PHP code example of xtain / psr6-null

1. Go to this page and download the library: Download xtain/psr6-null library. Choose the download type require.

2. Extract the ZIP file and open the index.php.

3. Add this code to the index.php.
    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

xtain / psr6-null example snippets


namespace MyPackage;

use Psr\Cache\CacheItemPoolInterface;

class MyCode
{

    public function setCache(CacheItemPoolInterface $cache = null)
    {
        $this->cache = $cache;
    }

    /**
     * Can return an instance of null, which is bad!
     *
     * @return null CacheItemPoolInterface
     */
    public function getCache()
    {
        return $this->cache;
    }

    private function internalHeavyMethod()
    {
        $cacheKey = 'myKey';
        
        // you need to check first, if there is a cache instance around
        if ($this->getCache() !== null && $this->getCache()->hasItem($cacheKey) === true) {
            // cache is available + it has a cache hit!
            return $this->getCache()->getItem($cacheKey);
        }
        
        $result = do_something_heavy();
        
        // you need to check first, if there is a cache instance around
        if ($this->getCache() !== null) {
            $item = $this->getCache()->getItem($cacheKey);
            $item->set($result);
            $this->getCache()->save($item);
        }
        
        return $result;
    }
}


namespace MyPackage;

use Psr\Cache\CacheItemPoolInterface;
use XTAIN\Psr\Cache\NullCacheItemPool;
use XTAIN\Psr\Cache\CacheItemPoolAwareInterface;
use XTAIN\Psr\Cache\CacheItemPoolAwareTrait;

class MyCode implements CacheItemPoolAwareInterface
{
    use CacheItemPoolAwareTrait;

    /**
     * You could ey';
        
        if ($this->getCache()->hasItem($cacheKey) === true) {
            // cache is available + it has a cache hit!
            return $this->getCache()->getItem($cacheKey);
        }
        
        $result = do_something_heavy();
        
        $item = $this->getCache()->getItem($cacheKey);
        $item->set($result);
        $this->getCache()->save($item);
        
        return $result;
    }
}