Improve Automatic Actions plugin api

app/Action/TaskAssignCategoryLabel.php

@@ -12,6 +12,17 @@ use Kanboard\Integration\GithubWebhook;
  */
 class TaskAssignCategoryLabel extends Base
 {
+    /**
+     * Get automatic action description
+     *
+     * @access public
+     * @return string
+     */
+    public function getDescription()
+    {
+        return t('Change the category based on an external label');
+    }
+
     /**
      * Get the list of compatible events
      *
@@ -64,7 +75,7 @@ class TaskAssignCategoryLabel extends Base
     {
         $values = array(
             'id' => $data['task_id'],
-            'category_id' => isset($data['category_id']) ? $data['category_id'] : $this->getParam('category_id'),
+            'category_id' => $this->getParam('category_id'),
         );
 
         return $this->taskModification->update($values);
@@ -79,6 +90,6 @@ class TaskAssignCategoryLabel extends Base
      */
     public function hasRequiredCondition(array $data)
     {
-        return $data['label'] == $this->getParam('label');
+        return $data['label'] == $this->getParam('label') && empty($data['category_id']);
     }
 }