added annotation based exporter (#1831)

* added user exporter
* added project exporter
* added customer exporter
* added activity exporter

src/Event/AbstractMetaDisplayEvent.php

@@ -0,0 +1,76 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Event;
+
+use App\Entity\MetaTableTypeInterface;
+use App\Repository\Query\BaseQuery;
+use Symfony\Contracts\EventDispatcher\Event;
+
+abstract class AbstractMetaDisplayEvent extends Event implements MetaDisplayEventInterface
+{
+    /**
+     * @var BaseQuery
+     */
+    private $query;
+    /**
+     * @var string
+     */
+    private $location;
+    /**
+     * @var MetaTableTypeInterface[]
+     */
+    private $fields = [];
+
+    public function __construct(BaseQuery $query, string $location)
+    {
+        $this->query = $query;
+        $this->location = $location;
+    }
+
+    /**
+     * To filter where your meta-field will be displayed, use the query settings.
+     *
+     * @return BaseQuery
+     */
+    public function getQuery(): BaseQuery
+    {
+        return $this->query;
+    }
+
+    /**
+     * If you want to filter where your meta-field will be displayed, check the current location.
+     *
+     * @return string
+     */
+    public function getLocation(): string
+    {
+        return $this->location;
+    }
+
+    /**
+     * Add a new meta field that should be included.
+     *
+     * @param MetaTableTypeInterface $meta
+     */
+    public function addField(MetaTableTypeInterface $meta)
+    {
+        $this->fields[] = $meta;
+    }
+
+    /**
+     * Returns all meta-fields to be included.
+     *
+     * @return MetaTableTypeInterface[]
+     */
+    public function getFields(): array
+    {
+        return $this->fields;
+    }
+}