NAME

XML::Compile::SOAP::Daemon - SOAP accepting server (base class)

INHERITANCE

XML::Compile::SOAP::Daemon is extended by
  XML::Compile::SOAP::Daemon::AnyDaemon
  XML::Compile::SOAP::Daemon::CGI
  XML::Compile::SOAP::Daemon::NetServer
  XML::Compile::SOAP::Daemon::PSGI

SYNOPSIS

#### have a look in the examples directory!
use XML::Compile::SOAP::Daemon::CGI;
my $daemon  = XML::Compile::SOAP::Daemon::CGI->new;

# operation definitions from WSDL
my $wsdl    = XML::Compile::WSDL11->new(...);
$wsdl->importDefinitions(...); # more schemas
$daemon->operationsFromWSDL($wsdl, callbacks => ...);

$daemon->setWsdlResponse($wsdl_fn);
$daemon->setWsdlResponse($wsdl_fn, $soap11->mediaType);

# operation definitions added manually
my $soap11  = XML::Compile::SOAP11::Server->new(schemas => $wsdl->schemas);
my $handler = $soap11->compileHandler(...);
$daemon->addHandler('getInfo', $soap11, $handler);

DESCRIPTION

This base class implements the common needs between various types of SOAP daemons. Ache daemon can handle various kinds of SOAP protocols at the same time, when possible hidden from the user of this module.

The following extensions are implemented on the moment:

XML::Compile::SOAP::Daemon::AnyDaemon, for transport over HTTP based on Any::Daemon (a generic pre-forked daemon) and LWP. It uses Log::Report as exception and loggin frame-work, just as all XML::Compile modules do, hence cleaner integration.
XML::Compile::SOAP::Daemon::CGI, for transport over HTTP based on CGI and LWP.
XML::Compile::SOAP::Daemon::PSGI allows to run SOAP server as a part of larger PSGI application (mixing webservice with standard webserver) or to integrate with existing event loop framework (AnyEvent, Coro, POE).
XML::Compile::SOAP::Daemon::NetServer, for transport over HTTP based on Net::Server and LWP. The Net::Server distribution offers a number of very different daemon implementations. There are too many ways to configure it.

If you have a WSDL describing your procedures (operations), then the only thing you have to worry about is adding callbacks for each of the defined ports. Without WSDL, you will need to do more manually, but it is still relatively simple to achieve.

Do not forget to take a look at the extensive example, enclosed in the XML::Compile::SOAP::Daemon distribution package. It is really worth the time.

METHODS

Constructors

XML::Compile::SOAP::Daemon->new(%options)

-Option            --Default
 accept_slow_select  <true>
 output_charset      'UTF-8'
 soap_action_input   {}
 wsa_action_input    {}
 wsa_action_output   {}

accept_slow_select => BOOLEAN

Traditional SOAP does not have a simple way to find out which operation is being called. The only way to determine which operation is needed, is by trying all defined operations until one matches.

Later, people started to use the soapAction HTTP header (which was officially only for proxies) and then the WSA SOAP header extension. Either of them make it easy to determine the right handler one on one.

Disabling accept_slow_select will protect you against various forms of DoS-attacks, however this is often not possible as many WSDLs do not define soapAction or WSA action keys.

output_charset => STRING

The character-set to be used for the output XML document.

soap_action_input => HASH|ARRAY

The keys are port names, with as value the related SOAPAction header field content (without quotes). Often, these SOAPAction fields originate from the WSDL.

wsa_action_input => HASH|ARRAY

The keys are port names, the values are strings which are used by clients to indicate which server operation they want to use. Often, an WSDL contains this information in wsaw:Action attributes; that info is added to this HASH automatically when XML::Compile::SOAP::WSA is loaded.

wsa_action_output => HASH|ARRAY

The keys are port names, the values are strings which the server will add to replies to the client. Often, an WSDL contains this information in wsaw:Action attributes; that info is added to this HASH automatically when XML::Compile::SOAP::WSA is loaded.

Attributes

$obj->addSoapAction(HASH|PAIRS): Map SOAPAction headers only operations. You do not need to map explicitly when the info can be derived from the WSDL.
$obj->addWsaTable( <'INPUT'|'OUTPUT'>, [HASH|PAIRS] ): Map operation name onto respectively server-input or server-output messages, used for wsa:Action fields in the header. Usually, these values are automatically taken from the WSDL (but only if the WSA extension is loaded).
$obj->outputCharset(): The character-set to be used for output documents.

Running the server

$obj->process($client, $xmlin, $request, $action)

This method is called to process a single request. The $xmlin is a SOAP-structured message (an XML::LibXML::Element, XML::LibXML::Document, or XML as string), was received from the $client (some extension specific object).

The full $request is passed in, however its format depends on the kind of server. The $action parameter relates to the soapAction header field which may be available in some form.

Returned is an XML document (XML::LibXML::Document) as answer or a protocol specific ready response object (usually an error object).

This process method will determine which callback routine to use to generate a reply and then call the routine. See "Operation handlers" for details on how the routines are called.

See operationsFromWSDL() and addHandler() on how the callback routines can be specified. See new() for a description of the options which control how the callback routine is chosen.

$obj->run(%options)

How the daemon is run depends much on the extension being used. See the ::NetServer and ::CGI manual-page.

Preparations

$obj->addHandler($name, $soap, CODE)

The $soap value is SOAP11, SOAP12, or a $soap server object or and $soap Operation object. The CODE reference is called with the incoming document (an XML::LibXML::Document) of the received input message.

In case the handler does not understand the message, it should return undef. Otherwise, it must return a correct answer message as XML::LibXML::Document.

$obj->operationsFromWSDL($wsdl, %options)

Compile the operations found in the $wsdl object (an XML::Compile::WSDL11). You can add the operations from many different WSDLs into one server, simply by calling this method repeatedly.

You can also specify %options for XML::Compile::WSDL11 subroutine operations. Those parameters may be needed to distinguish between the test-server and the production server, provided protocol support and such.

The %options can also contain parameters for XML::Compile::SOAP::Operation subroutine compileHandler (and its SOAP11 and SOAP12 extensions), which in turn will pass it all over the place. For instance, you can pass interpret_nillable_as_optional.

-Option          --Default
 callbacks         {}
 default_callback  <produces fault reply>
 operations        undef

callbacks => HASH: The keys are the port names, as defined in the $wsdl. The values are CODE references which are called in case a message is received which is addressing the port (this is a guess). See "Operation handlers"
default_callback => CODE: When a message arrives which has no explicit handler attached to it, this handler will be called. By default, an "not implemented" fault will be returned. See "Operation handlers"
operations => ARRAY: Load the selected operations only (XML::Compile::SOAP::Operation objects) If not specified, all operations will be taken which are selected with the service, port, and binding %options for XML::Compile::WSDL11 subroutine operations.

example:

$daemon->operationsFromWSDL($wsdl, service => 'MyService',
   binding => 'MyService-soap11', callbacks => {get => \$f11});
$daemonwsdl->operationsFromWSDL($wsdl, service => 'MyService-test',
   binding => 'MyService-soap12', callbacks => {get => \$f12});

$obj->setWsdlResponse( $filename, [$filetype] )

Many existing SOAP servers will response to GET queries which end on "?WSDL" by sending the WSDL in use by the service.

The default $filetype is application/wsdl+xml. You may need text/xml

Helpers

$obj->faultInvalidXML($error)

$obj->faultNotSoapMessage($nodetype)

$obj->faultUnsupportedSoapVersion($env_ns)

Produces a text message, because we do not know how to produce an error in a SOAP which we do not understand.

$obj->handlers( <'SOAP11'|'SOAP12'|$soap> )

Returns all the handler names for a certain soap version.

example:

foreach my $version (sort $server->soapVersions)
{   foreach my $action (sort $server->handlers($version))
    {  print "$version $action\n";
    }
}

$obj->printIndex( [$fh] )

Print a table which shows the messages that the server can handle, by default to STDOUT.

$obj->soapVersions()

DETAILS

Operation handlers

Per operation, you define a callback which handles the request. There can also be a default callback for all your operations. Besides, when an operation does not have a handler defined, one is created for you.

sub my_callback($$$)
{   my ($soap, $data_in, $request) = @_;

    return $data_out;
}

The $soap parameter is the actual XML::Compile::SOAP object which handles this protocol version (at the moment only XML::Compile::SOAP11. $data_in is a HASH with the decoded information from the request. The type and content of $request depends on the type of server, often an HTTP::Request.

The $data_out is a nested HASH which will be translated in the right XML structure. This could be a Fault, like shown in the next section.

Please take a look at the scripts in the examples/ directory within the distribution.

Returning errors

In WSDLs you may find explicitly defined error details types. There is only one such error structure per operation: when an operation may return different kinds of errors, they will be wrapped into one structure which contains the details. See section "Returning private errors" below.

Errors which do not return an details record can always be reported with code and string. Let's first explain those.

Returning general errors

To have a handler return an error, leave the callback with something like this:

use XML::Compile::Util        qw/pack_type/;

sub my_callback($$)
{   my ($soap, $data) = @_;

    my $code = pack_type $my_err_ns, 'error-code';

    return
     +{ Fault =>
         { faultcode   => $code
         , faultstring => 'something is wrong'
         , faultactor  => $soap->role
         }
      , _RETURN_CODE => 404
      , _RETURN_TEXT => 'sorry, not found'
      };
}

Fault codes are "prefix:error-name", XML::Compile finds the right prefix based on the URI. If your error namespace is not mentioned in the WSDL or other loaded schemas, you should use XML::Compile::WSDL11 subroutine prefixes first.

SOAP uses error codes in the SOAPENV namespace. It shows whether errors are client or server side. This is produced like:

use XML::Compile::SOAP::Util 'SOAP11ENV';
$code = pack_type SOAP11ENV, 'Server.validationFailed';

[release 2.02] Fields _RETURN_CODE and _RETURN_TEXT can be used to change the HTTP response (and maybe other protocol headers in the future). These can also be used with valid answers, not limited to errors. There is no clear definition how SOAP faults and HTTP return codes should work together for user errors.

Be warned that WCF (MicroSoft's .NET) interprets the return code in SOAP1.2 style, not SOAP1.1. The 1.2 specification says that only _RETURN_CODE 200 and 202 can contain a SOAP respons. Other servers will code the content for any 2xx code.

Returning private errors

In a WSDL, we can specify own fault types. These defined elements describe the detail component of the message.

For example, in the WSDL and Schema we may have:

<xs:element name="errorReportMsg" type="ErrorReportType"/>
<xs:complexType name="ErrorReportType">
  <xs:sequence>
    <xs:element name="info" type="string">
    <xs:element name="cause" type="string" minOccurs="0">
  </xs:sequence>
</xs:complexType>

<message name="ErrorReport">
    <part name="message" element="tmdd:errorReportMsg"/>
</message>

<operation name="GetData">
  <input message="GetDataRequest"/>
  <output message="GetDataRequest"/>
  <fault name="errorReport" message="ErrorReport"/>
</operation>

To return a private error you need to determine the name of the fault part. In the example above the fault parts name is errorReport. However, in some WSDLs the name option is not present and XML::Compile::SOAP assumes that fault will be used to indicate the fault part.

You need to return a HASH with values for the ErrorReport element together with values for the fields in the Fault value shown in the previous section. For example:

my $msg = "Unknown Error";
return
 +{ errorReport =>   # the name of the fault part
      { # this gets put into the 'detail' part of
        # the fault message
        info => $msg

        # these are used for the other parts of the fault message
      , faultcode   => pack_type(SOAP11ENV, 'Server.BadOperation')
      , faultstring => $msg
      , faultactor  => $soap->role
      }
  };

If no name is specified for the fault part, then you can use:

return
 +{ fault =>   # the name of the fault part
      { faultcode   => pack_type(SOAP11ENV, 'Server.BadOperation')
      , faultstring => $msg
      , faultactor  => $soap->role
      , detail => { info=> $msg }
      }
  };

It has been observed that several SOAP toolkits do not handle user defined faults messages very well. However, they do provide the faultcode and faultstring values from the fault message.

LICENSE

Copyrights 2007-2022 by [Mark Overmeer <markov@cpan.org>]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://dev.perl.org/licenses/

To install XML::Compile::SOAP::Daemon, copy and paste the appropriate command in to your terminal.

cpanm

cpanm XML::Compile::SOAP::Daemon

CPAN shell

perl -MCPAN -e shell
install XML::Compile::SOAP::Daemon

For more information on module installation, please visit the detailed CPAN module installation guide.

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