SOAP::Lite Modules

Part:   1  2   3 

(Continued from previous part...)

SOAP::Transport::TCP Module

Let's look at one of the SOAP server API module first. SOAP::Transport::TCP has sub module called SOAP::Transport::TCP::Server. It offers two functionalites: 1. Taking SOAP requests as a SOAP server; 2. Interacting with application modules to handle the requests as a SOAP server side API.

Main functions of SOAP::Transport::TCP::Server are:

new(LocalAddr=>'hostname', LocalPort=>'port', Listen=>'queueSize') - Constructs and returns SOAP server object that listens on the specified host name at the specified port with the specified queue size.

dispatch_to('Module::method') - Defines the module name and the method name that can be called by the incoming SOAP request for this server, and returns this server object.

handle() - Puts this server in waiting mode for incoming SOAP request. Whenever a SOAP request comes, it will be automatically passed to the module name and the method name defined by the dispatch_to() function based on the SOAP action name in the request.

Here is a sample program to show you how to create a SOAP server with TCP as the transportation protocol:

#- SoapTcpServer.pl
#- Copyright (c) 2002 by Dr. Herong Yang
   use SOAP::Transport::TCP;
   my $daemon = SOAP::Transport::TCP::Server
      ->new(LocalAddr => 'localhost', LocalPort => 8001, Listen => 5);
   $daemon->dispatch_to('Hello::hello');
   print "SOAP TCP server listening...\n";
   print "   Host: ", $daemon->sockhost, "\n";
   print "   Port: ", $daemon->sockport, "\n";
   $daemon->handle();

This program will create a SOAP server on localhost at 8001, and dispatch SOAP request to Hello::hello, if the SOAP action name matches it. Here is my Hello module code:

#- Hello.pm
#- Copyright (c) 2002 by Dr. Herong Yang
   package Hello;
   sub hello {
     shift;
     return "Hello " . shift;
   }
1;

If you run SoapTcpServer.pl, you will get this:

SOAP TCP server listening...
   Host: 127.0.0.1
   Port: 8001

The SOAP server is ready. Now you need a SOAP client program to talk the SOAP server. See the next section to know how to write a SOAP client program.

SOAP::Lite Module

SOAP:Lite represents the SOAP client API that allows you to send a Perl function call as a SOAP request to the specified SOAP server, and receive the result of the call as a SOAP response from the server. Main functions of SOAP::Lite are:

new() - Constructs a new SOAP::Lite object, and returns it.

uri('uri') - Defines the URI (Universal Resource Identifier) of the target module to be called, and returns the same object.

proxy('url') - Defines the URL (Universal Resource Locator) of the SOAP server, and returns the same object.

'method'() - Allows to call the method from the target module on the SOAP server, and returns a new SOAP::SOM object representing the outcome of the call.

$som->result - A property of a SOAP::SOM object representing the returning scalar value of the call.

Here is a sample program to show you how to use SOAP::LITE module to request a function call to the SOAP server I created in the previous section.

#- SoapTcpClient.pl
#- Copyright (c) 2002 by Dr. Herong Yang
   use SOAP::Lite;
   # use SOAP::Lite +trace;
   my $client = SOAP::Lite->new();
   $client->uri('urn:Hello');
   $client->proxy('tcp://localhost:8001');
   my $som = $client->hello("Herong");
   my $output = $som->result;
   print $output . "\n";

Run it while the SoapTcpServer.pl is running, you will get:

Hello Herong

This is amazing. You can create a simple SOAP server and client in less than 20 lines of source code!

Note that the proxy URL must have "tcp" as the protocol name, since the SOAP server is running with TCP as the transportation protocol.

(Continued on next part...)

Part:   1  2   3