<< Click to Display Table of Contents >> Navigation:  Examples > Other samples > Other 3: Events

This sample is designed to show you some of the recordset and connection events.

It implements two event handlers:

•MyConnectionEvents

•MyRecordSetEvents.

The only thing the methods of these event handlers do is to show that they are being called and to show their parameters like you can see below:

 

METHOD BeginTransComplete(lTransactionLevel , oError , lStatus , ;

 oConnection) CLASS MyConnectionEvents

 WriteLog( "BeginTrans", lTransactionLevel , lStatus , oConnection)

 

METHOD FieldChangeComplete (nFields , uFields , oError, lStatus, ;

 oRecordSet) CLASS MyRecordSetEvents

 WriteLog( "FieldChangeComplete", nFields , uFields , lStatus, oRecordSet)

 IF IsArray(uFields)

         AEval(uFields, {|oFld|WriteLog(" > Field", ;

         oFld:Name, OFld:Value, OFld:OriginalValue)})                

 ENDIF

 

The WriteLog() function write the results to the console and to a logfile.

The main program shows how to open a connection Asynchronous and Synchronous:

 

 oConn := AdoConnection{}

 AdoSetConnection(oConn)

 oConnEvents := MyConnectionEvents{}

 oConn:EnableEvents(oConnEvents)

 // Set the connection for better error reports

 WriteLog("ASynchronous open")

 AdoSetConnection(oConn)

 oConn:CursorLocation := adUseClient

 oConn:Open(strCnn,NIL,NIL,adAsyncConnect )

 DO WHILE oCOnn:State != adStateOPen

         WriteLog("Connecting...")

         Sleep(10)

 ENDDO

 oConn:Close()

 WriteLog("Now normal Synchronous open")

 oCOns:WriteLine("Enter to continue")

 oCOns:Read()

 oConn:Open(strCnn,NIL,NIL,NIL)

 

It also shows how to display the fetch progress of a recordset:

 

 oRstEvents := MyRecordSetEvents {}

 oRs:EnableEvents(oRstEvents)

 oRs:CursorLocation := AdUseClient

 oRs:Properties:[Item,"Initial Fetch Size"]:Value := 0

 oRs:Properties:[Item,"Background Fetch Size"]:Value := 5

 WriteLog("The recordset is opened. " )

 WriteLog("A fetchprogress will be called on ANOTHER THREAD for every 5 rows")

 oCons:WriteLine("Enter to continue")

 oCOns:Read()

 oRs:Open("employee",oConn,adOpenKeySet,AdLockOptimistic,adCmdTable+AdAsyncFetch)

 DO WHILE oRs:State != AdStateOpen .and. oRs:State <> AdStateClosed

         WriteLog("Fetching")

         Sleep(5)

 ENDDO

 

Please note that this will cause a second thread to be started. Be very careful with what you do in the second thread. Accessing GUI objects will certainly cause runtime errors, since the X# GUI classes are NOT threadsafe !