###############################################################################
#
# This file copyright (c) 2001-2011 Randy J. Ray, all rights reserved
#
# Copying and distribution are permitted under the terms of the Artistic
# License 2.0 (http://www.opensource.org/licenses/artistic-license-2.0.php) or
# the GNU LGPL (http://www.opensource.org/licenses/lgpl-2.1.php).
#
###############################################################################
#
# Description: This is the RPC::XML::Parser::XMLParser class, a container
# for the XML::Parser class.
#
# Functions: new
# parse
# message_init
# message_end
# tag_start
# error
# stack_error
# tag_end
# char_data
# extern_ent
# final
#
# Libraries: RPC::XML
# XML::Parser
#
# Global Consts: Uses $RPC::XML::ERROR
#
# Environment: None.
#
###############################################################################
package RPC::XML::Parser::XMLParser;
use 5.008008;
use strict;
use warnings;
use vars qw($VERSION);
use subs qw(error stack_error new message_init message_end tag_start tag_end
final char_data parse);
use base 'RPC::XML::Parser';
# I'm not ready to add Readonly to my list of dependencies...
## no critic (ProhibitConstantPragma)
# These constants are only used by the internal stack machine
use constant PARSE_ERROR => 0;
use constant METHOD => 1;
use constant METHODSET => 2;
use constant RESPONSE => 3;
use constant RESPONSESET => 4;
use constant STRUCT => 5;
use constant ARRAY => 6;
use constant DATATYPE => 7;
use constant ATTR_SET => 8;
use constant METHODNAME => 9;
use constant VALUEMARKER => 10;
use constant PARAMSTART => 11;
use constant PARAM => 12;
use constant PARAMENT => 13;
use constant STRUCTMEM => 14;
use constant STRUCTNAME => 15;
use constant DATAOBJECT => 16;
use constant PARAMLIST => 17;
use constant NAMEVAL => 18;
use constant MEMBERENT => 19;
use constant METHODENT => 20;
use constant RESPONSEENT => 21;
use constant FAULTENT => 22;
use constant FAULTSTART => 23;
use constant DATASTART => 24;
# This is to identify valid types
use constant VALIDTYPES => { map { ($_, 1) } qw(int i4 i8 string double
boolean dateTime.iso8601
base64 nil) };
# This maps XML tags to stack-machine tokens
use constant TAG2TOKEN => { methodCall => METHOD,
methodResponse => RESPONSE,
methodName => METHODNAME,
params => PARAMSTART,
param => PARAM,
value => VALUEMARKER,
fault => FAULTSTART,
array => ARRAY,
data => DATASTART,
struct => STRUCT,
member => STRUCTMEM,
name => STRUCTNAME };
# Members of the class
use constant M_STACK => 0;
use constant M_CDATA => 1;
use constant M_BASE64_TO_FH => 2;
use constant M_BASE64_TEMP_DIR => 3;
use constant M_SPOOLING_BASE64_DATA => 4;
use Scalar::Util 'reftype';
use XML::Parser;
require RPC::XML;
$VERSION = '1.28';
$VERSION = eval $VERSION; ## no critic (ProhibitStringyEval)
###############################################################################
#
# Sub Name: new
#
# Description: Constructor. Save any important attributes, leave the
# heavy lifting for the parse() routine and XML::Parser.
#
# Arguments: NAME IN/OUT TYPE DESCRIPTION
# $class in scalar Class we're initializing
# %attr in hash Any extras the caller wants
#
# Globals: $RPC::XML::ERROR
#
# Returns: Success: object ref
# Failure: undef
#
###############################################################################
sub new
{
my ($class, %attrs) = @_;
my $self = [];
while (my ($key, $val) = each %attrs)
{
if ($key eq 'base64_to_fh')
{
$self->[M_BASE64_TO_FH] = $val;
}
elsif ($key eq 'base64_temp_dir')
{
$self->[M_BASE64_TEMP_DIR] = $val;
}
}
return bless $self, $class;
}
###############################################################################
#
# Sub Name: parse
#
# Description: Parse the requested string or stream. This behaves mostly
# like parse() in the XML::Parser namespace, but does some
# extra, as well.
#
# Arguments: NAME IN/OUT TYPE DESCRIPTION
# $self in ref Object of this class
# $stream in scalar Either the string to parse or
# an open filehandle of sorts
#
# Returns: Success: ref to request or response object
# Failure: error string
#
###############################################################################
sub parse
{
my ($self, $stream) = @_;
my $parser = XML::Parser->new(
Namespaces => 0,
ParseParamEnt => 0,
ErrorContext => 1,
Handlers => {
Init => sub { message_init $self, @_ },
Start => sub { tag_start $self, @_ },
End => sub { tag_end $self, @_ },
Char => sub { char_data $self, @_ },
Final => sub { final $self, @_ },
ExternEnt => sub { extern_ent $self, @_ },
}
);
# If there is no stream given, then create an incremental parser handle
# and return it.
# RT58323: It's not enough to just test $stream, I have to check
# defined-ness. A 0 or null-string should yield an error, not a push-parser
# instance.
if (! defined $stream)
{
return $parser->parse_start();
}
# If the user passed a scalar ref, dereference it. This is to provide
# feature parity with the XML::LibXML-based parser.
if ((ref $stream) && (reftype($stream) eq 'SCALAR'))
{
$stream = ${$stream};
}
# If it is now any type of reference other than GLOB, we can't parse it
if ((ref $stream) && (reftype($stream) ne 'GLOB'))
{
return "Unusable reference type '$stream'";
}
my $retval;
if (! eval { $retval = $parser->parse($stream); 1; })
{
return "Parse error: $@";
}
return $retval;
}
# This is called when a new document is about to start parsing
sub message_init
{
my ($robj, $self) = @_;
$robj->[M_STACK] = [];
return $self;
}
# This is called when the parsing process is complete. There is a second arg,
# $self, that is passed but not used. So it isn't declared for now.
sub final
{
my ($robj) = @_;
# Look at the top-most marker, it'll need to be one of the end cases
my $marker = pop @{$robj->[M_STACK]};
# There should be one item on the stack after it (except in error cases)
my $retval = pop @{$robj->[M_STACK]};
# The marker has to be one of these three values, or else we didn't parse a
# valid XML-RPC document:
if (! (($marker == PARSE_ERROR) || ($marker == METHODENT) ||
($marker == RESPONSEENT)))
{
$retval = 'End-of-parse error: No error, methodCall or ' .
'methodResponse detected';
}
return $retval;
}
# This gets called each time an opening tag is parsed. In addition to the three
# args here, any attributes are passed in hash form as well. But the XML-RPC
# spec uses no attributes, so we aren't declaring them here as the list will
# (or should, at least) always be empty.
sub tag_start
{
my ($robj, $self, $elem) = @_;
$robj->[M_CDATA] = [];
if (TAG2TOKEN->{$elem})
{
push @{$robj->[M_STACK]}, TAG2TOKEN->{$elem};
}
elsif (VALIDTYPES->{$elem})
{
# All datatypes are represented on the stack by this generic token
push @{$robj->[M_STACK]}, DATATYPE;
# If the tag is <base64> and we've been told to use filehandles, set
# that up.
if (($elem eq 'base64') && $robj->[M_BASE64_TO_FH])
{
require File::Spec;
require File::Temp;
my $fh;
my $tmpdir = File::Spec->tmpdir;
if ($robj->[M_BASE64_TEMP_DIR])
{
$tmpdir = $robj->[M_BASE64_TEMP_DIR];
}
$fh = eval { File::Temp->new(UNLINK => 1, DIR => $tmpdir) };
if (! $fh)
{
push @{$robj->[M_STACK]},
"Error opening temp file for base64: $@", PARSE_ERROR;
$self->finish;
}
$robj->[M_CDATA] = $fh;
$robj->[M_SPOOLING_BASE64_DATA]= 1;
}
}
else
{
push @{$robj->[M_STACK]},
"Unknown tag encountered: $elem", PARSE_ERROR;
$self->finish;
}
return;
}
# Very simple error-text generator, just to eliminate heavy reduncancy in the
# next sub:
sub error
{
my ($robj, $self, $mesg, $elem) = @_;
$elem ||= q{};
my $fmt = $elem ?
'%s at document line %d, column %d (byte %d, closing tag %s)' :
'%s at document line %d, column %d (byte %d)';
push @{$robj->[M_STACK]},
sprintf($fmt, $mesg, $self->current_line, $self->current_column,
$self->current_byte, $elem),
PARSE_ERROR;
$self->finish;
return;
}
# A shorter-cut for stack integrity errors
sub stack_error
{
my ($robj, $self, $elem) = @_;
return error($robj, $self, 'Stack corruption detected', $elem);
}
# This is a hairy subroutine-- what to do at the end-tag. The actions range
# from simply new-ing a datatype all the way to building the final object.
sub tag_end ## no critic (ProhibitExcessComplexity)
{
my ($robj, $self, $elem) = @_;
my ($op, $newobj, $class, $list, $name);
# This should always be one of the stack machine ops defined above
$op = pop @{$robj->[M_STACK]};
my $cdata = q{};
if ($robj->[M_SPOOLING_BASE64_DATA])
{
$cdata = $robj->[M_CDATA];
seek $cdata, 0, 0;
}
elsif ($robj->[M_CDATA])
{
$cdata = join q{} => @{$robj->[M_CDATA]};
}
# Decide what to do from here
if (VALIDTYPES->{$elem}) ## no critic (ProhibitCascadingIfElse)
{
# This is the closing tag of one of the data-types.
$class = $elem;
# Cheaper than the regex that was here, and more locale-portable
if ($class eq 'dateTime.iso8601')
{
$class = 'datetime_iso8601';
}
# Some minimal data-integrity checking
if ($class eq 'int' or $class eq 'i4' or $class eq 'i8')
{
if ($cdata !~ /^[-+]?\d+$/)
{
return error($robj, $self, 'Bad integer data read');
}
}
elsif ($class eq 'double')
{
if ($cdata !~
# Taken from perldata(1)
/^[+-]?(?=\d|[.]\d)\d*(?:[.]\d*)?(?:[Ee](?:[+-]?\d+))?$/x)
{
return error($robj, $self, 'Bad floating-point data read');
}
}
elsif ($class eq 'nil')
{
# We now allow parsing of <nil/> at all times.
# By definition though, it must be, well... nil.
if ($cdata !~ /^\s*$/)
{
return error($robj, $self, '<nil /> element must be empty');
}
}
$class = "RPC::XML::$class";
# The string at the end is only seen by the RPC::XML::base64 class
$newobj = $class->new($cdata, 'base64 is encoded, nil is allowed');
push @{$robj->[M_STACK]}, $newobj, DATAOBJECT;
if ($robj->[M_SPOOLING_BASE64_DATA])
{
$robj->[M_SPOOLING_BASE64_DATA] = 0;
$robj->[M_CDATA] = undef; # Won't close FH, $newobj still holds it
}
}
elsif ($elem eq 'value')
{
# For <value></value>, there should already be a dataobject, or else
# the marker token in which case the CDATA is used as a string value.
if ($op == DATAOBJECT)
{
($op, $newobj) = splice @{$robj->[M_STACK]}, -2;
if ($op != VALUEMARKER)
{
return stack_error($robj, $self, $elem);
}
}
else
{
$newobj = RPC::XML::string->new($cdata);
}
push @{$robj->[M_STACK]}, $newobj, DATAOBJECT;
}
elsif ($elem eq 'param')
{
# Almost like above, since this is really a NOP anyway. But it also
# puts PARAMENT on the stack, so that the closing tag of <params />
# can check for bad content.
if ($op != DATAOBJECT)
{
return error($robj, $self,
'No <value> found within <param> container');
}
($op, $newobj) = splice @{$robj->[M_STACK]}, -2;
if ($op != PARAM)
{
return error($robj, $self, "Illegal content in $elem tag");
}
push @{$robj->[M_STACK]}, $newobj, PARAMENT;
}
elsif ($elem eq 'params')
{
# At this point, there should be zero or more PARAMENT tokens on the
# stack, each with an object right below it.
$list = [];
if ($op != PARAMENT && $op != PARAMSTART)
{
return error($robj, $self, "Illegal content in $elem tag");
}
while ($op == PARAMENT)
{
unshift @{$list}, pop @{$robj->[M_STACK]};
$op = pop @{$robj->[M_STACK]};
}
# Now that we see something ! PARAMENT, it needs to be PARAMSTART
if ($op != PARAMSTART)
{
return error($robj, $self, "Illegal content in $elem tag");
}
push @{$robj->[M_STACK]}, $list, PARAMLIST;
}
elsif ($elem eq 'fault')
{
# If we're finishing up a fault definition, there needs to be a struct
# on the stack.
if ($op != DATAOBJECT)
{
return stack_error($robj, $self, $elem);
}
($op, $newobj) = splice @{$robj->[M_STACK]}, -2;
if (! $newobj->isa('RPC::XML::struct'))
{
return error($robj, $self,
'Only a <struct> value may be within a <fault>');
}
$newobj = RPC::XML::fault->new($newobj);
if (! $newobj)
{
return error($robj, $self, 'Unable to instantiate fault object: ' .
$RPC::XML::ERROR);
}
push @{$robj->[M_STACK]}, $newobj, FAULTENT;
}
elsif ($elem eq 'member')
{
# We need to see a DATAOBJECT followed by a STRUCTNAME
if ($op != DATAOBJECT)
{
return error(
$robj, $self, 'Element mismatch, expected to see value'
);
}
($op, $newobj) = splice @{$robj->[M_STACK]}, -2;
if ($op != STRUCTNAME)
{
return error(
$robj, $self, 'Element mismatch, expected to see name'
);
}
# Get the name off the stack to clear the way for the STRUCTMEM marker
# under it
($op, $name) = splice @{$robj->[M_STACK]}, -2;
# Push the name back on, with the value and the new marker (STRUCTMEM)
push @{$robj->[M_STACK]}, $name, $newobj, STRUCTMEM;
}
elsif ($elem eq 'name')
{
# Fairly simple: just push the current content of CDATA on w/ a marker
push @{$robj->[M_STACK]}, $cdata, STRUCTNAME;
}
elsif ($elem eq 'struct')
{
# Create the hash table in-place, then pass the ref to the constructor
$list = {};
# First off the stack needs to be STRUCTMEM or STRUCT
if (! ($op == STRUCTMEM or $op == STRUCT))
{
return error(
$robj, $self, 'Element mismatch, expected to see member'
);
}
while ($op == STRUCTMEM)
{
# Next on stack (in list-order): name, value
($name, $newobj) = splice @{$robj->[M_STACK]}, -2;
$list->{$name} = $newobj;
$op = pop @{$robj->[M_STACK]};
}
# Now that we see something ! STRUCTMEM, it needs to be STRUCT
if ($op != STRUCT)
{
return error($robj, $self, 'Bad content inside struct block');
}
$newobj = RPC::XML::struct->new($list);
push @{$robj->[M_STACK]}, $newobj, DATAOBJECT;
}
elsif ($elem eq 'data')
{
# The <data></data> block within an <array></array> declaration serves
# to gather together all the <value /> elements that will make up the
# resulting list.
#
# Go down the stack, gathering DATAOBJECT markers until we see the
# DATASTART marker.
$list = [];
# Only DATAOBJECT and DATASTART should be visible
if ($op != DATASTART && $op != DATAOBJECT)
{
return error($robj, $self, 'Bad content inside data block');
}
while ($op == DATAOBJECT)
{
unshift @{$list}, pop @{$robj->[M_STACK]};
$op = pop @{$robj->[M_STACK]};
}
# Now that we see something ! DATAOBJECT, it needs to be DATASTART
if ($op != DATASTART)
{
return error($robj, $self, "Illegal content in $elem tag");
}
# We might as well instantiate the RPC::XML::array object here, and
# put it on the stack with a DATAOBJECT marker. Then the end-tag of
# the <array /> can just look to make sure there is exactly one
# DATAOBJECT/value pair between it and the start of the array.
$newobj = RPC::XML::array->new(from => $list);
push @{$robj->[M_STACK]}, $newobj, DATAOBJECT;
}
elsif ($elem eq 'array')
{
# Now that we process the <data /> block directly (I used to just
# ignore it), handling the closing tag of <array /> is just a matter
# of making sure $op is DATAOBJECT and that we have an array object
# on the stack with an ARRAY marker just below it.
# Only DATAOBJECT or ARRAY should be visible
if ($op == DATAOBJECT)
{
($op, $newobj) = splice @{$robj->[M_STACK]}, -2;
}
# Now only ARRAY should be
if ($op != ARRAY)
{
return error($robj, $self, "Illegal content in $elem tag");
}
# Technically, this is a little redundant, since we had these two right
# here on the stack when we started. But at this point we've validated
# the form of the <array /> block and removed the ARRAY marker from the
# stack.
push @{$robj->[M_STACK]}, $newobj, DATAOBJECT;
}
elsif ($elem eq 'methodName')
{
if ($robj->[M_STACK]->[$#{$robj->[M_STACK]}] != METHOD)
{
return error(
$robj, $self,
"$elem tag must immediately follow a methodCall tag"
);
}
push @{$robj->[M_STACK]}, $cdata, NAMEVAL;
}
elsif ($elem eq 'methodCall')
{
# A methodCall closing should have on the stack an optional PARAMLIST
# marker, a NAMEVAL marker, then the METHOD token from the
# opening tag.
if ($op == PARAMLIST)
{
($op, $list) = splice @{$robj->[M_STACK]}, -2;
}
else
{
$list = [];
}
if ($op == NAMEVAL)
{
($op, $name) = splice @{$robj->[M_STACK]}, -2;
}
elsif ($op != METHOD)
{
return error(
$robj, $self,
'Extra content in "methodCall" block detected'
);
}
if (! $name)
{
return error(
$robj, $self,
'No methodName tag detected during methodCall parsing'
);
}
# Create the request object and push it on the stack
$newobj = RPC::XML::request->new($name, @{$list});
if (! $newobj)
{
return error($robj, $self,
"Error creating request object: $RPC::XML::ERROR");
}
push @{$robj->[M_STACK]}, $newobj, METHODENT;
}
elsif ($elem eq 'methodResponse')
{
# A methodResponse closing should have on the stack only the
# DATAOBJECT marker, then the RESPONSE token from the opening tag.
if ($op == PARAMLIST)
{
# To my knowledge, the XML-RPC spec limits the params list for
# a response to exactly one object. Extract it from the listref
# and put it back.
$list = pop @{$robj->[M_STACK]};
if (@{$list} > 1)
{
return error(
$robj, $self,
"Params list for $elem tag invalid: too many params"
);
}
elsif (@{$list} == 0)
{
return error(
$robj, $self,
"Params list for $elem tag invalid: no params"
);
}
push @{$robj->[M_STACK]}, $list->[0];
}
elsif ($op != DATAOBJECT && $op != FAULTENT)
{
return error($robj, $self,
"No parameter was declared for the $elem tag");
}
($op, $list) = splice @{$robj->[M_STACK]}, -2;
if ($op != RESPONSE)
{
return stack_error($robj, $self, $elem);
}
# Create the response object and push it on the stack
$newobj = RPC::XML::response->new($list);
push @{$robj->[M_STACK]}, $newobj, RESPONSEENT;
}
return;
}
# This just spools the character data until a closing tag makes use of it
sub char_data
{
my ($robj, undef, $characters) = @_;
if ($robj->[M_SPOOLING_BASE64_DATA])
{
print {$robj->[M_CDATA]} $characters;
}
else
{
push @{$robj->[M_CDATA]}, $characters;
}
return;
}
# At some future point, this may be expanded to provide more entities than
# just the basic XML ones.
sub extern_ent
{
return q{};
}
# Exception-throwing stub in case this is called without first getting the
# XML::Parser::ExpatNB instance:
sub parse_more
{
die __PACKAGE__ . '::parse_more: Must be called on a push-parser ' .
"instance obtained from parse()\n";
}
# Exception-throwing stub in case this is called without first getting the
# XML::Parser::ExpatNB instance:
sub parse_done
{
die __PACKAGE__ . '::parse_done: Must be called on a push-parser ' .
"instance obtained from parse()\n";
}
1;
__END__
=head1 NAME
RPC::XML::Parser::XMLParser - A container class for XML::Parser
=head1 SYNOPSIS
# This class should rarely (if ever) be used directly:
use RPC::XML::ParserFactory 'XML::Parser';
...
$P = RPC::XML::ParserFactory->new();
$P->parse($message);
=head1 DESCRIPTION
This class implements the interface defined in the B<RPC::XML::Parser>
factory-class (see L<RPC::XML::Parser|RPC::XML::Parser>) using the
B<XML::Parser> module to handle the actual manipulation of XML.
=head1 SUBROUTINES/METHODS
This module implements the public-facing methods as described in
L<RPC::XML::Parser|RPC::XML::Parser>:
=over 4
=item new [ ARGS ]
The constructor only recognizes the two parameters specified in the base
class (for the B<RPC::XML::base64> file-spooling operations).
=item parse [ STRING | STREAM ]
The parse() method accepts either a string of XML, a filehandle of some sort,
or no argument at all. In the latter case, the return value is a parser
instance that acts as a push-parser (a non-blocking parser). For the first
two types of input, the return value is either a message object (one of
B<RPC::XML::request> or B<RPC::XML::response>) or an error.
=item parse_more STRING
(Only callable on a push-parser instance) Parses the chunk of XML, which does
not have to describe a complete document, and adds it to the current running
document. If this method is called on a parser instance that is not a
push-parser, an exception is thrown.
=item parse_done
(Only callable on a push-parser instance) Finishes the parsing process and
returns either a message object (one of B<RPC::XML::request> or
B<RPC::XML::response>) or an error (if the document was incomplete, not
well-formed, or not valid). If this method is called on a parser instance that
is not a push-parser, an exception is thrown.
=back
=head1 DIAGNOSTICS
All methods return some type of reference on success. The B<new> and B<parse>
methods return message strings on errors. The B<parse_more> and B<parse_done>
methods may throw exceptions on errors, if the error occurs at the
B<XML::Parser> level.
=head1 EXTERNAL ENTITIES
As of version 1.24 of this module (version 0.75 of the B<RPC::XML> suite),
external entities whose URI is a C<file:/> scheme (local file) are explicitly
ignored. This is for security purposes.
=head1 BUGS
Please report any bugs or feature requests to
C<bug-rpc-xml at rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=RPC-XML>. I will be
notified, and then you'll automatically be notified of progress on
your bug as I make changes.
=head1 SUPPORT
=over 4
=item * RT: CPAN's request tracker
L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=RPC-XML>
=item * AnnoCPAN: Annotated CPAN documentation
L<http://annocpan.org/dist/RPC-XML>
=item * CPAN Ratings
L<http://cpanratings.perl.org/d/RPC-XML>
=item * Search CPAN
L<http://search.cpan.org/dist/RPC-XML>
=item * MetaCPAN
L<https://metacpan.org/release/RPC-XML>
=item * Source code on GitHub
L<http://github.com/rjray/rpc-xml>
=back
=head1 LICENSE AND COPYRIGHT
This file and the code within are copyright (c) 2011 by Randy J. Ray.
Copying and distribution are permitted under the terms of the Artistic
License 2.0 (L<http://www.opensource.org/licenses/artistic-license-2.0.php>) or
the GNU LGPL 2.1 (L<http://www.opensource.org/licenses/lgpl-2.1.php>).
=head1 CREDITS
The B<XML-RPC> standard is Copyright (c) 1998-2001, UserLand Software, Inc.
See <http://www.xmlrpc.com> for more information about the B<XML-RPC>
specification.
=head1 SEE ALSO
L<RPC::XML|RPC::XML>, L<RPC::XML::Parser|RPC::XML::Parser>,
L<XML::Parser|XML::Parser>
=head1 AUTHOR
Randy J. Ray <rjray@blackperl.com>
=cut