hard-code any string for the cache key, the true power of Russian-Doll caching comes into play when we use a timestamp-based approach.
Consider the following fragment:
@cache('my-cache-key', $post)
<article>
<h2>{{ $post->title }}></h2>
<p>Written By: {{ $post->author->username }}</p>
<div class="body">{{ $post->body }}</div>
</article>
@endcache
In this example, we're passing the $post
object as well as a string based key to the @cache
directive. The package will then look for a getCacheKey()
method on the model. We've already done that work for you; just have your Eloquent model use the JustusTheis\Kaish\Kaishable
trait, like so:
use JustusTheis\Kaish\Kaishable;
class Post extends Eloquent
{
use Kaishable;
}
Alternatively, you may use this trait on a parent class that each of your Eloquent models extend.
That should do it! Now, the cache key for this fragment will include the object's id
and updated_at
timestamp: my-cache-key.
App\Post/1-13241235123`.
The key is that, because we factor the
updated_at
timestamp into the cache key, whenever you update the given post, the cache key will change. This will then, in effect, bust the cache!
In order for this technique to work properly, it's vital that we have some mechanism to alert parent relationships (and subsequently bust parent caches) each time a model is updated. Here's a basic workflow:
- Model is updated in the database.
- Its
updated_at
timestamp is refreshed, triggering a new cache key for the instance. - The model "touches" (or pings) its parent.
- The parent's
updated_at
timestamp, too, is updated, which busts its associated cache. - Only the affected fragments re-render. All other cached items remain untouched.
Luckily, Laravel offers this "touch" functionality out of the box. Consider a Note
object that needs to alert its parent Card
relationship each time an update occurs.
<?php
namespace App;
use JustusTheis\Kaish\Kaishable;
use Illuminate\Database\Eloquent\Model;
class Note extends Model
{
use Kaishable;
protected $touches = ['card'];
public function card()
{
return $this->belongsTo(Card::class);
}
}
Notice the $touches = ['card']
portion. This instructs Laravel to ping the card
relationship's timestamps each time the note is updated.
Now, everything is in place. You might render your view, like so:
resources/views/cards/_card.blade.php
@cache('my-cache-key', $card)
<article class="Card">
<h2>{{ $card->title }}</h2>
<ul>
@foreach ($card->notes as $note)
@include ('cards/_note')
@endforeach
</ul>
</article>
@endcache
resources/views/cards/_note.blade.php
@cache('my-cache-key', $note)
<li>{{ $note->body }}</li>
@endcache
Notice the Russian-Doll style cascading for our caches; that's the key. If any note is updated, its individual cache will clear - along with its parent - but any siblings will remain untouched.
You won't always want to cache model instances; you may wish to cache a Laravel collection as well! No problem.
@cache('my-cache-key', $posts)
@foreach ($posts as $post)
@include ('post')
@endforeach
@endcache
Now, as long as the $posts
collection contents does not change, that @foreach
section will never run. Instead, as always, we'll pull from the cache.
Behind the scenes, this package will detect that you've passed a Laravel collection to the cache
directive, and will subsequently generate a unique cache key for the collection.