XML::Schema::Type::Simple - base class for simple XML Schema datatypes
package XML::Schema::Type::whatever; use base qw( XML::Schema::Type::Simple ); use vars qw( @FACETS ); @FACETS = ( minLength => 10, maxLength => 30, otherFacet => { value => $n, fixed => 1, annotation => "a comment", }, ); package main; my $type = XML::Schema::Type::whatever->new() || die XML::Schema::Type::whatever->error(); my $item = $type->instance('some instance value') || die $type->error(); # NOTE: some issues still to resolve on the precise # nature and structure of instances (currently hash ref). print $item->{ value };
The XML::Schema::Type::Simple module is a base class for objects that represent XML Schema simple types.
At the moment it's cumbersome to have to manually instantiate a type object and then call instance() on it. new() should probably become class() and instance() should become new(). Calling new() as a class method should automatically generate a prototype class object via class() and call new() against that (and also cache the prototype in a package variable for future invocations).
my $pkg = 'XML::Schema::Type::string'; my $obj1 = $pkg->new(); my $class = $pkg->class(); my $obj2 = $class->new();
The only remaining issue is then which class we should bless the type instance into, if any? We don't want to bless it into the *::Type::* class because it's not a type, it's an instance. One possiblity is to degrade the type system to work only at the class/package level, i.e. types would be analogous to Perl packages. Although this might make more sense in the long run, at this point in time I suspect that there are more benefits to be had from allowing types to be living, breathing objects which can be cloned and specialised. We _could_ do this via Perl packages, but I'm wary about building lots of new Perl packages and evaling them at runtime to allow user-definable types to be created on-the-fly. Another possibility is to bless it into a corresponding *::Instance::* package. A third, and the current favourite, is to not bless it at all. Leave it as a hash and then let the caller bless it into an Element or Attribute.
Andy Wardley <abw@kfs.org>
This is version $Revision: 1.2 $ of the XML::Schema::Type::Simple, distributed with version 0.1 of the XML::Schema module set.
Copyright (C) 2001 Canon Research Centre Europe Ltd. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
See also XML::Schema and XML::Schema::Type.
To install XML::Schema, copy and paste the appropriate command in to your terminal.
cpanm
cpanm XML::Schema
CPAN shell
perl -MCPAN -e shell install XML::Schema
For more information on module installation, please visit the detailed CPAN module installation guide.