Add API to add a link to an action

src/Extend/ApiLink.php

@@ -0,0 +1,28 @@
+<?php namespace Flarum\Extend;
+
+use Illuminate\Foundation\Application;
+
+class ApiLink implements ExtenderInterface
+{
+    protected $actions;
+
+    protected $relationships;
+
+    public function __construct($actions, $relationships)
+    {
+        $this->actions = $actions;
+        $this->relationships = $relationships;
+    }
+
+    public function extend(Application $app)
+    {
+        foreach ((array) $this->actions as $action) {
+            $parts = explode('.', $action);
+            $class = 'Flarum\Api\Actions\\'.ucfirst($parts[0]).'\\'.ucfirst($parts[1]).'Action';
+
+            foreach ((array) $this->relationships as $relationship) {
+                $class::$link[] = $relationship;
+            }
+        }
+    }
+}