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make_method(1)





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 specify-
       ing 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.


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.

       --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 com-
           mand 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 specifed. 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 out-
           put 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 informa-
           tion. Each line of the file should look like one of the following:

           Name: SSTTRRIINNGG
               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: SSTTRRIINNGG
               Provide a version stamp for the function. If no line matching
               this pattern is present, no version tag will be written.

           Hidden: SSTTRRIINNGG
               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: SSTTRRIINNGG
               This line may appear more than once, and is treated cumula-
               tively. 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: SSTTRRIINNGG
               Specifies the file from which to read the help text. It is not
               an error if no help text is specified.

           Codefile: SSTTRRIINNGG
               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]: ssttrriinngg
               Specifies the file from which to read code, while also identi-
               fying the language that the code is in. This allows for the
               creation of a XPL file that includes multiple language imple-
               mentations 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, version?, hidden?, signature+,
                                    help?, code)>
           <!ELEMENT  methoddef  (name, version?, hidden?, signature+,
                                  help?, code)>
           <!ELEMENT  functiondef (name, version?, hidden?, signature+,
                                   help?, code)>
           <!ELEMENT  name       (#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 "<procedure-
       def>". 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<&amp;> (ampersand)
           E<lt> C<&lt;>  (less-than)
           E<gt> C<&gt;>  (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 ensur-
       ing that the code does not contain either of the two following charac-
       ter 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 Make-
       file.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.


CAVEATS

       I don't much like this approach to specifying the methods, but I liked
       my other ideas even less.


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.


LICENSE

       This module is licensed under the terms of the Artistic License that
       covers Perl itself. See <http://www.opensource.org/licenses/artis-
       tic-license.php> for the license itself.


SEE ALSO

       RPC::XML, RPC::XML::Server


AUTHOR

       Randy J. Ray <rjray@blackperl.com>

perl v5.8.8                       2006-02-18                    MAKE_METHOD(1)

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