Added an simple import system for attachment types.

src/Services/EntityImporter.php

@@ -0,0 +1,169 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 Jan Böhmer
+ * https://github.com/jbtronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\Services;
+
+
+use App\Entity\StructuralDBElement;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\MakerBundle\Str;
+use Symfony\Component\HttpFoundation\File\File;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+use Symfony\Component\Serializer\SerializerInterface;
+use Symfony\Component\Validator\Validator\ValidatorInterface;
+
+class EntityImporter
+{
+
+    protected $serializer;
+    protected $em;
+    protected $validator;
+
+    public function __construct(SerializerInterface $serializer, EntityManagerInterface $em, ValidatorInterface $validator)
+    {
+        $this->serializer = $serializer;
+        $this->em = $em;
+        $this->validator = $validator;
+    }
+
+    protected function configureOptions(OptionsResolver $resolver)
+    {
+        $resolver->setDefaults([
+           'csv_separator' => ';',
+            'format' => 'json',
+            'preserve_children' => true,
+            'parent' => null,
+            'abort_on_validation_error' => true
+        ]);
+    }
+
+    /**
+     * This methods deserializes the given file and saves it database.
+     * The imported elements will be checked (validated) before written to database.
+     * @param File $file The file that should be used for importing.
+     * @param string $class_name The class name of the enitity that should be imported.
+     * @param array $options Options for the import process.
+     * @return array An associative array containing an ConstraintViolationList and the entity name as key are returned,
+     * if an error happened during validation. When everything was successfull, the array should be empty.
+     */
+    public function fileToDBEntities(File $file, string $class_name, array $options = []) : array
+    {
+        $resolver = new OptionsResolver();
+        $this->configureOptions($resolver);
+
+        $options = $resolver->resolve($options);
+
+
+        $entities = $this->fileToEntityArray($file, $class_name, $options);
+
+        $errors = array();
+
+        //Iterate over each $entity write it to DB.
+        foreach ($entities as $entity) {
+            /** @var StructuralDBElement $entity */
+            //Move every imported entity to the selected parent
+            $entity->setParent($options['parent']);
+
+            //Validate entity
+            $tmp = $this->validator->validate($entity);
+
+            //When no validation error occured, persist entity to database (cascade must be set in entity)
+            if ($tmp === null) {
+                $this->em->persist($entity);
+            } else { //Log validation errors to global log.
+                $errors[$entity->getFullPath()] = $tmp;
+            }
+        }
+
+        //Save changes to database, when no error happened, or we should continue on error.
+        if (empty($errors) || $options['abort_on_validation_error'] == false) {
+            $this->em->flush();
+        }
+
+        return $errors;
+    }
+
+    /**
+     * This method converts (deserialize) a (uploaded) file to an array of entities with the given class.
+     *
+     * The imported elements will NOT be validated. If you want to use the result array, you have to validate it by yourself.
+     * @param File $file The file that should be used for importing.
+     * @param string $class_name The class name of the enitity that should be imported.
+     * @param array $options Options for the import process.
+     * @return array An array containing the deserialized elements.
+     */
+    public function fileToEntityArray(File $file, string $class_name, array $options = []) : array
+    {
+        $resolver = new OptionsResolver();
+        $this->configureOptions($resolver);
+
+        $options = $resolver->resolve($options);
+
+        //Read file contents
+        $content = file_get_contents($file->getRealPath());
+
+        $groups = ['simple'];
+        //Add group when the children should be preserved
+        if ($options['preserve_children']) {
+            $groups[] = 'include_children';
+        }
+
+        //The [] behind class_name denotes that we expect an array.
+        $entities = $this->serializer->deserialize($content, $class_name . '[]', $options['format'], ['groups' => $groups]);
+
+        //Ensure we have an array of entitity elements.
+        if(!is_array($entities)) {
+            $entities = [$entities];
+        }
+
+        //The serializer has only set the children attributes. We also have to change the parent value (the real value in DB)
+        if ($entities[0] instanceof StructuralDBElement) {
+            $this->correctParentEntites($entities, null);
+        }
+
+        return $entities;
+    }
+
+    /**
+     * This functions corrects the parent setting based on the children value of the parent.
+     * @param iterable $entities The list of entities that should be fixed.
+     * @param null $parent The parent, to which the entity should be set.
+     */
+    protected function correctParentEntites(iterable $entities, $parent = null)
+    {
+        foreach ($entities as $entity) {
+            /** @var $entity StructuralDBElement */
+            $entity->setParent($parent);
+            //Do the same for the children of entity
+            $this->correctParentEntites($entity->getChildren(), $entity);
+        }
+    }
+}