Evangelo Prodromou > JOAP-0.01 > JOAP::Proxy::Package::Server

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NAME ^

JOAP::Proxy::Package::Server -- Base Class for Proxies of JOAP Server

SYNOPSIS ^

  # define the package

  package MyProxyServer;
  use JOAP::Proxy::Package::Server;
  use base qw(JOAP::Proxy::Package::Server);

  # define remote address

  MyProxyServer->Address('joap-server.example.net');

  # define local classes for classes on server

  MyProxyServer->ClassProxy({Person => MyProxy::Person,
                             Foo => MyProxy::Foo});

  1;

  package main;

  # Get a Jabber connection (you're responsible for this)

  my $con = get_net_jabber_connection_somehow();

  # Set it for all the proxies

  JOAP::Proxy->Connection($con);

  # initialize the server

  my $server = MyProxyServer->get;

  # read an attribute

  my $foo = $server->logLevel;

  # set an attribute

  $server->logLevel(14);

  # save changed values

  $server->save;

  # refresh attributes from the remote server

  $server->refresh;

  # determine which local class represents a remote class

  my $local = $server->proxy_class('Person@joap-server.example.net');

ABSTRACT ^

This module provides an abstract base class that can be used to create JOAP object server classes. These classes store metadata about the object server in the package, making things a little more efficient.

DESCRIPTION ^

The benefit of using a package to store object server metadata is kinda moot, since there's going to be a small (preferably singleton) number of instances anyways.

The main benefit is that the code generator, joappxgen, can put the metadata in the package for you, saving a round-trip to the server for each program invocation. Note that setting up the metadata is a little tricky and error prone; if you set it up by hand, make sure you get all the metadata, or you'll have weird errors. If in doubt, just put in the Address and ClassMap.

Additionally, it lets you map local Perl modules to remote classes.

Note that you don't have to use the remote object server if you don't want to. You can just talk directly to its classes and instances.

The Perl methods are very similar to those for other JOAP::Proxy packages, but they are listed here for completeness.

As a usage note, you should set the Connection class attribute of the JOAP::Proxy class before using any of the methods in this package (except maybe Address). See JOAP::Proxy for more information.

Instance Methods

refresh

Read the attributes of this remote object server and store them locally in the instance. The attributes can then be queried using the autoloaded accessors.

save

Save the local values of attributes to the remote instance. This will only save writable attributes.

proxy_class($classaddress)

Return the local proxy class that proxies for the remote class at address $classaddress. The class will also be initialized with its class metadata and attribute values.

See JOAP::Addresses for the acceptable values of a class address.

Class Methods

Most of the class methods are concerned with setting and getting metadata.

Address()
Address($address)

The address of the remote object server this class is a proxy for. This is the only introspection method application code should use as a mutator. It's mostly useful when several object servers at different locations use the same interface; you can say which one you're interested in by changing the address.

See JOAP::Addresses for the acceptable values of an object server address.

Attributes
attributes

Returns a reference to a hashtable mapping attribute names to attribute descriptors. See JOAP::Descriptors for more information on these data structures.

Methods
methods

Returns a reference to a hashtable mapping method names to method descriptors. See JOAP::Descriptors for more information on these data structures.

Timestamp
timestamp

The date and time that the object server structure description was downloaded from the remote class. It's in ISO 8601 format; see JOAP::Types for details.

Note that this is also used internally as a flag to indicate that the object server structure has been downloaded at all. If you set this attribute, without setting all the other introspection attributes, bad things will most definitely occur.

Description
description

A human-readable general description of the purpose and behavior of the class.

Classes
classes

A reference to a list of addresses of remote classes that are served by this object server.

ClassMap

A reference to a hashtable mapping the class name ('Person', not 'Person@joap-server.example.net') of a remote class to the package name of a local class that acts as its proxy.

accessor($name)

Returns a closure which would make a good accessor for attribute $name. This is used by the code generator like this:

    *foo = MyServerProxy->accessor('foo');
method($name)

Returns a closure which would make a good local method for the remote method $name. This is used by the code generator like this:

    *bar = MyServerProxy->method('bar');

Autoloaded Methods

As with other JOAP::Proxy packages, you can just go blithely around using accessors, mutators, and remote methods of the remote class or instance without really having to write any code for them.

For attributes, an eponymous ("same named") accessor will be created that will return the value of the attribute.

    my $logLevel = $server->logLevel;

If the attribute is writable, the same local method can be used as a mutator by passing a single value as the argument to the method.

    $server->logLevel(7);

For remote methods, an eponymous local method is created that takes the same arguments and has the same return type as the remote method. This works for both class and instance methods.

    $server->log('Added item foo.');

    my $new_value = $server->logLine(339);

There's no problems with class versus instance methods or attributes with this package, as with JOAP::Proxy::Package::Class; all methods and accessors should be called on the server instance.

Note that if there are remote methods or attributes that have the same name as one of the above built-in methods, they won't work. Similarly, if a remote method and a remote attribute have the same name, the remote method will be used.

There are also some internal methods that may cause interference with remote methods and attributes.

EXPORT ^

None by default.

BUGS ^

I'm not entirely satisfied with how this class works. I think it should update the addresses of classes in the classmap when its address is updated.

The whole storing-metadata-in-a-package thing is only so useful unless you use the code generator.

It's not a highlander class.

If the address of the server is updated, it doesn't automatically update the addresses of proxy classes in the classmap.

SEE ALSO ^

If you have no clue what all this stuff is about, you should check out the JOAP package.

This is more useful if you generate the code using joappxgen, the code generator.

You should also probably use it in conjunction with JOAP::Proxy::Package::Class, especially in your ClassMap.

If you just need a one-off server instance, and you don't want to create a package for it, you should try JOAP::Proxy::Server.

You should see JOAP::Proxy for info on how the Connection class attribute works.

More info about how to contact the author can be found in the JOAP documentation.

AUTHOR ^

Evan Prodromou <evan@prodromou.san-francisco.ca.us>

COPYRIGHT AND LICENSE ^

Copyright (c) 2003, Evan Prodromou <evan@prodromou.san-francisco.ca.us>.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

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