1 #

     2 # Use XML::DOM::ValParser instead of XML::DOM::Parser and it will

     3 # use XML::Checker to validate XML at parse time.

     4 #

     5 

     6 package XML::DOM::ValParser;

     7 

     8 use strict;

     9 use XML::DOM;

    10 use XML::Checker::Parser;

    11 

    12 use vars qw( @ISA @SupportedHandlers );

    13 

    14 @ISA = qw( XML::Checker::Parser );

    15 

    16 # These XML::Parser handlers are currently supported by XML::DOM

    17 @SupportedHandlers = qw( Init Final Char Start End Default Doctype

    18 			 CdataStart CdataEnd XMLDecl Entity Notation Proc 

    19 			 Default Comment Attlist Element Unparsed );

    20 

    21 sub new

    22 {

    23     my ($class, %args) = @_;

    24     

    25     my %handlers = ();

    26     for (@SupportedHandlers)

    27     {

    28 	my $domHandler = "XML::Parser::Dom::$_";

    29 	$handlers{$_} = \&$domHandler;

    30     }

    31     $args{Handlers} = \%handlers;

    32     $class->SUPER::new (%args);

    33 }

    34 

    35 sub parse

    36 {

    37     # Do what XML::DOM::Parser normally does.

    38     # Temporarily override his @ISA, so that he thinks he's a

    39     # XML::DOM::ValParser and calls the right SUPER::parse(),

    40     # (otherwise he thinks he's an XML::DOM::Parser and you see runtime

    41     #  error: Can't call method "Init" on unblessed reference ...)

    42     local @XML::DOM::Parser::ISA = @ISA;

    43     local $XML::Checker::Parser::_skipInsignifWS = $_[0]->{SkipInsignifWS};

    44     XML::DOM::Parser::parse (@_);

    45 }

    46 

    47 1; # package return code

    48 

    49 __END__

    50 

    51 =head1 NAME

    52 

    53 XML::DOM::ValParser - an XML::DOM::Parser that validates at parse time

    54 

    55 =head1 SYNOPSIS

    56 

    57  use XML::DOM::ValParser;

    58 

    59  my %expat_options = (KeepCDATA => 1, 

    60 		      Handlers => [ Unparsed => \&my_Unparsed_handler ]);

    61  my $parser = new XML::DOM::ValParser (%expat_options);

    62 

    63  eval {

    64      local $XML::Checker::FAIL = \&my_fail;

    65      my $doc = $parser->parsefile ("fail.xml");

    66      ... XML::DOM::Document was created sucessfully ...

    67  };

    68  if ($@) {

    69      # Either XML::Parser (expat) threw an exception or my_fail() died.

    70      ... your error handling code here ...

    71      # Note that the XML::DOM::Document is automatically disposed off and

    72      # will be garbage collected

    73  }

    74 

    75  # Throws an exception (with die) when an error is encountered, this

    76  # will stop the parsing process.

    77  # Don't die if a warning or info message is encountered, just print a message.

    78  sub my_fail {

    79      my $code = shift;

    80      die XML::Checker::error_string ($code, @_) if $code < 200;

    81      XML::Checker::print_error ($code, @_);

    82  }

    83 

    84 =head1 DESCRIPTION

    85 

    86 Use XML::DOM::ValParser wherever you would use L<XML::DOM::Parser> and

    87 your XML will be checked using L<XML::Checker> at parse time.

    88 

    89 See L<XML::DOM> for details on XML::DOM::Parser options.

    90 See L<XML::Checker> for details on setting the fail handler (my_fail.)

    91 

    92 The following handlers are currently supported, just like XML::DOM::Parser:

    93 Init, Final, Char, Start, End, Default, Doctype, CdataStart, CdataEnd, 

    94 XMLDecl, Entity, Notation, Proc, Default, Comment, Attlist, Element, Unparsed.

    95 

    96 =head1 XML::DOM::ValParser

    97 

    98 XML::DOM::ValParser extends from L<XML::Checker::Parser>. It creates an

    99 L<XML::Checker> object and routes all event handlers through the checker,

   100 before processing the events to create the XML::DOM::Document.

   101 

   102 Just like L<XML::Checker::Parser>, the checker object can be retrieved with

   103 the getChecker() method and can be reused later on (provided that the DOCTYPE

   104 section of the XML::DOM::Document did not change in the mean time.)

   105 

   106 You can control which errors are fatal (and therefore should stop creation

   107 of the XML::DOM::Document) by filtering the appropriate error codes in

   108 the global $XML::Checker::FAIL handler 

   109 (see L<XML::Checker/ERROR_HANDLING>) and 

   110 calling I<die> or I<croak> appropriately.

   111 

   112 Just like XML::Checker::Parser, XML::DOM::ValParser supports the 

   113 SkipExternalDTD and SkipInsignifWS options. See L<XML::Checker::Parser>

   114 for details.

   115 

   116 =head1 AUTHOR

   117 

   118 Send bug reports, hints, tips, suggestions to Enno Derksen at

   119 <F<enno@att.com>>.

   120 

   121 =head1 SEE ALSO

   122 

   123 L<XML::DOM>, L<XML::Checker> (L<XML::Checker/SEE_ALSO>)