Worked on the saving api method.

cal/api.php

@@ -2,7 +2,11 @@
 header("Content-Type: application/json");
 include('lib.php');
 $ret = array( "err" => "unknown command" );
-if ( $_GET["cmd"] == "get" ) {
+if ( in_array("cmd", array_keys($_GET)) and $_GET["cmd"] == "get" ) {
+  $ret = getEvents();
+} elseif ( $_POST["cmd"] == "put" ) {
+  $json = base64_decode($_POST["payload"]);
+  file_put_contents("dat/events.json", $json);
   $ret = getEvents();
 }
 print(json_encode($ret));