Oracle® Objects for OLE C++ Class Library Developer's Guide 10g Release 2 (10.2) Part Number B14308-01 |
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Applies To
Description
The ActionRequest method is called by a dynaset when that dynaset is about to start an operation. You do not call ActionRequest; the ActionRequest method of your OAdvise subclass is called by the dynaset.
Usage
oboolean ActionRequest(int actiontype)
Arguments
actiontype will have one of the following values:
Value |
Description |
---|---|
OADVISE_MOVE_FIRST |
// dynaset moving to first record |
OADVISE_MOVE_PREV |
// dynaset moving to previous record |
OADVISE_MOVE_NEXT |
// dynaset moving to next record |
OADVISE_MOVE_LAST |
// dynaset moving to last record |
OADVISE_MOVE_TOMARK |
// dynaset moving to dynaset mark |
OADVISE_REFRESH |
// dynaset refreshing |
OADVISE_DELETE |
// dynaset deleting current record |
OADVISE_ADDNEW |
// dynaset adding a new record |
OADVISE_UPDATE |
// dynaset updating |
OADVISE_ROLLBACK |
// session (that dynaset is part of) is rolling back |
When you subclass OAdvise, you can override the ActionRequest method. After an instance of your OAdvise subclass is attached to a dynaset (by way of the OAdvise::Open method), your instance receives calls to its ActionRequest method. Use an ActionRequest method to control whether certain dynaset actions should be allowed to proceed, or to do your own processing before dynaset actions occur.
The unoverridden ActionRequest method of OAdvise always returns TRUE, allowing all dynaset operations to proceed immediately.
Return value
TRUE - tells the dynaset that the action can proceed
FALSE - tells the dynaset to cancel the action
Example
This example attempts to save a change to the current record if there is one. This is an action that needs to be taken before the dynaset does an operation.
oboolean YourOAdvise::ActionRequest(int actiontype) { // check whether we have an unsaved change in this record int error; if (m_havechange) { // we have a change, try to save it error = m_context->SaveTheChange(); if (error != 0) { // some problem - cancel the action return(FALSE); } } // everything is fine, allow the action return(TRUE); }