name : NamespaceSupport.pm package XML::NamespaceSupport; use strict; our $VERSION = '1.12'; # VERSION # ABSTRACT: A simple generic namespace processor use constant FATALS => 0; # root object use constant NSMAP => 1; use constant UNKNOWN_PREF => 2; use constant AUTO_PREFIX => 3; use constant XMLNS_11 => 4; use constant DEFAULT => 0; # maps use constant PREFIX_MAP => 1; use constant DECLARATIONS => 2; use vars qw($NS_XMLNS $NS_XML); $NS_XMLNS = 'http://www.w3.org/2000/xmlns/'; $NS_XML = 'http://www.w3.org/XML/1998/namespace'; # add the ns stuff that baud wants based on Java's xml-writer #-------------------------------------------------------------------# # constructor #-------------------------------------------------------------------# sub new { my $class = ref($_[0]) ? ref(shift) : shift; my $options = shift; my $self = [ 1, # FATALS [[ # NSMAP undef, # DEFAULT { xml => $NS_XML }, # PREFIX_MAP undef, # DECLARATIONS ]], 'aaa', # UNKNOWN_PREF 0, # AUTO_PREFIX 1, # XML_11 ]; $self->[NSMAP]->[0]->[PREFIX_MAP]->{xmlns} = $NS_XMLNS if $options->{xmlns}; $self->[FATALS] = $options->{fatal_errors} if defined $options->{fatal_errors}; $self->[AUTO_PREFIX] = $options->{auto_prefix} if defined $options->{auto_prefix}; $self->[XMLNS_11] = $options->{xmlns_11} if defined $options->{xmlns_11}; return bless $self, $class; } #-------------------------------------------------------------------# # reset() - return to the original state (for reuse) #-------------------------------------------------------------------# sub reset { my $self = shift; $#{$self->[NSMAP]} = 0; } #-------------------------------------------------------------------# # push_context() - add a new empty context to the stack #-------------------------------------------------------------------# sub push_context { my $self = shift; push @{$self->[NSMAP]}, [ $self->[NSMAP]->[-1]->[DEFAULT], { %{$self->[NSMAP]->[-1]->[PREFIX_MAP]} }, [], ]; } #-------------------------------------------------------------------# # pop_context() - remove the topmost context from the stack #-------------------------------------------------------------------# sub pop_context { my $self = shift; die 'Trying to pop context without push context' unless @{$self->[NSMAP]} > 1; pop @{$self->[NSMAP]}; } #-------------------------------------------------------------------# # declare_prefix() - declare a prefix in the current scope #-------------------------------------------------------------------# sub declare_prefix { my $self = shift; my $prefix = shift; my $value = shift; warn <<' EOWARN' unless defined $prefix or $self->[AUTO_PREFIX]; Prefix was undefined. If you wish to set the default namespace, use the empty string ''. If you wish to autogenerate prefixes, set the auto_prefix option to a true value. EOWARN no warnings 'uninitialized'; if ($prefix eq 'xml' and $value ne $NS_XML) { die "The xml prefix can only be bound to the $NS_XML namespace." } elsif ($value eq $NS_XML and $prefix ne 'xml') { die "the $NS_XML namespace can only be bound to the xml prefix."; } elsif ($value eq $NS_XML and $prefix eq 'xml') { return 1; } return 0 if index(lc($prefix), 'xml') == 0; use warnings 'uninitialized'; if (defined $prefix and $prefix eq '') { $self->[NSMAP]->[-1]->[DEFAULT] = $value; } else { die "Cannot declare prefix $prefix" if $value eq '' and not $self->[XMLNS_11]; if (not defined $prefix and $self->[AUTO_PREFIX]) { while (1) { $prefix = $self->[UNKNOWN_PREF]++; last if not exists $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix}; } } elsif (not defined $prefix and not $self->[AUTO_PREFIX]) { return 0; } $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix} = $value; } push @{$self->[NSMAP]->[-1]->[DECLARATIONS]}, $prefix; return 1; } #-------------------------------------------------------------------# # declare_prefixes() - declare several prefixes in the current scope #-------------------------------------------------------------------# sub declare_prefixes { my $self = shift; my %prefixes = @_; while (my ($k,$v) = each %prefixes) { $self->declare_prefix($k,$v); } } #-------------------------------------------------------------------# # undeclare_prefix #-------------------------------------------------------------------# sub undeclare_prefix { my $self = shift; my $prefix = shift; return if not defined($prefix); return unless exists $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix}; my ( $tfix ) = grep { $_ eq $prefix } @{$self->[NSMAP]->[-1]->[DECLARATIONS]}; if ( not defined $tfix ) { die "prefix $prefix not declared in this context\n"; } @{$self->[NSMAP]->[-1]->[DECLARATIONS]} = grep { $_ ne $prefix } @{$self->[NSMAP]->[-1]->[DECLARATIONS]}; delete $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix}; } #-------------------------------------------------------------------# # get_prefix() - get a (random) prefix for a given URI #-------------------------------------------------------------------# sub get_prefix { my $self = shift; my $uri = shift; # we have to iterate over the whole hash here because if we don't # the iterator isn't reset and the next pass will fail my $pref; while (my ($k, $v) = each %{$self->[NSMAP]->[-1]->[PREFIX_MAP]}) { $pref = $k if $v eq $uri; } return $pref; } #-------------------------------------------------------------------# # get_prefixes() - get all the prefixes for a given URI #-------------------------------------------------------------------# sub get_prefixes { my $self = shift; my $uri = shift; return keys %{$self->[NSMAP]->[-1]->[PREFIX_MAP]} unless defined $uri; return grep { $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$_} eq $uri } keys %{$self->[NSMAP]->[-1]->[PREFIX_MAP]}; } #-------------------------------------------------------------------# # get_declared_prefixes() - get all prefixes declared in the last context #-------------------------------------------------------------------# sub get_declared_prefixes { my $declarations = $_[0]->[NSMAP]->[-1]->[DECLARATIONS]; die "At least one context must be pushed onto stack with push_context()\n", "before calling get_declared_prefixes()" if not defined $declarations; return @{$_[0]->[NSMAP]->[-1]->[DECLARATIONS]}; } #-------------------------------------------------------------------# # get_uri() - get a URI given a prefix #-------------------------------------------------------------------# sub get_uri { my $self = shift; my $prefix = shift; warn "Prefix must not be undef in get_uri(). The emtpy prefix must be ''" unless defined $prefix; return $self->[NSMAP]->[-1]->[DEFAULT] if $prefix eq ''; return $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix} if exists $self->[NSMAP]->[-1]->[PREFIX_MAP]->{$prefix}; return undef; } #-------------------------------------------------------------------# # process_name() - provide details on a name #-------------------------------------------------------------------# sub process_name { my $self = shift; my $qname = shift; my $aflag = shift; if ($self->[FATALS]) { return( ($self->_get_ns_details($qname, $aflag))[0,2], $qname ); } else { eval { return( ($self->_get_ns_details($qname, $aflag))[0,2], $qname ); } } } #-------------------------------------------------------------------# # process_element_name() - provide details on a element's name #-------------------------------------------------------------------# sub process_element_name { my $self = shift; my $qname = shift; if ($self->[FATALS]) { return $self->_get_ns_details($qname, 0); } else { eval { return $self->_get_ns_details($qname, 0); } } } #-------------------------------------------------------------------# # process_attribute_name() - provide details on a attribute's name #-------------------------------------------------------------------# sub process_attribute_name { my $self = shift; my $qname = shift; if ($self->[FATALS]) { return $self->_get_ns_details($qname, 1); } else { eval { return $self->_get_ns_details($qname, 1); } } } #-------------------------------------------------------------------# # ($ns, $prefix, $lname) = $self->_get_ns_details($qname, $f_attr) # returns ns, prefix, and lname for a given attribute name # >> the $f_attr flag, if set to one, will work for an attribute #-------------------------------------------------------------------# sub _get_ns_details { my $self = shift; my $qname = shift; my $aflag = shift; my ($ns, $prefix, $lname); (my ($tmp_prefix, $tmp_lname) = split /:/, $qname, 3) < 3 or die "Invalid QName: $qname"; # no prefix my $cur_map = $self->[NSMAP]->[-1]; if (not defined($tmp_lname)) { $prefix = undef; $lname = $qname; # attr don't have a default namespace $ns = ($aflag) ? undef : $cur_map->[DEFAULT]; } # prefix else { if (exists $cur_map->[PREFIX_MAP]->{$tmp_prefix}) { $prefix = $tmp_prefix; $lname = $tmp_lname; $ns = $cur_map->[PREFIX_MAP]->{$prefix} } else { # no ns -> lname == name, all rest undef die "Undeclared prefix: $tmp_prefix"; } } return ($ns, $prefix, $lname); } #-------------------------------------------------------------------# # parse_jclark_notation() - parse the Clarkian notation #-------------------------------------------------------------------# sub parse_jclark_notation { shift; my $jc = shift; $jc =~ m/^\{(.*)\}([^}]+)$/; return $1, $2; } #-------------------------------------------------------------------# # Java names mapping #-------------------------------------------------------------------# *XML::NamespaceSupport::pushContext = \&push_context; *XML::NamespaceSupport::popContext = \&pop_context; *XML::NamespaceSupport::declarePrefix = \&declare_prefix; *XML::NamespaceSupport::declarePrefixes = \&declare_prefixes; *XML::NamespaceSupport::getPrefix = \&get_prefix; *XML::NamespaceSupport::getPrefixes = \&get_prefixes; *XML::NamespaceSupport::getDeclaredPrefixes = \&get_declared_prefixes; *XML::NamespaceSupport::getURI = \&get_uri; *XML::NamespaceSupport::processName = \&process_name; *XML::NamespaceSupport::processElementName = \&process_element_name; *XML::NamespaceSupport::processAttributeName = \&process_attribute_name; *XML::NamespaceSupport::parseJClarkNotation = \&parse_jclark_notation; *XML::NamespaceSupport::undeclarePrefix = \&undeclare_prefix; 1; __END__ =pod =encoding UTF-8 =head1 NAME XML::NamespaceSupport - A simple generic namespace processor =head1 VERSION version 1.12 =head1 SYNOPSIS use XML::NamespaceSupport; my $nsup = XML::NamespaceSupport->new; # add a new empty context $nsup->push_context; # declare a few prefixes $nsup->declare_prefix($prefix1, $uri1); $nsup->declare_prefix($prefix2, $uri2); # the same shorter $nsup->declare_prefixes($prefix1 => $uri1, $prefix2 => $uri2); # get a single prefix for a URI (randomly) $prefix = $nsup->get_prefix($uri); # get all prefixes for a URI (probably better) @prefixes = $nsup->get_prefixes($uri); # get all prefixes in scope @prefixes = $nsup->get_prefixes(); # get all prefixes that were declared for the current scope @prefixes = $nsup->get_declared_prefixes; # get a URI for a given prefix $uri = $nsup->get_uri($prefix); # get info on a qname (java-ish way, it's a bit weird) ($ns_uri, $local_name, $qname) = $nsup->process_name($qname, $is_attr); # the same, more perlish ($ns_uri, $prefix, $local_name) = $nsup->process_element_name($qname); ($ns_uri, $prefix, $local_name) = $nsup->process_attribute_name($qname); # remove the current context $nsup->pop_context; # reset the object for reuse in another document $nsup->reset; # a simple helper to process Clarkian Notation my ($ns, $lname) = $nsup->parse_jclark_notation('{http://foo}bar'); # or (given that it doesn't care about the object my ($ns, $lname) = XML::NamespaceSupport->parse_jclark_notation('{http://foo}bar'); =head1 DESCRIPTION This module offers a simple to process namespaced XML names (unames) from within any application that may need them. It also helps maintain a prefix to namespace URI map, and provides a number of basic checks. The model for this module is SAX2's NamespaceSupport class, readable at http://www.saxproject.org/namespaces.html It adds a few perlisations where we thought it appropriate. =head1 NAME XML::NamespaceSupport - a simple generic namespace support class =head1 METHODS =over 4 =item * XML::NamespaceSupport->new(\%options) A simple constructor. The options are C<xmlns>, C<fatal_errors>, and C<auto_prefix> If C<xmlns> is turned on (it is off by default) the mapping from the xmlns prefix to the URI defined for it in DOM level 2 is added to the list of predefined mappings (which normally only contains the xml prefix mapping). If C<fatal_errors> is turned off (it is on by default) a number of validity errors will simply be flagged as failures, instead of die()ing. If C<auto_prefix> is turned on (it is off by default) when one provides a prefix of C<undef> to C<declare_prefix> it will generate a random prefix mapped to that namespace. Otherwise an undef prefix will trigger a warning (you should probably know what you're doing if you turn this option on). If C<xmlns_11> us turned off, it becomes illegal to undeclare namespace prefixes. It is on by default. This behaviour is compliant with Namespaces in XML 1.1, turning it off reverts you to version 1.0. =item * $nsup->push_context Adds a new empty context to the stack. You can then populate it with new prefixes defined at this level. =item * $nsup->pop_context Removes the topmost context in the stack and reverts to the previous one. It will die() if you try to pop more than you have pushed. =item * $nsup->declare_prefix($prefix, $uri) Declares a mapping of $prefix to $uri, at the current level. Note that with C<auto_prefix> turned on, if you declare a prefix mapping in which $prefix is undef(), you will get an automatic prefix selected for you. If it is off you will get a warning. This is useful when you deal with code that hasn't kept prefixes around and need to reserialize the nodes. It also means that if you want to set the default namespace (i.e. with an empty prefix) you must use the empty string instead of undef. This behaviour is consistent with the SAX 2.0 specification. =item * $nsup->declare_prefixes(%prefixes2uris) Declares a mapping of several prefixes to URIs, at the current level. =item * $nsup->get_prefix($uri) Returns a prefix given a URI. Note that as several prefixes may be mapped to the same URI, it returns an arbitrary one. It'll return undef on failure. =item * $nsup->get_prefixes($uri) Returns an array of prefixes given a URI. It'll return all the prefixes if the uri is undef. =item * $nsup->get_declared_prefixes Returns an array of all the prefixes that have been declared within this context, ie those that were declared on the last element, not those that were declared above and are simply in scope. Note that at least one context must be added to the stack via C<push_context> before this method can be called. =item * $nsup->get_uri($prefix) Returns a URI for a given prefix. Returns undef on failure. =item * $nsup->process_name($qname, $is_attr) Given a qualified name and a boolean indicating whether this is an attribute or another type of name (those are differently affected by default namespaces), it returns a namespace URI, local name, qualified name tuple. I know that that is a rather abnormal list to return, but it is so for compatibility with the Java spec. See below for more Perlish alternatives. If the prefix is not declared, or if the name is not valid, it'll either die or return undef depending on the current setting of C<fatal_errors>. =item * $nsup->undeclare_prefix($prefix); Removes a namespace prefix from the current context. This function may be used in SAX's end_prefix_mapping when there is fear that a namespace declaration might be available outside their scope (which shouldn't normally happen, but you never know ;) ). This may be needed in order to properly support Namespace 1.1. =item * $nsup->process_element_name($qname) Given a qualified name, it returns a namespace URI, prefix, and local name tuple. This method applies to element names. If the prefix is not declared, or if the name is not valid, it'll either die or return undef depending on the current setting of C<fatal_errors>. =item * $nsup->process_attribute_name($qname) Given a qualified name, it returns a namespace URI, prefix, and local name tuple. This method applies to attribute names. If the prefix is not declared, or if the name is not valid, it'll either die or return undef depending on the current setting of C<fatal_errors>. =item * $nsup->reset Resets the object so that it can be reused on another document. =back All methods of the interface have an alias that is the name used in the original Java specification. You can use either name interchangeably. Here is the mapping: Java name Perl name --------------------------------------------------- pushContext push_context popContext pop_context declarePrefix declare_prefix declarePrefixes declare_prefixes getPrefix get_prefix getPrefixes get_prefixes getDeclaredPrefixes get_declared_prefixes getURI get_uri processName process_name processElementName process_element_name processAttributeName process_attribute_name parseJClarkNotation parse_jclark_notation undeclarePrefix undeclare_prefix =head1 VARIABLES Two global variables are made available to you. They used to be constants but simple scalars are easier to use in a number of contexts. They are not exported but can easily be accessed from any package, or copied into it. =over 4 =item * C<$NS_XMLNS> The namespace for xmlns prefixes, http://www.w3.org/2000/xmlns/. =item * C<$NS_XML> The namespace for xml prefixes, http://www.w3.org/XML/1998/namespace. =back =head1 TODO - add more tests - optimise here and there =head1 SEE ALSO XML::Parser::PerlSAX =head1 AUTHORS =over 4 =item * Robin Berjon <robin@knowscape.com> =item * Chris Prather <chris@prather.org> =back =head1 COPYRIGHT AND LICENSE This software is copyright (c) 2015 by Robin Berjon. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. =head1 CONTRIBUTORS =for stopwords Chris Prather David Steinbrunner Paul Cochrane Paulo Custodio =over 4 =item * Chris Prather <cprather@hdpublishing.com> =item * David Steinbrunner <dsteinbrunner@pobox.com> =item * Paul Cochrane <paul@liekut.de> =item * Paulo Custodio <pauloscustodio@gmail.com> =back =cut