1 # $Id: DocumentLocator.pm,v 1.3 2005/10/14 20:31:20 matt Exp $

     2 

     3 package XML::SAX::DocumentLocator;

     4 use strict;

     5 

     6 sub new {

     7     my $class = shift;

     8     my %object;

     9     tie %object, $class, @_;

    10 

    11     return bless \%object, $class;

    12 }

    13 

    14 sub TIEHASH {

    15     my $class = shift;

    16     my ($pubmeth, $sysmeth, $linemeth, $colmeth, $encmeth, $xmlvmeth) = @_;

    17     return bless { 

    18         pubmeth => $pubmeth,

    19         sysmeth => $sysmeth,

    20         linemeth => $linemeth,

    21         colmeth => $colmeth,

    22         encmeth => $encmeth,

    23         xmlvmeth => $xmlvmeth,

    24     }, $class;

    25 }

    26 

    27 sub FETCH {

    28     my ($self, $key) = @_;

    29     my $method;

    30     if ($key eq 'PublicId') {

    31         $method = $self->{pubmeth};

    32     }

    33     elsif ($key eq 'SystemId') {

    34         $method = $self->{sysmeth};

    35     }

    36     elsif ($key eq 'LineNumber') {

    37         $method = $self->{linemeth};

    38     }

    39     elsif ($key eq 'ColumnNumber') {

    40         $method = $self->{colmeth};

    41     }

    42     elsif ($key eq 'Encoding') {

    43         $method = $self->{encmeth};

    44     }

    45     elsif ($key eq 'XMLVersion') {

    46         $method = $self->{xmlvmeth};

    47     }

    48     if ($method) {

    49         my $value = $method->($key);

    50         return $value;

    51     }

    52     return undef;

    53 }

    54 

    55 sub EXISTS {

    56     my ($self, $key) = @_;

    57     if ($key =~ /^(PublicId|SystemId|LineNumber|ColumnNumber|Encoding|XMLVersion)$/) {

    58         return 1;

    59     }

    60     return 0;

    61 }

    62 

    63 sub STORE {

    64     my ($self, $key, $value) = @_;

    65 }

    66 

    67 sub DELETE {

    68     my ($self, $key) = @_;

    69 }

    70 

    71 sub CLEAR {

    72     my ($self) = @_;

    73 }

    74 

    75 sub FIRSTKEY {

    76     my ($self) = @_;

    77     # assignment resets.

    78     $self->{keys} = {

    79         PublicId => 1,

    80         SystemId => 1,

    81         LineNumber => 1,

    82         ColumnNumber => 1,

    83         Encoding => 1,

    84         XMLVersion => 1,

    85     };

    86     return each %{$self->{keys}};

    87 }

    88 

    89 sub NEXTKEY {

    90     my ($self, $lastkey) = @_;

    91     return each %{$self->{keys}};

    92 }

    93 

    94 1;

    95 __END__

    96 

    97 =head1 NAME

    98 

    99 XML::SAX::DocumentLocator - Helper class for document locators

   100 

   101 =head1 SYNOPSIS

   102 

   103   my $locator = XML::SAX::DocumentLocator->new(

   104       sub { $object->get_public_id },

   105       sub { $object->get_system_id },

   106       sub { $reader->current_line },

   107       sub { $reader->current_column },

   108       sub { $reader->get_encoding },

   109       sub { $reader->get_xml_version },

   110   );

   111 

   112 =head1 DESCRIPTION

   113 

   114 This module gives you a tied hash reference that calls the

   115 specified closures when asked for PublicId, SystemId,

   116 LineNumber and ColumnNumber.

   117 

   118 It is useful for writing SAX Parsers so that you don't have

   119 to constantly update the line numbers in a hash reference on

   120 the object you pass to set_document_locator(). See the source

   121 code for XML::SAX::PurePerl for a usage example.

   122 

   123 =head1 API

   124 

   125 There is only 1 method: C<new>. Simply pass it a list of

   126 closures that when called will return the PublicId, the

   127 SystemId, the LineNumber, the ColumnNumber, the Encoding 

   128 and the XMLVersion respectively.

   129 

   130 The closures are passed a single parameter, the key being

   131 requested. But you're free to ignore that.

   132 

   133 =cut

   134