Log In    |    Knowledge Base    |    4D Home
Tech Tip: How to return View Pro offscreen area object
PRODUCT: 4D View Pro | VERSION: 19 | PLATFORM: Mac & Win
Published On: June 20, 2022

When working with a View Pro offscreen area, the first step is create the object attributes of the offscreen area. There are 4 main attributes:

  • area - Name of offscreen area

  • autoQuit - Whether offscreen area should auto-quit

  • timeout - How many seconds it will take for offscreen area to auto-quit

  • onEvent - Callback method that executes when offscreen area is ready

  • The object containing these attributes is then passed as an argument to the method VP Run offscreen area as shown below:


    $param_o:=New object
    $param_o.area:="TestArea" // Name of VP object
    $param_o.autoQuit:=False // Boolean for autoclosing the offscreen area
    $param_o.timeout:=30 // Number of seconds before offscreen area autocloses
    $param_o.onEvent:=Formula(onEvent) // Callback method
    $offscreenResult_v:=VP Run offscreen area($param_o) // Result from callback method

    For the onEvent callback method, it will simply create a new VP document, add some text to cell 0 0, then return the offscreen area as an object as shown below:

    // Method: onEvent

    Case of
       : (Form event code =On VP Ready)
       // Create new document
       VP NEW DOCUMENT(This.area)
       // Modifying new document by editting cell 0 0
       $range_o:=VP Cell(This.area; 0; 0)
       VP SET TEXT VALUE($range_o; "This is cell 0 0")
       // Export object to result
       This.result:=VP Export to object(This.area)
    End case

    The VP object is now returned in the local variable $offscreenResult_v which can now be used to display on a form's View Pro area if needed using VP IMPORT FROM OBJECT.

    // Import offscreen result object to form's "ViewProArea"
    VP IMPORT FROM OBJECT("ViewProArea"; $offscreenResult_v)