Filter lookup values by current field value

Found solution myself. It doesn't shine with simplicity but it works. Here it is.
Let's say there are tables

• requests (I'm with MySQL, so change syntax accordingly) :
  
  request_id, name, whatever_column, status_id
  
• statuses:
  
  status_id, name
  
• status_rules:
  
  status_id, can_change_to_id
  The later one specifies:
  
• for existing status (status_id) how it can change (can_change_to_id) and to itself (for display purpose)
  
• for display purpose add all statuses (can_change_to_id) with status_id = 0. This entries are necessary to display status name when records are in read mode
  Add view joining all statuses with their rules:
  
  create view vw_status_rules
  
  SELECT
  
  r.status_id,
  
  r.can_change_to_id,
  
  s.Name AS Name
  
  FROM (status_rules r
  
  LEFT JOIN statuses s
  
  ON ((r.can_change_to_id = s.status_id)))
  Now it's a PHPRunner turn:
  
• Sync you project.
  
• Go to Editor, select status_id field, got to Edit as:, Lookup Wizard
  
• Select vw_status_rules in Tables
  
• Select can_change_to_id as Link field
  
• Display Name an d Order by - Name
  
• in WHERE type in " status_id = " . $_SESSION["status_id"]
  
• submit changes
  
• Go to Events
  
• Select List page -> List page: Before process. Add $_SESSION["status_id"] = '0'; to function BeforeProcessList
  
• Select Edit page -> Before Display. Add $_SESSION["status_id"] = $values['status_id']; to function BeforeShowEdit
  
• Select Edit page -> After record updated. Add $_SESSION["status_id"] = '0'; to function AfterEdit
  That's it.
  Would be glad to have more elegant solution. Let me know if you have one. <img src='https://asprunner.com/forums/file.php?topicimage=1&fieldname=reply&id=73603&image=1&table=forumreplies' class='bbc_emoticon' alt=':)' />
  
  Cheers,
  
  Greg

I was about to suggest the same idea: WHERE clause based on session variable that is getting populated in BeforeShowEdit event.