If the XML parser encounters an anomaly or error during parsing, it sets an exception code in the XML-CODE special register and signals an XML exception event.
If the exception code is within a certain range, you might be able to handle the exception event within your processing procedure, and resume parsing.
To handle an exception in the processing procedure, follow these steps:
The exception condition no longer exists.
You can handle exceptions in this way only if the exception code that is passed in XML-CODE is within one of the following ranges, which indicates that an encoding conflict was detected:
Exception codes 1 - 49: In the processing procedure, you can do limited handling of exceptions for which the exception code is within the range 1 - 49. After an exception in this range occurs, the parser does not signal any further normal events, except the END-OF-DOCUMENT event, even if you set XML-CODE to zero before returning. If you set XML-CODE to zero, the parser continues parsing the document and signals any exceptions that it finds. (Doing so can provide a useful way to discover multiple errors in the document.)
At the end of parsing after an exception that has an exception code in the range 1 - 49, control is passed to the statement specified in the ON EXCEPTION phrase. If you did not code an ON EXCEPTION phrase, control is passed to the end of the XML PARSE statement. XML-CODE contains the code set by the parser for the most recent exception.
For all exceptions other than those having an exception code within one of the ranges described above, the parser does not signal any further events, but passes control to the statement specified in the ON EXCEPTION phrase. XML-CODE contains the original exception code even if you set XML-CODE in the processing procedure before returning control to the parser.
If you do not want to handle an exception, return control to the parser without changing the value of XML-CODE. The parser transfers control to the statement specified in the ON EXCEPTION phrase. If you did not code an ON EXCEPTION phrase, control is transferred to the end of the XML PARSE statement.
If no unhandled exceptions occur before the end of parsing, control is passed to the statement specified in the NOT ON EXCEPTION phrase. If you did not code a NOT ON EXCEPTION phrase, control is transferred to the end of the XML PARSE statement. XML-CODE contains zero.
related concepts
XML-CODE
XML input document encoding
How the XML parser handles errors
related tasks
Writing procedures to process XML
Handling encoding conflicts
related references
The encoding of XML documents
XML PARSE exceptions