- Refactors sending queue worker by breaking it into smaller tasks

- Adds arrayUnique method to Helpers for multidimensional arrays

lib/Cron/Workers/SendingQueue/Tasks/Posts.php

@@ -0,0 +1,29 @@
+<?php
+namespace MailPoet\Cron\Workers\SendingQueue\Tasks;
+
+use MailPoet\Models\NewsletterPost;
+
+if(!defined('ABSPATH')) exit;
+
+class Posts {
+  static function extractAndSave(array $newsletter) {
+    if(empty($newsletter['rendered_body']['html']) || empty($newsletter['id'])) {
+      return;
+    }
+    preg_match_all(
+      '/data-post-id="(\d+)"/ism',
+      $newsletter['rendered_body']['html'],
+      $matached_posts);
+    $matached_posts = $matached_posts[1];
+    if(!count($matached_posts)) {
+      return $newsletter;
+    }
+    foreach($matached_posts as $post) {
+      $newletter_post = NewsletterPost::create();
+      $newletter_post->newsletter_id = $newsletter['id'];
+      $newletter_post->post_id = $post;
+      $newletter_post->save();
+    }
+    return $newsletter;
+  }
+}