How to modify $data before saving?

[anrol]

vBulletin 5.3.4 Patch Level 1
After user create new post or edit existing, i need check and modify some text in it. How can I do it? Is there hook in class vB_Api_Page to do this? What can I do to resolve my problem?

--------------- Added [DATE]1520272291[/DATE] at [TIME]1520272291[/TIME] ---------------

Anothe way, i can edit rawtext when page is fetching to client.
This my code

class myclass_Api_Page extends vB_Api_Extensions {
//....

 public function fetchPageById($page, $pageid, $routeData = array())
    {
      $nodeid = $routeData['nodeid'];
      $node = vB_Library::instance('node')->getNodeBare($nodeid);
      //...
     // but what can i do when post wil be edit? 
      return $page;
    }