Expand API for attachments.

app/Rules/IsValidAttachmentModel.php

@@ -0,0 +1,88 @@
+<?php
+/**
+ * IsValidAttachmentModel.php
+ * Copyright (c) 2018 thegrumpydictator@gmail.com
+ *
+ * This file is part of Firefly III.
+ *
+ * Firefly III 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Firefly III 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 Firefly III. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace FireflyIII\Rules;
+
+
+use FireflyIII\Exceptions\FireflyException;
+use FireflyIII\Models\TransactionJournal;
+use FireflyIII\Repositories\Journal\JournalRepositoryInterface;
+use Illuminate\Contracts\Validation\Rule;
+
+/**
+ * Class IsValidAttachmentModel
+ */
+class IsValidAttachmentModel implements Rule
+{
+    /** @var string */
+    private $model;
+
+    /**
+     * IsValidAttachmentModel constructor.
+     *
+     * @param string $model
+     */
+    public function __construct(string $model)
+    {
+        $this->model = $model;
+    }
+
+    /**
+     * Get the validation error message.
+     *
+     * @return string
+     */
+    public function message(): string
+    {
+        return trans('validation.model_id_invalid');
+    }
+
+    /**
+     * Determine if the validation rule passes.
+     *
+     * @param  string $attribute
+     * @param  mixed  $value
+     *
+     * @return bool
+     * @throws FireflyException
+     */
+    public function passes($attribute, $value): bool
+    {
+        if (!auth()->check()) {
+            return false;
+        }
+        $user = auth()->user();
+        switch ($this->model) {
+            default:
+                throw new FireflyException(sprintf('Model "%s" cannot be validated.', $this->model));
+            case TransactionJournal::class:
+                /** @var JournalRepositoryInterface $repository */
+                $repository = app(JournalRepositoryInterface::class);
+                $repository->setUser($user);
+                $result     = $repository->findNull((int)$value);
+
+                return null !== $result;
+                break;
+        }
+    }
+}