Expand API to return transaction groups.

app/Support/Binder/UserGroupAccount.php

@@ -0,0 +1,59 @@
+<?php
+
+/**
+ * AccountList.php
+ * Copyright (c) 2019 james@firefly-iii.org
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+declare(strict_types=1);
+
+namespace FireflyIII\Support\Binder;
+
+use FireflyIII\Models\Account;
+use FireflyIII\User;
+use Illuminate\Routing\Route;
+use Illuminate\Support\Collection;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Class UserGroupAccount.
+ */
+class UserGroupAccount implements BinderInterface
+{
+    /**
+     * @param string $value
+     * @param Route  $route
+     *
+     * @return Account
+     * @throws NotFoundHttpException
+     *
+     */
+    public static function routeBinder(string $value, Route $route): Account
+    {
+        if (auth()->check()) {
+            /** @var User $user */
+            $user     = auth()->user();
+            $currency = Account::where('id', (int)$value)
+                               ->where('user_group_id', $user->user_group_id)
+                               ->first();
+            if (null !== $currency) {
+                return $currency;
+            }
+        }
+        throw new NotFoundHttpException();
+    }
+}