Add external links for tasks with plugin api

app/ExternalLink/BaseLinkProvider.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Kanboard\ExternalLink;
+
+use Kanboard\Core\Base;
+
+/**
+ * Base Link Provider
+ *
+ * @package  externalLink
+ * @author   Frederic Guillot
+ */
+abstract class BaseLinkProvider extends Base
+{
+    /**
+     * User input
+     *
+     * @access protected
+     * @var string
+     */
+    protected $userInput = '';
+
+    /**
+     * Set text entered by the user
+     *
+     * @access public
+     * @param  string $input
+     */
+    public function setUserTextInput($input)
+    {
+        $this->userInput = trim($input);
+    }
+}