Provided by: librpc-xml-perl_0.80-2_all 
NAME
make_method - Turn Perl code into an XML description for RPC::XML::Server
SYNOPSIS
make_method --name=system.identification --helptext='System ID string'
--signature=string --code=ident.pl --output=ident.xpl
make_method --base=methods/identification
DESCRIPTION
This is a simple tool to create the XML descriptive files for specifying methods to be published by an
RPC::XML::Server-based server.
If a server is written such that the methods it exports (or publishes) are a part of the running code,
then there is no need for this tool. However, in cases where the server may be separate and distinct from
the code (such as an Apache-based RPC server), specifying the routines and filling in the supporting
information can be cumbersome.
One solution that the RPC::XML::Server package offers is the means to load publishable code from an
external file. The file is in a simple XML dialect that clearly delinates the externally-visible name,
the method signatures, the help text and the code itself. These files may be created manually, or this
tool may be used as an aide.
REQUIRED ARGUMENTS
There are no required arguments, but if there are not sufficient options passed you will be told by an
error message.
OPTIONS
The tool recognizes the following options:
--help
Prints a short summary of the options.
--name=STRING
Specifies the published name of the method being encoded. This is the name by which it will be
visible to clients of the server.
--namespace=STRING
Specifies a namespace that the code of the method will be evaluated in, when the XPL file is loaded
by a server instance.
--type=STRING
Specify the type for the resulting file. "Type" here refers to whether the container tag used in the
resulting XML will specify a procedure or a method. The default is method. The string is treated
case-independant, and only the first character ("m" or "p") is actually regarded.
--version=STRING
Specify a version stamp for the code routine.
--hidden
If this is passe, the resulting file will include a tag that tells the server daemon to not make the
routine visible through any introspection interfaces.
--signature=STRING [ --signature=STRING ... ]
Specify one or more signatures for the method. Signatures should be the type names as laid out in the
documentation in RPC::XML, with the elements separated by a colon. You may also separate them with
spaces, if you quote the argument. This option may be specified more than once, as some methods may
have several signatures.
--helptext=STRING
Specify the help text for the method as a simple string on the command line. Not suited for terribly
long help strings.
--helpfile=FILE
Read the help text for the method from the file specified.
--code=FILE
Read the actual code for the routine from the file specified. If this option is not given, the code
is read from the standard input file descriptor.
--output=FILE
Write the resulting XML representation to the specified file. If this option is not given, then the
output goes to the standard output file descriptor.
--base=NAME
This is a special, "all-in-one" option. If passed, all other options are ignored.
The value is used as the base element for reading information from a file named BASE.base. This file
will contain specification of the name, version, hidden status, signatures and other method
information. Each line of the file should look like one of the following:
Name: STRING
Specify the name of the routine being published. If this line does not appear, then the value of
the --base argument with all directory elements removed will be used.
Version: STRING
Provide a version stamp for the function. If no line matching this pattern is present, no version
tag will be written.
Hidden: STRING
If present, STRING should be either "yes" or "no" (case not important). If it is "yes", then the
method is marked to be hidden from any introspection API.
Signature: STRING
This line may appear more than once, and is treated cumulatively. Other options override previous
values if they appear more than once. The portion following the "Signature:" part is taken to be
a published signature for the method, with elements separated by whitespace. Each method must
have at least one signature, so a lack of any will cause an error.
Helpfile: STRING
Specifies the file from which to read the help text. It is not an error if no help text is
specified.
Codefile: STRING
Specifies the file from which to read the code. Code is assumed to be Perl, and will be tagged as
such in the resulting file.
Codefile[lang]: string
Specifies the file from which to read code, while also identifying the language that the code is
in. This allows for the creation of a XPL file that includes multiple language implementations of
the given method or procedure.
Any other lines than the above patterns are ignored.
If no code has been read, then the tool will exit with an error message.
The output is written to BASE.xpl, preserving the path information so that the resulting file is
right alongside the source files. This allows constructs such as:
make_method --base=methods/introspection
FILE FORMAT AND DTD
The file format for these published routines is a very simple XML dialect. This is less due to XML being
an ideal format than it is the availability of the parser, given that the RPC::XML::Server class will
already have the parser code in core. Writing a completely new format would not have gained anything.
The Document Type Declaration for the format can be summarized by:
<!ELEMENT proceduredef (name, namespace?, version?, hidden?,
signature+, help?, code)>
<!ELEMENT methoddef (name, namespace?, version?, hidden?,
signature+, help?, code)>
<!ELEMENT functiondef (name, namespace?, version?, hidden?,
signature+, help?, code)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT namespace (#PCDATA)>
<!ELEMENT version (#PCDATA)>
<!ELEMENT hidden EMPTY>
<!ELEMENT signature (#PCDATA)>
<!ELEMENT help (#PCDATA)>
<!ELEMENT code (#PCDATA)>
<!ATTLIST code language (#PCDATA)>
The file "rpc-method.dtd" that comes with the distribution has some commentary in addition to the actual
specification.
A file is (for now) limited to one definition. This is started by the one of the opening tags
"<methoddef>", "<functiondef>" or "<proceduredef>". This is followed by exactly one "<name>" container
specifying the method name, an optional version stamp, an optional hide-from-introspection flag, one or
more "<signature>" containers specifying signatures, an optional "<help>" container with the help text,
then the "<code>" container with the actual program code. All text should use entity encoding for the
symbols:
& C<&> (ampersand)
E<lt> C<<> (less-than)
E<gt> C<>> (greater-than)
The parsing process within the server class will decode the entities. To make things easier, the tool
scans all text elements and encodes the above entities before writing the file.
The Specification of Code
This is not "Programming 101", nor is it "Perl for the Somewhat Dim". The code that is passed in via one
of the "*.xpl" files gets passed to "eval" with next to no modification (see below). Thus, badly-written
or malicious code can very well wreak havoc on your server. This is not the fault of the server code. The
price of the flexibility this system offers is the responsibility on the part of the developer to ensure
that the code is tested and safe.
Code itself is treated as verbatim as possible. Some edits may occur on the server-side, as it make the
code suitable for creating an anonymous subroutine from. The make_method tool will attempt to use a
"CDATA" section to embed the code within the XML document, so that there is no need to encode entities or
such. This allows for the resulting *.xpl files to be syntax-testable with "perl -cx". You can aid this
by ensuring that the code does not contain either of the two following character sequences:
]]>
__DATA__
The first is the "CDATA" terminator. If it occurs naturally in the code, it would trigger the end-of-
section in the parser. The second is the familiar Perl token, which is inserted so that the remainder of
the XML document does not clutter up the Perl parser.
EXAMPLES
The RPC::XML distribution comes with a number of default methods in a subdirectory called (cryptically
enough) "methods". Each of these is expressed as a set of ("*.base", "*.code", "*.help") files. The
Makefile.PL file configures the resulting Makefile such that these are used to create "*.xpl" files using
this tool, and then install them.
DIAGNOSTICS
Most problems come out in the form of error messages followed by an abrupt exit.
EXIT STATUS
The tool exits with a status of 0 upon success, and 255 otherwise.
CAVEATS
I don't much like this approach to specifying the methods, but I liked my other ideas even less.
BUGS
Please report any bugs or feature requests to "bug-rpc-xml at rt.cpan.org", or through the web interface
at <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.
SUPPORT
• RT: CPAN's request tracker
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=RPC-XML>
• AnnoCPAN: Annotated CPAN documentation
<http://annocpan.org/dist/RPC-XML>
• CPAN Ratings
<http://cpanratings.perl.org/d/RPC-XML>
• Search CPAN
<http://search.cpan.org/dist/RPC-XML>
• Source code on GitHub
<http://github.com/rjray/rpc-xml>
LICENSE AND COPYRIGHT
This module and the code within are released under the terms of the Artistic License 2.0
(http://www.opensource.org/licenses/artistic-license-2.0.php). This code may be redistributed under
either the Artistic License or the GNU Lesser General Public License (LGPL) version 2.1
(http://www.opensource.org/licenses/lgpl-2.1.php).
SEE ALSO
RPC::XML, RPC::XML::Server
CREDITS
The XML-RPC standard is Copyright (c) 1998-2001, UserLand Software, Inc. See <http://www.xmlrpc.com> for
more information about the XML-RPC specification.
AUTHOR
Randy J. Ray <rjray@blackperl.com>