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XML::SAX::EventMethodMaker.3pm

NAME

XML::SAX::EventMethodMaker - SAX event names, creation of methods from templates

SYNOPSIS

     use XML::SAX::EventMethodMaker qw(
         sax_event_names missing_methods compile_methods
     );
 
   ## Getting event names by handler type and SAX version
     my @events          = sax_event_names;
     my @dtd_events      = sax_event_names "DTDHandler";
     my @sax1_events     = sax_event_names 1;
     my @sax1_dtd_events = sax_event_names 1, "DTDHandler";
 
   ## Figuring out what events a class or object does not provide
     my @missing = missing_methods $class, @events ;
 
   ## Creating all SAX event methods
     compile_methods $class, <<'TEMPLATE_END', sax_event_names;
     sub <EVENT> {
         my $self = shift;
         ... do something ...
 
         ## Pass the event up to the base class
         $self->SUPER::<EVENT>( @_ );
     }
     TEMPLATE_END
 
   ## Creating some methods
     compile_methods $class, <<'TEMPLATE_END', @method_names;
     ...
     TEMPLATE_END
 
   ## Creating only missing event handlers
     compile_missing_methods $class, <<'TEMPLATE_END';
     ...
     TEMPLATE_END
 
 

DESCRIPTION

In building SAX machines, it is often handle to build a set of event handlers from a common template. This helper library (or class) provides the database of handler names, queryable by type, and

Functions

sax_event_names

     my @names = sax_event_names @query_terms;
 
 

Takes a list of query terms and returns all matching events.

Query terms may be:
    - a SAX version number: 1 or 2 (no floating point or ranges)
    - Handler
    - DTDHandler
    - ContentHandler
    - DocumentHandler
    - DeclHandler
    - ErrorHandler
    - EntityResolver
    - LexicalHandler

In addition to normal SAX events, there are also ``parse'' events:
    - ParseMethods

Unrecognized query terms cause exceptions.

If no query terms are provided, then all event names from all versions are returned except for parse methods (parse, parse_uri, ...).

If any version numbers are supplied, then only events from those version numbers are returned. No support for noninteger version numbers is provided, nor for ranges. So far, only two SAX versions exist in Perl, 1 and 2.

If any handler types are provided, then only events of those types are returned. Handler types are case insensitive.

In other words, all returned events must match both a version number and a handler type.

No support for boolean logic is provided.

missing_methods

     my @missing = missing_methods __PACKAGE__, @event_names;
     my @missing = missing_methods $object, @event_names;
 
 

This subroutine looks to see if the object or class has declared event handler methods for the named events. Any events that haven't been declared are returned.

It is sufficient to use subroutine prototypes to prevent shimming AUTOLOADed (or otherwise lazily compiled) methods:

     sub start_document ;
 
 

compile_methods

     compile_methods __PACKAGE__, $template, @method_names;
     compile_methods $object,     $template, @method_names;
 
 

Compiles the given template for each given event name, substituting the event name for the string <EVENT> or <METHOD> in the template. There is no difference between these two tags, they are provided to only to let you make your templates more readable to you.

compile_missing_methods

     compile_missing_methods __PACKAGE__, $template, @method_names;
     compile_missing_methods $objects,    $template, @method_names;
 
 

Shorthand for calls like

     compile_methods __PACKAGE__, $template,
         missing_methods __PACKAGE__, @method_names;
 
 

Due Credit

The database of handlers by type was developed by Kip Hampton, modified by Robin Berjon, and pilfered and corrupted by me.

LICENSE

     Database Copyright 2002, Barrie Slaymaker, Kip Hampton, Robin Berjon
     Code Copyright 2002, Barrie Slaymaker <barries@slaysys.com>
 
 

You may use this under the terms of the Artistic, GNU Public, or BSD licences, as you see fit.