Automatically create tweets for new posts

web/modules/custom/custom/config/schema/custom.schema.yml

@@ -0,0 +1,6 @@
+opdavies_talks.settings:
+  type: config_object
+  label: 'Talks module configuration'
+  mapping:
+    zapier_post_tweet_url:
+      type: string

web/modules/custom/custom/custom.services.yml

@@ -3,5 +3,9 @@ services:
     tags:
       - { name: event_subscriber }
 
+  Drupal\custom\EventSubscriber\PushBlogPostToSocialMedia:
+    tags:
+      - { name: event_subscriber }
+
   Drupal\custom\Service\TalkCounter:
     autowire: true

web/modules/custom/custom/src/Entity/Node/Post.php

@@ -22,4 +22,12 @@ class Post extends Node implements ContentEntityBundleInterface {
     return (bool) $this->get('field_has_tweet')->getString();
   }
 
+  public function toTweet(): string {
+    // TODO: Add tags.
+
+    $parts = [$this->label(), $this->url('canonical', ['absolute' => TRUE])];
+
+    return implode(PHP_EOL . PHP_EOL, $parts);
+  }
+
 }

web/modules/custom/custom/src/EventSubscriber/PushBlogPostToSocialMedia.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\custom\EventSubscriber;
+
+use Drupal\custom\Entity\Node\Post;
+use Drupal\hook_event_dispatcher\Event\Entity\BaseEntityEvent;
+use Drupal\hook_event_dispatcher\HookEventDispatcherInterface;
+use Drupal\node\NodeInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+final class PushBlogPostToSocialMedia implements EventSubscriberInterface {
+
+  /**
+   * @inheritDoc
+   */
+  public static function getSubscribedEvents() {
+    return [
+      HookEventDispatcherInterface::ENTITY_PRE_SAVE => 'onEntityPreSave',
+    ];
+  }
+
+  public function onEntityPresave(BaseEntityEvent $event): void {
+    $entity = $event->getEntity();
+
+    if ($entity->getEntityTypeId() != 'node') {
+      return;
+    }
+
+    /** @var NodeInterface $entity */
+    if ($entity->bundle() != 'post') {
+      return;
+    }
+
+    if (!$entity->isPublished()) {
+      return;
+    }
+
+    // TODO: Check that the post has not already been pushed.
+
+    $url = \Drupal::configFactory()->get('opdavies_talks.config')
+      ->get('zapier_post_tweet_url');
+
+    \Drupal::httpClient()->post($url, [
+      'form_params' => [
+        'message' => $entity->toTweet(),
+      ],
+    ]);
+  }
+
+}