Added sortDirection and some doc on Doctrine feed providers.

README.md

@@ -74,7 +74,11 @@ return $feed->getItems(12);
 
 ## Combine feeds
 
-*mixedfeed* can combine multiple social feeds so you can loop over them and use some common data fields such as `feedItemPlatform`, `normalizedDate` and `canonicalMessage`.
+*mixedfeed* can combine multiple social feeds so you can loop over them and use some common data fields such as `feedItemPlatform`, `normalizedDate` and `canonicalMessage`. *mixedfeed* will sort all your feed items by *descending* `normalizedDate`, but you can configure it to sort *ascending*: 
+
+```php
+new MixedFeed([…], MixedFeed::ASC);
+```
 
 Each feed provider must inject these three parameters in feed items:
 
@@ -115,8 +119,9 @@ No problem, you can easily create your own feed provider to use in *mixedfeed*.
 will inherit from `RZ\MixedFeed\AbstractFeedProvider`. Then you will have to implement each method from `FeedProviderInterface`:
 
 * `getDateTime` method to look for the critical datetime field in your feed.
-* `getFeed` method to consume your API endpoint with a count limit and take care of caching your responses.
-* `getCanonicalMessage` method to look for the important text content in your feed.
+* `getFeed` method to consume your API endpoint with a count limit and take care of caching your responses. 
+This method **must convert your own feed items into `\stdClass` objects.**
+* `getCanonicalMessage` method to look for the important text content in your feed items.
 * `getFeedPlatform` method to get a global text identifier for your feed items.
 * `isValid` method to check if API call has succeeded regarding feed content.
 * `getErrors` method to errors from API feed that did not succeed.
@@ -125,3 +130,62 @@ will inherit from `RZ\MixedFeed\AbstractFeedProvider`. Then you will have to imp
 Feel free to check our existing Feed providers to see how they work. And we strongly advise you to
 implement a caching system not to call your API endpoints at each request. By default, we use *Doctrine*’s caching
 system which has many storage options.
+
+### Create a feed provider from a *Doctrine* repository
+
+If you need to merge social network feeds with your own website articles, you can create a custom FeedProvider which wraps your Doctrine objects into `\stdClass` items. You’ll need to implement your `getFeed` method using an EntityManager:
+
+```php
+protected $entityManager;
+
+public function __construct(\Doctrine\ORM\EntityManagerInterface $entityManager)
+{
+    $this->entityManager = $entityManager;
+    $this->tags = $tags;
+    $this->timespan = $timespan;
+}
+
+protected function getFeed($count = 5)
+{
+    return array_map(
+        function (Article $article) {
+            $object = new \stdClass();
+            $object->native = $article;
+            return $object;
+        }, 
+        $this->entityManager->getRepository(Article::class)->findBy(
+            [],
+            ['datetime' => 'DESC'],
+            $count
+        )
+    );
+}
+```
+
+Then you can define your *date-time* and *canonical message* methods to look into this object:
+
+```php
+/**
+ * @inheritDoc
+ */
+public function getDateTime($item)
+{
+    if ($item->native instanceof Article) {
+        return $item->native->getDatetime();
+    }
+
+    return null;
+}
+
+/**
+ * @inheritDoc
+ */
+public function getCanonicalMessage($item)
+{
+    if ($item->native instanceof Article) {
+        return $item->native->getExcerpt();
+    }
+
+    return null;
+}
+```

composer.json

@@ -7,7 +7,7 @@
         {
             "name": "Ambroise Maupate",
             "email": "ambroise@rezo-zero.com",
-            "homepage": "http://www.rezo-zero.com",
+            "homepage": "https://www.rezo-zero.com",
             "role": "Lead developer"
         }
     ],
@@ -25,5 +25,8 @@
     },
     "autoload": {
         "psr-4": {"RZ\\MixedFeed\\": "src/"}
+    },
+    "require-dev": {
+        "squizlabs/php_codesniffer": "^3.3"
     }
 }

src/AbstractFeedProvider.php

@@ -39,7 +39,7 @@ abstract class AbstractFeedProvider implements FeedProviderInterface
      * @param int $count
      * @return array
      */
-    protected abstract function getFeed($count = 5);
+    abstract protected function getFeed($count = 5);
 
     /**
      * {@inheritdoc}

src/FeedProviderInterface.php

@@ -25,6 +25,8 @@
  */
 namespace RZ\MixedFeed;
 
+use RZ\MixedFeed\Exception\FeedProviderErrorException;
+
 interface FeedProviderInterface
 {
     /**
@@ -43,13 +45,14 @@ public function getFeedPlatform();
      *
      * @param  integer $count
      * @return array
+     * @throws FeedProviderErrorException
      */
     public function getItems($count = 5);
 
     /**
      * Get a \DateTime object from a social feed item.
      *
-     * @param  stdClass $item
+     * @param \stdClass $item
      * @return \DateTime
      */
     public function getDateTime($item);

src/MixedFeed.php

@@ -33,15 +33,23 @@
  */
 class MixedFeed extends AbstractFeedProvider
 {
+    const ASC = 'ASC';
+    const DESC = 'DESC';
+
     protected $providers;
+    /**
+     * @var string
+     */
+    protected $sortDirection;
 
     /**
      * Create a mixed feed composed of heterogeneous feed
      * providers.
      *
-     * @param array $providers
+     * @param array  $providers
+     * @param string $sortDirection
      */
-    public function __construct(array $providers = [])
+    public function __construct(array $providers = [], $sortDirection = MixedFeed::DESC)
     {
         foreach ($providers as $provider) {
             if (!($provider instanceof FeedProviderInterface)) {
@@ -50,6 +58,7 @@ public function __construct(array $providers = [])
         }
 
         $this->providers = $providers;
+        $this->sortDirection = $sortDirection;
     }
 
     /**
@@ -79,6 +88,10 @@ public function getItems($count = 5)
                 if ($aDT == $bDT) {
                     return 0;
                 }
+                // ASC sorting
+                if ($this->sortDirection === static::ASC) {
+                    return ($aDT > $bDT) ? 1 : -1;
+                }
                 // DESC sorting
                 return ($aDT > $bDT) ? -1 : 1;
             });