Added cache conditional helper

Author: Geolim4

README.md

@@ -212,6 +212,17 @@ EventManager::getInstance()->unbindEventCallback('onCacheGetItem', 'myCallbackNa
 
 More information about the implementation and the events available on the [Wiki](https://github.com/PHPSocialNetwork/phpfastcache/wiki/%5BV6%5D-Introducing-to-events)
 
+---------------------------
+Introducing new helpers
+---------------------------
+:books: As of the V6, PhpFastCache provides some helpers to make your code easier.
+
+- The [ActOnAll Helper](https://github.com/PHPSocialNetwork/phpfastcache/wiki/%5BV6%CB%96%5D-Act-on-all-instances) to help you to act on multiple instance at once.
+- The [CacheConditional Helper](https://github.com/PHPSocialNetwork/phpfastcache/wiki/%5BV6%CB%96%5D-Cache-Conditional) to help you to make the basic conditional statement more easier.
+- The [Psr16 adapter](https://github.com/PHPSocialNetwork/phpfastcache/wiki/%5BV6%CB%96%5D-Psr16-adapter) to keep it simple as explained above.
+
+May more will come in the future, feel free to contribute !
+
 ---------------------------
 As Fast To Implement As Opening a Beer
 ---------------------------

src/phpFastCache/Helper/CacheConditionalHelper.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ *
+ * This file is part of phpFastCache.
+ *
+ * @license MIT License (MIT)
+ *
+ * For full copyright and license information, please see the docs/CREDITS.txt file.
+ *
+ * @author Khoa Bui (khoaofgod)  <khoaofgod@gmail.com> http://www.phpfastcache.com
+ * @author Georges.L (Geolim4)  <contact@geolim4.com>
+ *
+ */
+namespace phpFastCache\Helper;
+
+use Psr\Cache\CacheItemPoolInterface;
+
+/**
+ * Class CacheConditional
+ * @package phpFastCache\Helper
+ */
+class CacheConditionalHelper
+{
+    /**
+     * @var CacheItemPoolInterface
+     */
+    protected $cacheInstance;
+
+    /**
+     * CachePromise constructor.
+     * @param CacheItemPoolInterface $cacheInstance
+     */
+    public function __construct(CacheItemPoolInterface $cacheInstance)
+    {
+        $this->cacheInstance = $cacheInstance;
+    }
+
+    /**
+     * @param string $cacheKey
+     * @param callable $callback
+     */
+    public function get($cacheKey, callable $callback)
+    {
+        $cacheItem = $this->cacheInstance->getItem($cacheKey);
+
+        if(!$cacheItem->isHit())
+        {
+            $cacheItem->set($callback());
+            $this->cacheInstance->save($cacheItem);
+        }
+
+        return $cacheItem->get();
+    }
+}

tests/CacheConditional.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * @author Khoa Bui (khoaofgod)  <khoaofgod@gmail.com> http://www.phpfastcache.com
+ * @author Georges.L (Geolim4)  <contact@geolim4.com>
+ */
+
+use phpFastCache\CacheManager;
+use phpFastCache\Helper\CacheConditionalHelper as CacheConditional;
+use phpFastCache\Helper\TestHelper;
+use Psr\Cache\CacheItemPoolInterface;
+
+chdir(__DIR__);
+require_once __DIR__ . '/../src/autoload.php';
+$testHelper = new TestHelper('Cache Promise');
+$defaultDriver = (!empty($argv[ 1 ]) ? ucfirst($argv[ 1 ]) : 'Files');
+$cacheInstance = CacheManager::getInstance($defaultDriver, []);
+$cacheKey = 'cacheKey';
+$RandomCacheValue = str_shuffle(uniqid('pfc', true));
+
+
+/**
+ * Missing cache item test
+ */
+$cacheValue = (new CacheConditional($cacheInstance))->get($cacheKey, function() use ($cacheKey, $testHelper, $RandomCacheValue){
+    /**
+     * No parameter are passed
+     * to this closure
+     */
+    $testHelper->printText('Entering in closure as the cache item does not come from the cache backend.');
+
+    /**
+     * Here's your database/webservice/etc stuff
+     */
+
+    return $RandomCacheValue . '-1337';
+});
+
+if($cacheValue === $RandomCacheValue . '-1337'){
+    $testHelper->printPassText(sprintf('The cache promise successfully returned expected value "%s".', $cacheValue));
+}else{
+    $testHelper->printFailText(sprintf('The cache promise returned an unexpected value "%s".', $cacheValue));
+}
+
+/**
+ * Existing cache item test
+ */
+$cacheItem = $cacheInstance->getItem($cacheKey);
+$RandomCacheValue = str_shuffle(uniqid('pfc', true));
+$cacheItem->set($RandomCacheValue);
+$cacheInstance->save($cacheItem);
+
+/**
+ * Remove objects references
+ */
+$cacheInstance->detachAllItems();
+unset($cacheItem);
+
+$cacheValue = (new CacheConditional($cacheInstance))->get($cacheKey, function() use ($cacheKey, $testHelper, $RandomCacheValue){
+    /**
+     * No parameter are passed
+     * to this closure
+     */
+    $testHelper->printFailText('Unexpected closure call.');
+    return $RandomCacheValue . '-1337';
+});
+
+if($cacheValue === $RandomCacheValue){
+    $testHelper->printPassText(sprintf('The cache promise successfully returned expected value "%s".', $cacheValue));
+}else{
+    $testHelper->printFailText(sprintf('The cache promise returned an unexpected value "%s".', $cacheValue));
+}
+
+$cacheInstance->clear();
+$testHelper->terminateTest();