OnValidate - cWebBaseDEO

Return False to keep the focus in the current control.

Function OnValidate Returns Boolean

Fired to validate control data.

OnValidate is intended primarily for non data-aware controls. With data-aware controls, you should do the data validation in a DataDictionary class or DDO. When not augmented in your own code, OnValidate calls File_Field_Validate_Field of the DDO when the control is connected to a DDO.

Set pbServerOnValidate to True for the server side even to fire.

Set pbServerOnValidate to True

Function OnValidate Returns Boolean
    String sValue
    Boolean bRetVal
        
    Forward Get OnValidate to bRetVal
        
    WebGet psValue to sValue
    If (sValue <> "test") Begin
        Move False to bRetVal
    End
        
    Function_Return bRetVal
End_Function

Sample

This sample shows how to make sure user entry stays between 0 and 4. If the user enters a value outside that range, set it lowest or highest allowed value.

Object oProductSize is a cWebForm
    Set piColumnSpan to 3
    Set psLabel to "Size"
    Set piColumnIndex to 4
    Set peDataType to typeNumber
    Set psMask to "#.#"

    Function OnValidate Returns Boolean
        Boolean bRetVal
    
        Short siVal
    
        Forward Get OnValidate to bRetVal
        WebGet psValue to siVal
        If (siVal > 4) Begin
            WebSet psValue to 4
            Move False to bRetVal
        End
        Else If (siVal < 0) Begin
            WebSet psValue to 0
            Move False to bRetVal
        End
    
        Function_Return bRetVal
    End_Function
End_Object

Desktop vs Mobile Browser Behavior

In desktop browsers, OnValidate triggers when tabbing (forward navigating) the next form. So not every blur causes a validate. This is by design, as we don't want OnValidate to trigger when, for example, you click a toolbar item. A save will also trigger the same validation.

Mobile browsers do not support proper events to handle a click on this 'next field button' shown on many mobile keyboards. So there is no hook for us to use for OnValidate during forward navigation. Thus, on mobile browsers, OnValidate is only performed when a record is saved.

You can try using OnBlur for validation on mobile devices, but it will likely be called too often.