Frontier::Responder(3pm)				User Contributed Perl Documentation				  Frontier::Responder(3pm)

NAME

       Frontier::Responder - Create XML-RPC listeners for normal CGI processes

SYNOPSIS

	use Frontier::Responder;
	my $res = Frontier::Responder->new( methods => {
							add => sub{ $_[0] + $_[1] },
							cat => sub{ $_[0] . $_[1] },
						       },
					   );
	print $res->answer;

DESCRIPTION

       Use Frontier::Responder whenever you need to create an XML-RPC listener using a standard CGI interface. To be effective, a script using
       this class will often have to be put a directory from which a web server is authorized to execute CGI programs. An XML-RPC listener using
       this library will be implementing the API of a particular XML-RPC application. Each remote procedure listed in the API of the user defined
       application will correspond to a hash key that is defined in the "new" method of a Frontier::Responder object. This is exactly the way
       Frontier::Daemon works as well.	In order to process the request and get the response, the "answer" method is needed. Its return value is
       XML ready for printing.

       For those new to XML-RPC, here is a brief description of this protocol.	XML-RPC is a way to execute functions on a different machine. Both
       the client's request and listeners response are wrapped up in XML and sent over HTTP. Because the XML-RPC conversation is in XML, the
       implementation languages of the server (here called a listener), and the client can be different. This can be a powerful and simple way to
       have very different platforms work together without acrimony. Implicit in the use of XML-RPC is a contract or API that an XML-RPC listener
       implements and an XML-RPC client calls. The API needs to list not only the various procedures that can be called, but also the XML-RPC
       datatypes expected for input and output. Remember that although Perl is permissive about datatyping, other languages are not.
       Unforuntately, the XML-RPC spec doesn't say how to document the API. It is recomended that the author of a Perl XML-RPC listener should at
       least use POD to explain the API.  This allows for the programmatic generation of a clean web page.

METHODS

       new( OPTIONS )
	   This is the class constructor. As is traditional, it returns a blessed reference to a Frontier::Responder object. It expects arguments
	   to be given like a hash (Perl's named parameter mechanism).	To be effective, populate the "methods" parameter with a hashref that has
	   API procedure names as keys and subroutine references as values. See the SYNOPSIS for a sample usage.

       answer()
	   In order to parse the request and execute the procedure, this method must be called. It returns a XML string that contains the
	   procedure's response. In a typical CGI program, this string will simply be printed to STDOUT.

SEE ALSO

       perl(1), Frontier::RPC2(3)

       <http://www.scripting.com/frontier5/xml/code/rpc.html>

AUTHOR

       Ken MacLeod <ken@bitsko.slc.ut.us> wrote the underlying RPC library.

       Joe Johnston <jjohn@cs.umb.edu> wrote an adaptation of the Frontier::Daemon class to create this CGI XML-RPC listener class.

perl v5.10.1							    2002-08-03						  Frontier::Responder(3pm)