First basic code for currency exchange rate routines.

app/Support/Binder/CurrencyCode.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * CurrencyCode.php
+ * Copyright (c) 2017 thegrumpydictator@gmail.com
+ * This software may be modified and distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International License.
+ *
+ * See the LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace FireflyIII\Support\Binder;
+
+use FireflyIII\Models\TransactionCurrency;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Class CurrencyCode
+ *
+ * @package FireflyIII\Support\Binder
+ */
+class CurrencyCode implements BinderInterface
+{
+
+    /**
+     * @param $value
+     * @param $route
+     *
+     * @return mixed
+     */
+    public static function routeBinder($value, $route)
+    {
+        $currency = TransactionCurrency::where('code', $value)->first();
+        if (!is_null($currency)) {
+            return $currency;
+        }
+        throw new NotFoundHttpException;
+    }
+}