# $Id: Makefile.PL,v 1.1.1.1 2004/05/20 17:59:56 jpetri Exp $ use strict; use ExtUtils::MakeMaker; use File::Spec; # create Base.pm first build_xml_sax_base(); build_xml_sax_exception(); WriteMakefile( 'NAME' => 'XML::SAX::Base', 'VERSION_FROM' => 'lib/XML/SAX/Base.pm', # finds $VERSION ); sub build_xml_sax_base { my $code = <<'EOHEADER'; package XML::SAX::Base; # version 0.10 - Kip Hampton # version 0.13 - Robin Berjon # version 0.15 - Kip Hampton # version 0.17 - Kip Hampton # version 0.19 - Kip Hampton # version 0.21 - Kip Hampton # version 0.22 - Robin Berjon # version 0.23 - Matt Sergeant # version 0.24 - Robin Berjon # version 0.25 - Kip Hampton # version 1.00 - Kip Hampton # version 1.01 - Kip Hampton # version 1.02 - Robin Berjon # version 1.03 - Matt Sergeant # version 1.04 - Kip Hampton #-----------------------------------------------------# # STOP!!!!! # # This file is generated by the 'Makefile.PL' file # that ships with the XML::SAX distribution. # If you need to make changes, patch that file NOT # this one. #-----------------------------------------------------# use strict; use vars qw($VERSION); use XML::SAX::Exception qw(); $VERSION = '1.04'; EOHEADER my %EVENT_SPEC = ( start_document => [qw(ContentHandler DocumentHandler Handler)], end_document => [qw(ContentHandler DocumentHandler Handler)], start_element => [qw(ContentHandler DocumentHandler Handler)], end_element => [qw(ContentHandler DocumentHandler Handler)], characters => [qw(ContentHandler DocumentHandler Handler)], processing_instruction => [qw(ContentHandler DocumentHandler Handler)], ignorable_whitespace => [qw(ContentHandler DocumentHandler Handler)], set_document_locator => [qw(ContentHandler DocumentHandler Handler)], start_prefix_mapping => [qw(ContentHandler Handler)], end_prefix_mapping => [qw(ContentHandler Handler)], skipped_entity => [qw(ContentHandler Handler)], start_cdata => [qw(DocumentHandler LexicalHandler Handler)], end_cdata => [qw(DocumentHandler LexicalHandler Handler)], comment => [qw(DocumentHandler LexicalHandler Handler)], entity_reference => [qw(DocumentHandler Handler)], notation_decl => [qw(DTDHandler Handler)], unparsed_entity_decl => [qw(DTDHandler Handler)], element_decl => [qw(DeclHandler Handler)], attlist_decl => [qw(DTDHandler Handler)], doctype_decl => [qw(DTDHandler Handler)], xml_decl => [qw(DTDHandler Handler)], entity_decl => [qw(DTDHandler Handler)], attribute_decl => [qw(DeclHandler Handler)], internal_entity_decl => [qw(DeclHandler Handler)], external_entity_decl => [qw(DeclHandler Handler)], resolve_entity => [qw(EntityResolver Handler)], start_dtd => [qw(LexicalHandler Handler)], end_dtd => [qw(LexicalHandler Handler)], start_entity => [qw(LexicalHandler Handler)], end_entity => [qw(LexicalHandler Handler)], warning => [qw(ErrorHandler Handler)], error => [qw(ErrorHandler Handler)], fatal_error => [qw(ErrorHandler Handler)], ); for my $ev (keys %EVENT_SPEC) { $code .= <<" EOTOPCODE"; sub $ev { my \$self = shift; if (defined \$self->{Methods}->{'$ev'}) { \$self->{Methods}->{'$ev'}->(\@_); } else { my \$method; my \$callbacks; if (exists \$self->{ParseOptions}) { \$callbacks = \$self->{ParseOptions}; } else { \$callbacks = \$self; } if (0) { # dummy to make elsif's below compile } EOTOPCODE my ($can_string, $aload_string); for my $h (@{$EVENT_SPEC{$ev}}) { $can_string .= <<" EOCANBLOCK"; elsif (defined \$callbacks->{'$h'} and \$method = \$callbacks->{'$h'}->can('$ev') ) { my \$handler = \$callbacks->{'$h'}; \$self->{Methods}->{'$ev'} = sub { \$method->(\$handler, \@_) }; return \$method->(\$handler, \@_); } EOCANBLOCK $aload_string .= <<" EOALOADBLOCK"; elsif (defined \$callbacks->{'$h'} and \$callbacks->{'$h'}->can('AUTOLOAD') ) { my \$res = eval { \$callbacks->{'$h'}->$ev(\@_) }; if (\$@) { die \$@; } else { # I think there's a buggette here... # if the first call throws an exception, we don't set it up right. # Not fatal, but we might want to address it. my \$handler = \$callbacks->{'$h'}; \$self->{Methods}->{'$ev'} = sub { \$handler->$ev(\@_) }; } return \$res; } EOALOADBLOCK } $code .= $can_string . $aload_string; $code .= <<" EOFALLTHROUGH"; else { \$self->{Methods}->{'$ev'} = sub { }; } } EOFALLTHROUGH $code .= "\n}\n\n"; } $code .= <<'BODY'; #-------------------------------------------------------------------# # Class->new(%options) #-------------------------------------------------------------------# sub new { my $proto = shift; my $class = ref($proto) || $proto; my $options = ($#_ == 0) ? shift : { @_ }; unless ( defined( $options->{Handler} ) or defined( $options->{ContentHandler} ) or defined( $options->{DTDHandler} ) or defined( $options->{DocumentHandler} ) or defined( $options->{LexicalHandler} ) or defined( $options->{ErrorHandler} ) or defined( $options->{DeclHandler} ) ) { $options->{Handler} = XML::SAX::Base::NoHandler->new; } my $self = bless $options, $class; # turn NS processing on by default $self->set_feature('http://xml.org/sax/features/namespaces', 1); return $self; } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # $p->parse(%options) #-------------------------------------------------------------------# sub parse { my $self = shift; my $parse_options = $self->get_options(@_); local $self->{ParseOptions} = $parse_options; if ($self->{Parent}) { # calling parse on a filter for some reason return $self->{Parent}->parse($parse_options); } else { my $method; if (defined $parse_options->{Source}{CharacterStream} and $method = $self->can('_parse_characterstream')) { warn("parse charstream???\n"); return $method->($self, $parse_options->{Source}{CharacterStream}); } elsif (defined $parse_options->{Source}{ByteStream} and $method = $self->can('_parse_bytestream')) { return $method->($self, $parse_options->{Source}{ByteStream}); } elsif (defined $parse_options->{Source}{String} and $method = $self->can('_parse_string')) { return $method->($self, $parse_options->{Source}{String}); } elsif (defined $parse_options->{Source}{SystemId} and $method = $self->can('_parse_systemid')) { return $method->($self, $parse_options->{Source}{SystemId}); } else { die "No _parse_* routine defined on this driver (if it a filter, remember to set the Parent property) [$self]"; } } } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # $p->parse_file(%options) #-------------------------------------------------------------------# sub parse_file { my $self = shift; my $file = shift; my $parse_options = $self->get_options(@_); $parse_options->{Source}{ByteStream} = $file; return $self->parse($parse_options); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # $p->parse_uri(%options) #-------------------------------------------------------------------# sub parse_uri { my $self = shift; my $file = shift; my $parse_options = $self->get_options(@_); $parse_options->{Source}{SystemId} = $file; return $self->parse($parse_options); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # $p->parse_string(%options) #-------------------------------------------------------------------# sub parse_string { my $self = shift; my $string = shift; my $parse_options = $self->get_options(@_); $parse_options->{Source}{String} = $string; return $self->parse($parse_options); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # get_options #-------------------------------------------------------------------# sub get_options { my $self = shift; if (@_ == 1) { return { %$self, %{$_[0]} }; } else { return { %$self, @_ }; } } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # get_features #-------------------------------------------------------------------# sub get_features { return ( 'http://xml.org/sax/features/external-general-entities' => undef, 'http://xml.org/sax/features/external-parameter-entities' => undef, 'http://xml.org/sax/features/is-standalone' => undef, 'http://xml.org/sax/features/lexical-handler' => undef, 'http://xml.org/sax/features/parameter-entities' => undef, 'http://xml.org/sax/features/namespaces' => 1, 'http://xml.org/sax/features/namespace-prefixes' => 0, 'http://xml.org/sax/features/string-interning' => undef, 'http://xml.org/sax/features/use-attributes2' => undef, 'http://xml.org/sax/features/use-locator2' => undef, 'http://xml.org/sax/features/validation' => undef, 'http://xml.org/sax/properties/dom-node' => undef, 'http://xml.org/sax/properties/xml-string' => undef, ); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # get_feature #-------------------------------------------------------------------# sub get_feature { my $self = shift; my $feat = shift; # check %FEATURES to see if it's there, and return it if so # throw XML::SAX::Exception::NotRecognized if it's not there # throw XML::SAX::Exception::NotSupported if it's there but we # don't support it my %features = $self->get_features(); if (exists $features{$feat}) { my %supported = map { $_ => 1 } $self->supported_features(); if ($supported{$feat}) { return $self->{__PACKAGE__ . "::Features"}{$feat}; } throw XML::SAX::Exception::NotSupported( Message => "The feature '$feat' is not supported by " . ref($self), Exception => undef, ); } throw XML::SAX::Exception::NotRecognized( Message => "The feature '$feat' is not recognized by " . ref($self), Exception => undef, ); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # set_feature #-------------------------------------------------------------------# sub set_feature { my $self = shift; my $feat = shift; my $value = shift; # check %FEATURES to see if it's there, and set it if so # throw XML::SAX::Exception::NotRecognized if it's not there # throw XML::SAX::Exception::NotSupported if it's there but we # don't support it my %features = $self->get_features(); if (exists $features{$feat}) { my %supported = map { $_ => 1 } $self->supported_features(); if ($supported{$feat}) { return $self->{__PACKAGE__ . "::Features"}{$feat} = $value; } throw XML::SAX::Exception::NotSupported( Message => "The feature '$feat' is not supported by " . ref($self), Exception => undef, ); } throw XML::SAX::Exception::NotRecognized( Message => "The feature '$feat' is not recognized by " . ref($self), Exception => undef, ); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # get_handler and friends #-------------------------------------------------------------------# sub get_handler { my $self = shift; my $handler_type = shift; $handler_type ||= 'Handler'; return defined( $self->{$handler_type} ) ? $self->{$handler_type} : undef; } sub get_document_handler { my $self = shift; return $self->get_handler('DocumentHandler', @_); } sub get_content_handler { my $self = shift; return $self->get_handler('ContentHandler', @_); } sub get_dtd_handler { my $self = shift; return $self->get_handler('DTDHandler', @_); } sub get_lexical_handler { my $self = shift; return $self->get_handler('LexicalHandler', @_); } sub get_decl_handler { my $self = shift; return $self->get_handler('DeclHandler', @_); } sub get_error_handler { my $self = shift; return $self->get_handler('ErrorHandler', @_); } sub get_entity_resolver { my $self = shift; return $self->get_handler('EntityResolver', @_); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # set_handler and friends #-------------------------------------------------------------------# sub set_handler { my $self = shift; my ($new_handler, $handler_type) = reverse @_; $handler_type ||= 'Handler'; $self->{Methods} = {} if $self->{Methods}; $self->{$handler_type} = $new_handler; return 1; } sub set_document_handler { my $self = shift; return $self->set_handler('DocumentHandler', @_); } sub set_content_handler { my $self = shift; return $self->set_handler('ContentHandler', @_); } sub set_dtd_handler { my $self = shift; return $self->set_handler('DTDHandler', @_); } sub set_lexical_handler { my $self = shift; return $self->set_handler('LexicalHandler', @_); } sub set_decl_handler { my $self = shift; return $self->set_handler('DeclHandler', @_); } sub set_error_handler { my $self = shift; return $self->set_handler('ErrorHandler', @_); } sub set_entity_resolver { my $self = shift; return $self->set_handler('EntityResolver', @_); } #-------------------------------------------------------------------# #-------------------------------------------------------------------# # supported_features #-------------------------------------------------------------------# sub supported_features { my $self = shift; # Only namespaces are required by all parsers return ( 'http://xml.org/sax/features/namespaces', ); } #-------------------------------------------------------------------# sub no_op { # this space intentionally blank } package XML::SAX::Base::NoHandler; # we need a fake handler that doesn't implement anything, this # simplifies the code a lot (though given the recent changes, # it may be better to do without) sub new { #warn "no handler called\n"; return bless {}; } 1; BODY $code .= "__END__\n"; $code .= <<'FOOTER'; =head1 NAME XML::SAX::Base - Base class SAX Drivers and Filters =head1 SYNOPSIS package MyFilter; use XML::SAX::Base; @ISA = ('XML::SAX::Base'); =head1 DESCRIPTION This module has a very simple task - to be a base class for PerlSAX drivers and filters. It's default behaviour is to pass the input directly to the output unchanged. It can be useful to use this module as a base class so you don't have to, for example, implement the characters() callback. The main advantages that it provides are easy dispatching of events the right way (ie it takes care for you of checking that the handler has implemented that method, or has defined an AUTOLOAD), and the guarantee that filters will pass along events that they aren't implementing to handlers downstream that might nevertheless be interested in them. =head1 WRITING SAX DRIVERS AND FILTERS Writing SAX Filters is tremendously easy: all you need to do is inherit from this module, and define the events you want to handle. A more detailed explanation can be found at http://www.xml.com/pub/a/2001/10/10/sax-filters.html. Writing Drivers is equally simple. The one thing you need to pay attention to is B to call events yourself (this applies to Filters as well). For instance: package MyFilter; use base qw(XML::SAX::Base); sub start_element { my $self = shift; my $data = shift; # do something $self->{Handler}->start_element($data); # BAD } The above example works well as precisely that: an example. But it has several faults: 1) it doesn't test to see whether the handler defines start_element. Perhaps it doesn't want to see that event, in which case you shouldn't throw it (otherwise it'll die). 2) it doesn't check ContentHandler and then Handler (ie it doesn't look to see that the user hasn't requested events on a specific handler, and if not on the default one), 3) if it did check all that, not only would the code be cumbersome (see this module's source to get an idea) but it would also probably have to check for a DocumentHandler (in case this were SAX1) and for AUTOLOADs potentially defined in all these packages. As you can tell, that would be fairly painful. Instead of going through that, simply remember to use code similar to the following instead: package MyFilter; use base qw(XML::SAX::Base); sub start_element { my $self = shift; my $data = shift; # do something to filter $self->SUPER::start_element($data); # GOOD (and easy) ! } This way, once you've done your job you hand the ball back to XML::SAX::Base and it takes care of all those problems for you! Note that the above example doesn't apply to filters only, drivers will benefit from the exact same feature. =head1 METHODS A number of methods are defined within this class for the purpose of inheritance. Some probably don't need to be overridden (eg parse_file) but some clearly should be (eg parse). Options for these methods are described in the PerlSAX2 specification available from http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/~checkout~/perl-xml/libxml-perl/doc/sax-2.0.html?rev=HEAD&content-type=text/html. =over 4 =item * parse The parse method is the main entry point to parsing documents. Internally the parse method will detect what type of "thing" you are parsing, and call the appropriate method in your implementation class. Here is the mapping table of what is in the Source options (see the Perl SAX 2.0 specification for the meaning of these values): Source Contains parse() calls =============== ============= CharacterStream (*) _parse_characterstream($stream, $options) ByteStream _parse_bytestream($stream, $options) String _parse_string($string, $options) SystemId _parse_systemid($string, $options) However note that these methods may not be sensible if your driver class is not for parsing XML. An example might be a DBI driver that generates XML/SAX from a database table. If that is the case, you likely want to write your own parse() method. Also note that the Source may contain both a PublicId entry, and an Encoding entry. To get at these, examine $options->{Source} as passed to your method. (*) A CharacterStream is a filehandle that does not need any encoding translation done on it. This is implemented as a regular filehandle and only works under Perl 5.7.2 or higher using PerlIO. To get a single character, or number of characters from it, use the perl core read() function. To get a single byte from it (or number of bytes), you can use sysread(). The encoding of the stream should be in the Encoding entry for the Source. =item * parse_file, parse_uri, parse_string These are all convenience variations on parse(), and in fact simply set up the options before calling it. You probably don't need to override these. =item * get_options This is a convenience method to get options in SAX2 style, or more generically either as hashes or as hashrefs (it returns a hashref). You will probably want to use this method in your own implementations of parse() and of new(). =item * get_feature, set_feature These simply get and set features, and throw the appropriate exceptions defined in the specification if need be. If your subclass defines features not defined in this one, then you should override these methods in such a way that they check for your features first, and then call the base class's methods for features not defined by your class. An example would be: sub get_feature { my $self = shift; my $feat = shift; if (exists $MY_FEATURES{$feat}) { # handle the feature in various ways } else { return $self->SUPER::get_feature($feat); } } Currently this part is unimplemented. =item * set_handler This method takes a handler type (Handler, ContentHandler, etc.) and a handler object as arguments, and changes the current handler for that handler type, while taking care of resetting the internal state that needs to be reset. This allows one to change a handler during parse without running into problems (changing it on the parser object directly will most likely cause trouble). =item * set_document_handler, set_content_handler, set_dtd_handler, set_lexical_handler, set_decl_handler, set_error_handler, set_entity_resolver These are just simple wrappers around the former method, and take a handler object as their argument. Internally they simply call set_handler with the correct arguments. =item * get_handler The inverse of set_handler, this method takes a an optional string containing a handler type (DTDHandler, ContentHandler, etc. 'Handler' is used if no type is passed). It returns a reference to the object that implements that that class, or undef if that handler type is not set for the current driver/filter. =item * get_document_handler, get_content_handler, get_dtd_handler, get_lexical_handler, get_decl_handler, get_error_handler, get_entity_resolver These are just simple wrappers around the get_handler() method, and take no arguments. Internally they simply call get_handler with the correct handler type name. =back It would be rather useless to describe all the methods that this module implements here. They are all the methods supported in SAX1 and SAX2. In case your memory is a little short, here is a list. The apparent duplicates are there so that both versions of SAX can be supported. =over 4 =item * start_document =item * end_document =item * start_element =item * start_document =item * end_document =item * start_element =item * end_element =item * characters =item * processing_instruction =item * ignorable_whitespace =item * set_document_locator =item * start_prefix_mapping =item * end_prefix_mapping =item * skipped_entity =item * start_cdata =item * end_cdata =item * comment =item * entity_reference =item * notation_decl =item * unparsed_entity_decl =item * element_decl =item * attlist_decl =item * doctype_decl =item * xml_decl =item * entity_decl =item * attribute_decl =item * internal_entity_decl =item * external_entity_decl =item * resolve_entity =item * start_dtd =item * end_dtd =item * start_entity =item * end_entity =item * warning =item * error =item * fatal_error =back =head1 TODO - more tests - conform to the "SAX Filters" and "Java and DOM compatibility" sections of the SAX2 document. =head1 AUTHOR Kip Hampton (khampton@totalcinema.com) did most of the work, after porting it from XML::Filter::Base. Robin Berjon (robin@knowscape.com) pitched in with patches to make it usable as a base for drivers as well as filters, along with other patches. Matt Sergeant (matt@sergeant.org) wrote the original XML::Filter::Base, and patched a few things here and there, and imported it into the XML::SAX distribution. =head1 SEE ALSO L =cut FOOTER open(BASE, ">" . File::Spec->catdir("lib", "XML", "SAX", "Base.pm")) || die "Cannot write Base.pm: $!"; print BASE $code; close BASE; } sub build_xml_sax_exception { my $code = <<'EOT'; package XML::SAX::Exception; use strict; use overload '""' => "stringify", 'fallback' => 1; use vars qw/$StackTrace $VERSION/; $VERSION = '1.01'; use Carp; $StackTrace = $ENV{XML_DEBUG} || 0; # Other exception classes: @XML::SAX::Exception::NotRecognized::ISA = ('XML::SAX::Exception'); @XML::SAX::Exception::NotSupported::ISA = ('XML::SAX::Exception'); @XML::SAX::Exception::Parse::ISA = ('XML::SAX::Exception'); sub throw { my $class = shift; if (ref($class)) { die $class; } die $class->new(@_); } sub new { my $class = shift; my %opts = @_; confess "Invalid options: " . join(', ', keys %opts) unless exists $opts{Message}; bless { ($StackTrace ? (StackTrace => stacktrace()) : ()), %opts }, $class; } sub stringify { my $self = shift; local $^W; my $error; if (exists $self->{LineNumber}) { $error = $self->{Message} . " [Ln: " . $self->{LineNumber} . ", Col: " . $self->{ColumnNumber} . "]"; } else { $error = $self->{Message}; } if ($StackTrace) { $error .= stackstring($self->{StackTrace}); } $error .= "\n"; return $error; } sub stacktrace { my $i = 2; my @fulltrace; while (my @trace = caller($i++)) { my %hash; @hash{qw(Package Filename Line)} = @trace[0..2]; push @fulltrace, \%hash; } return \@fulltrace; } sub stackstring { my $stacktrace = shift; my $string = "\nFrom:\n"; foreach my $current (@$stacktrace) { $string .= $current->{Filename} . " Line: " . $current->{Line} . "\n"; } return $string; } 1; __END__ =head1 NAME XML::SAX::Exception - Exception classes for XML::SAX =head1 SYNOPSIS throw XML::SAX::Exception::NotSupported( Message => "The foo feature is not supported", ); =head1 DESCRIPTION This module is the base class for all SAX Exceptions, those defined in the spec as well as those that one may create for one's own SAX errors. There are three subclasses included, corresponding to those of the SAX spec: XML::SAX::Exception::NotSupported XML::SAX::Exception::NotRecognized XML::SAX::Exception::Parse Use them wherever you want, and as much as possible when you encounter such errors. SAX is meant to use exceptions as much as possible to flag problems. =head1 CREATING NEW EXCEPTION CLASSES All you need to do to create a new exception class is: @XML::SAX::Exception::MyException::ISA = ('XML::SAX::Exception') The given package doesn't need to exist, it'll behave correctly this way. If your exception refines an existing exception class, then you may also inherit from that instead of from the base class. =head1 THROWING EXCEPTIONS This is as simple as exemplified in the SYNOPSIS. In fact, there's nothing more to know. All you have to do is: throw XML::SAX::Exception::MyException( Message => 'Something went wrong' ); and voila, you've thrown an exception which can be caught in an eval block. =cut EOT open(EXCEP, ">" . File::Spec->catdir("lib", "XML", "SAX", "Exception.pm")) || die "Cannot write Exception.pm: $!"; print EXCEP $code; close EXCEP; }