oracular (3) SOAP::Server.3pm.gz
NAME
SOAP::Server - provides the basic framework for the transport-specific server classes to build upon
DESCRIPTION
The SOAP::Server class provides the basic framework for the transport-specific server classes to build
upon. Note that in none of the code examples provided with SOAP::Lite is this class used directly.
Instead, it is designed to be a superclass within more specific implementation classes. The methods
provided by SOAP::Server itself are:
METHODS
new(optional key/value pairs)
$server = SOAP::Server->new(%options);
Creates a new object of the class. Various default instance values are set up, and like many of the
constructors in this module, most of the class methods described here may be passed in the
construction call by giving the name followed by the parameter (or an array reference if there are
multiple parameters).
action(optional new value)
$action = $server->action
Retrieves or sets the value of the action attribute on the server object. This attribute is used when
mapping the request to an appropriate namespace or routine. For example, the HTTP library sets the
attribute to the value of the SOAPAction header when processing of the request begins, so that the
find_target method described later may retrieve the value to match it against the server's
configuration. Returns the object itself when setting the attribute.
myuri(optional new value)
$server->myuri("http://localhost:9000/SOAP");
Gets or sets the myuri attribute. This specifies the specific URI that the server is answering
requests to (which may be different from the value specified in action or in the SOAPAction header).
serializer(optional new value)
deserializer(optional new value)
$serializer = $server->serializer;
$server->deserializer($new_deser_obj);
As with the client objects, these methods provide direct access to the serialization and
deserialization objects the server object uses to transform input and output from and to XML. There
is generally little or no need to explicitly set these to new values.
options(optional new value)
$server->options({compress_threshold => 10000});
Sets (or retrieves) the current server options as a hash-table reference. At present, only one
option is used within the SOAP::Lite libraries themselves:
compress_threshold
The value of this option is expected to be a numerical value. If set, and if the Compress::Zlib
library is available to use, messages whose size in bytes exceeds this value are compressed for
transmission. Both ends of the conversation have to support this and have it enabled.
Other options may be defined and passed around using this mechanism. Note that setting the options
using this accessor requires a full hash reference be passed. To set just one or a few values,
retrieve the current reference value and use it to set the key(s).
dispatch_with(optional new value)
$server->dispatch_with($new_table);
Represents one of two ways in which a SOAP::Server (or derived) object may specify mappings of
incoming requests to server-side subroutines or namespaces. The value of the attribute is a hash-
table reference. To set the attribute, you must pass a new hash reference. The hash table's keys are
URI strings (literal URIs or the potential values of the SOAPAction header), and the corresponding
values are one of a class name or an object reference. Requests that come in for a URI found in the
table are routed to the specified class or through the specified object.
dispatch_to(optional list of new values)
$server->dispatch_to($dir, 'Module', 'Mod::meth');
This is the more traditional way to specify modules and packages for routing requests. This is also
an accessor, but it returns a list of values when called with no arguments (rather than a single
one). Each item in the list of values passed to this method is expected to be one of four things:
Directory path
If the value is a directory path, all modules located in that path are available for remote use.
Package name
When the value is a package name (without including a specific method name), all routines within
the package are available remotely.
Fully qualified method name
Alternately, when the value is a package-qualified name of a subroutine or method, that specific
routine is made available. This allows the server to make selected methods available without
opening the entire package.
Object reference
If the value is an object reference, the object itself routes the request.
The list of values held by the dispatch_to table are compared only after the URI mapping table
from the dispatch_with attribute has been consulted. If the request's URI or SOAPAction header
don't map to a specific configuration, the path specified by the action header (or in absence,
the URI) is converted to a package name and compared against this set of values.
objects_by_reference(optional list of new values)
$server->objects_by_reference(qw(My:: Class));
This also returns a list of values when retrieving the current attribute value, as opposed to a
single value.
This method doesn't directly specify classes for request routing so much as it modifies the behavior
of the routing for the specified classes. The classes that are given as arguments to this method are
marked to be treated as producing persistent objects. The client is given an object representation
that contains just a handle on a local object with a default persistence of 600 idle seconds. Each
operation on the object resets the idle timer to zero. This facility is considered experimental in
the current version of SOAP::Lite.
A global variable/"constant" allows developers to specify the amount of time an object will be
persisted. The default value is 600 idle seconds. This value can be changed using the following code:
$SOAP::Constants::OBJS_BY_REF_KEEPALIVE = 1000;
on_action(optional new value)
$server->on_action(sub { ...new code });
Gets or sets the reference to a subroutine that is used for executing the on_action hook. Where the
client code uses this hook to construct the action-request data (such as for a SOAPAction header),
the server uses the on_action hook to do any last-minute tests on the request itself, before it gets
routed to a final destination. When called, the hook routine is passed three arguments:
action
The action URI itself, retrieved from the action method described earlier.
method_uri
The URI of the XML namespace the method name is labeled with.
method_name
The name of the method being called by the request.
on_dispatch(optional new value)
($uri, $name) = $server->on_dispatch->($request);
Gets or sets the subroutine reference used for the on_dispatch hook. This hook is called at the start
of the request-routing phase and is given a single argument when called:
request
An object of the SOAP::SOM class, containing the deserialized request from the client.
find_target
($class, $uri, $name) = $server->find_target($req)
Taking as its argument an object of the SOAP::SOM class that contains the deserialized request, this
method returns a three-element list describing the method that is to be called. The elements are:
class
The class into which the method call should be made. This may come back as either a string or an
objectreference, if the dispatching is configured using an object instance.
uri The URN associated with the request method. This is the value that was used when configuring the
method routing on the server object.
name
The name of the method to call.
handle
$server->handle($request_text);
Implements the main functionality of the serving process, in which the server takes an incoming
request and dispatches it to the correct server-side subroutine. The parameter taken as input is
either plain XML or MIME-encoded content (if MIME-encoding support is enabled).
make_fault
return $server->makefault($code, $message);
Creates a SOAP::Fault object from the data passed in. The order of arguments is: code, message,
detail, actor. The first two are required (because they must be present in all faults), but the last
two may be omitted unless needed.
SOAP::Server::Parameters
This class provides two methods, but the primary purpose from the developer's point of view is to allow
classes that a SOAP server exposes to inherit from it. When a class inherits from the
SOAP::Server::Parameters class, the list of parameters passed to a called method includes the
deserialized request in the form of a SOAP::SOM object. This parameter is passed at the end of the
arguments list, giving methods the option of ignoring it unless it is needed.
The class provides two subroutines (not methods), for retrieving parameters from the SOAP::SOM object.
These are designed to be called without an object reference in the parameter list, but with an array
reference instead (as the first parameter). The remainder of the arguments list is expected to be the
list from the method-call itself, including the SOAP::SOM object at the end of the list. The routines may
be useful to understand if an application wishes to subclass SOAP::Server::Parameters and inherit from
the new class instead.
byNameOrOrder(order, parameter list, envelope)
@args = SOAP::Server::Parameters::byNameOrOrder ([qw(a b)], @_);
Using the list of argument names passed in the initial argument as an array reference, this routine
returns a list of the parameter values for the parameters matching those names, in that order. If
none of the names given in the initial array-reference exist in the parameter list, the values are
returned in the order in which they already appear within the list of parameters. In this case, the
number of returned values may differ from the length of the requested-parameters list.
byName(order, parameter list, envelope)
@args = SOAP::Server::Parameters::byName ([qw(a b c)], @_);
Acts in a similar manner to the previous, with the difference that it always returns as many values
as requested, even if some (or all) don't exist. Parameters that don't exist in the parameter list
are returned as undef values.
EXAMPLE
The following is an example CGI based Web Service that utilizes a Perl module that inherits from the
"SOAP::Server::Parameters" class. This allows the methods of that class to access its input by name.
#!/usr/bin/perl
use SOAP::Transport::HTTP;
SOAP::Transport::HTTP::CGI
->dispatch_to('C2FService')
->handle;
BEGIN {
package C2FService;
use vars qw(@ISA);
@ISA = qw(Exporter SOAP::Server::Parameters);
use SOAP::Lite;
sub c2f {
my $self = shift;
my $envelope = pop;
my $temp = $envelope->dataof("//c2f/temperature");
return SOAP::Data->name('convertedTemp' => (((9/5)*($temp->value)) + 32));
}
}
SEE ALSO
SOAP::SOM, SOAP::Transport::HTTP
ACKNOWLEDGEMENTS
Special thanks to O'Reilly publishing which has graciously allowed SOAP::Lite to republish and
redistribute large excerpts from Programming Web Services with Perl, mainly the SOAP::Lite reference
found in Appendix B.
COPYRIGHT
Copyright (C) 2000-2004 Paul Kulchenko. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
AUTHORS
Paul Kulchenko (paulclinger@yahoo.com) Randy J. Ray (rjray@blackperl.com) Byrne Reese (byrne@majordojo.com)