Use modulekit-ajax

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "lib/modulekit/form"]
 	path = lib/modulekit/form
 	url = https://github.com/plepe/modulekit-form.git
+[submodule "lib/modulekit/ajax"]
+	path = lib/modulekit/ajax
+	url = https://github.com/plepe/modulekit-ajax.git

ajax.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * @file ajax.php
+ * @brief Most ajax-requests call this file, it calls the specified function.
+ */
+?>
+<?php include "conf.php"; /* load a local configuration */ ?>
+<?php include "modulekit/loader.php"; /* loads all php-includes */ ?>
+<?php
+call_hooks("ajax_start");
+
+function error($msg) {
+  /// Do something with this error
+}
+
+Header("Content-Type: application/json; charset=UTF-8");
+
+$postdata = file_get_contents("php://input");
+if ($postdata) {
+  $postdata = json_decode($postdata, true);
+}
+
+$fun = "ajax_{$_REQUEST['__func']}";
+$return = $fun($_REQUEST["param"], $postdata);
+
+print json_encode($return);

lib/modulekit/ajax

@@ -0,0 +1 @@
+Subproject commit 4dec2cc1d705f45132e2e7322aec657ddb9069af

modulekit.php

@@ -5,6 +5,7 @@ $depend = array(
   'html',
   'modulekit-lang',
   'modulekit-form',
+  'modulekit-ajax',
   'openstreetbrowser-categories-main',
   'openstreetmap-tag-translations',
 );