ABL SAX callbacks

When the XML parser encounters an XML token, ABL invokes the callback corresponding to that token—if that callback is provided by the developer. If not, the parser continues.

ABL SAX implements callbacks as internal procedures coded by the ABL developer using signatures specified by ABL. Normally, callbacks are placed in a procedure (.p) file that the application runs persistently. But callbacks can also be placed in the driver routine. A driver routine is one that calls the SAX-PARSE( ) or SAX-PARSE-FIRST( ) method. In either case, your application assigns the containing procedure's handle to the SAX-reader HANDLER attribute. (The HANDLER attribute defaults to a handle to the driver routine). Then, the application starts the parse.

Within a callback, to get a handle to the SAX-reader object that invoked the callback, use the SELF system handle.

The following fragment uses SELF within a callback to call the SAX-reader STOP-PARSING( ) method:

SELF:STOP-PARSING( ).

The following fragment uses SELF within a callback to store data in the SAX-reader PRIVATE-DATA attribute:

SELF:PRIVATE-DATA = "xyz123".

For information on the SAX parser's current location in the XML source, use the following attributes of SAX-reader:

• LOCATOR-COLUMN-NUMBER
• LOCATOR-LINE-NUMBER
• LOCATOR-PUBLIC-ID
• LOCATOR-SYSTEM-ID

The following table summarizes the ABL SAX callbacks. For a complete description, see SAX callback reference.