Application Techniques
Using PowerBuilder XML Services

PBDOM defines an exception class, PBDOM_EXCEPTION, derived from the standard PowerBuilder Exception class. The standard Text property of the Exception class can be used to obtain more detail on the nature of the exception being thrown. The class extends the PowerBuilder Exception class with one method, GetExceptionCode, that returns the unique code that identifies the exception being thrown.

For a list of exception codes, see the section called “PBDOM exceptions” in PowerBuilder Extension Reference or the section called “Handling PBDOM exceptions”.

PBDOM is a PowerBuilder extension, built using PBNI. The extension itself might throw a PBXRuntimeError exception. In the following example, the try-catch block checks first for a PBDOM exception, then for a PBXRuntimeError.

The example builds a PBDOM_DOCUMENT from a passed-in file name and uses a user-defined function called ProcessData to handle the DOM nodes. ProcessData could be a recursive function that extracts information from the DOM elements for further processing:

Long ll_ret

ll_ret = XMLParseFile(filename, ValNever!)
if ll_ret < 0 then return

PBDOM_Builder   domBuilder

TRY
   domBuilder = CREATE PBDOM_Builder
   PBDOM_Document domDoc
   PBDOM_Element   root
   domDoc = domBuilder.BuildFromFile( filename )
   IF IsValid( domDoc ) THEN
      IF domDoc.HasChildren() THEN
         PBDOM_Object data[]
         IF domDoc.GetContent( data ) THEN
            Long   ll_index, ll_count
            ll_count = UpperBound( data )
            FOR ll_index = 1 TO ll_count
               ProcessData( data[ll_index], 0 )
            NEXT
         END IF
      END IF
   END IF

CATCH ( PBDOM_Exception pbde )
   MessageBox( "PBDOM Exception", pbde.getMessage() )
CATCH ( PBXRuntimeError re )
   MessageBox( "PBNI Exception", re.getMessage() )
END TRY