New binder for category lists.

app/Support/Binder/CategoryList.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * CategoryList.php
+ * Copyright (C) 2016 Sander Dorigo
+ *
+ * This software may be modified and distributed under the terms
+ * of the MIT license.  See the LICENSE file for details.
+ */
+
+namespace FireflyIII\Support\Binder;
+
+use Auth;
+use FireflyIII\Models\Category;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Class CategoryList
+ *
+ * @package FireflyIII\Support\Binder
+ */
+class CategoryList implements BinderInterface
+
+{
+
+    /**
+     * @param $value
+     * @param $route
+     *
+     * @return mixed
+     */
+    public static function routeBinder($value, $route)
+    {
+        if (Auth::check()) {
+            $ids = explode(',', $value);
+            /** @var \Illuminate\Support\Collection $object */
+            $object = Category::whereIn('id', $ids)
+                              ->where('user_id', Auth::user()->id)
+                              ->get();
+
+            // add empty budget if applicable.
+            if (in_array('0', $ids)) {
+                $object->push(new Category);
+            }
+
+            if ($object->count() > 0) {
+                return $object;
+            }
+        }
+        throw new NotFoundHttpException;
+    }
+}