company logo

PropertyHandle :: ChangeMode - Change access mode

The function allows changing the access mode for a PropertyHandle. This requires that the database object access mode is higher or equal to the mode that is going to be activated.

You can always change from higher modes (PI_Write, PI_Update) to lower modes (PI_Read). Changing from read to update or write mode has, however, some limitations. You may change the mode in any directions for extent property handles and for property handles referring to update-able relationships. Changing the mode for non update-able relationships or references, however, is possible only to PI_Read or PI_Write. Changing to PI_Write is possible only, when the parent PropertyHandle is opened with or set to PI_Write.

Changing the access mode will cancel all subsequent PropertyHandles and change the mode to the mode requested for the current PropertyHandle.

Property handle running in block mode can be accessed in read mode, only. Change mode will fail when attempting to change the mode to update or write in this case.

Return value:  Old access mode (   )

Access mode that was valid for the property handle.

Implementation details

PIACC PropertyHandle  :: ChangeMode ( PIACC newmode, logical rel_opt )
  • newmode - New access mode

    Access mode to be set for the property handle.

  • rel_opt - - internal feature (not documented)