CATALOG() | Hackers Guide to Visual FoxPro 7.0

BeforeModifyConnection, AfterModifyConnection

These database events fire when a connection is modified in the Connection Designer.

Usage

PROCEDURE DBC_BeforeModifyConnection( cConnectionName )   PROCEDURE DBC_AfterModifyConnection( cConnectionName, lChanged )

Parameter	Value	Meaning
cConnectionName	Character	The name of the connection.
lChanged	Logical	Indicates whether the connection was changed.

As is the case with other before-and-after pairs of events, you can prevent a connection from being modified (the Connection Designer won't appear) by returning .F. in the BeforeModifyConnection event, while the AfterModifyConnection event simply receives notification that something happened.

Like other connection-related events, VFP refuses to execute the method of an object in these events when they're fired visually (that is, when you choose Connections from the Database menu to display the Connections dialog and then click Modify). For example, suppose you have code like the following:

PROCEDURE DBC_BeforeModifyConnection(cConnectionName) loObject = NEWOBJECT('MyClass', 'MyLibrary.VCX') loObject.SomeMethod()

If you trace this code, you'll see the object being instantiated, but the call to SomeMethod is skipped over as if it were a comment line.

Example

* This goes in the stored procedures of a database.   PROCEDURE DBC_BeforeModifyConnection(cConnectionName) WAIT WINDOW PROGRAM() + CHR(13) + ;     'cConnectionName: ' + cConnectionName   PROCEDURE DBC_AfterModifyConnection(cConnectionName, lChanged) WAIT WINDOW PROGRAM() + CHR(13) + ;     'cConnectionName: ' + cConnectionName + CHR(13) + ;     'lChanged: ' + TRANSFORM(lChanged)   * End of stored procedures.     * Create a connection, and then modify it.   CREATE CONNECTION TestConnection DATASOURCE TasTrade MODIFY CONNECTION TestConnection