Support for image_url property within Slack attachments

Author: Kenneth

src/Illuminate/Notifications/Channels/SlackWebhookChannel.php

@@ -89,6 +89,7 @@ protected function attachments(SlackMessage $message)
                 'footer' => $attachment->footer,
                 'footer_icon' => $attachment->footerIcon,
                 'ts' => $attachment->timestamp,
+                'image_url' => $attachment->imageUrl,
             ]);
         })->all();
     }

src/Illuminate/Notifications/Messages/SlackAttachment.php

@@ -76,6 +76,13 @@ class SlackAttachment
      */
     public $timestamp;
 
+    /**
+     * The attachment's image url.
+     *
+     * @var string
+     */
+    public $imageUrl;
+
     /**
      * Set the title of the attachment.
      *
@@ -218,4 +225,18 @@ public function timestamp(Carbon $timestamp)
 
         return $this;
     }
+
+    /**
+     * Set the image url.
+     *
+     * @param  string $url
+     *
+     * @return $this
+     */
+    public function imageUrl($url)
+    {
+        $this->imageUrl = $url;
+
+        return $this;
+    }
 }