NetSDS::App::JSRPC - JSON-RPC server framework
#!/usr/bin/env perl # JSON-RPC server use 5.8.0; use warnings; use strict; JServer->run(); 1; # Server application logic package JServer; use base 'NetSDS::App::JSRPC'; # This method is available via JSON-RPC sub sum { my ($self, $param) = @_; return $$param[0] + $$param[1]; } 1;
NetSDS::App::JSRPC module implements framework for common JSON-RPC based server application. JSON-RPC is a HTTP based protocol providing remote procudure call (RPC) functionality using JSON for requests and responses incapsulation.
NetSDS::App::JSRPC
This implementation is based on NetSDS::App::FCGI module and expected to be executed as FastCGI or CGI application.
Diagram of class inheritance:
[NetSDS::App::JSRPC] - JSON-RPC server | [NetSDS::App::FCGI] - CGI/FCGI application | [NetSDS::App] - common application | [NetSDS::Class::Abstract] - abstract class
Both request and response are JSON-encoded strings represented in HTTP protocol as data of 'application/json' MIME type.
To develop new JSON-RPC server application you need to create application class inherited from NetSDS::App::JSRPC:
It's just empty application:
#!/usr/bin/env perl JSApp->run( conf_file => '/etc/NetSDS/jsonapp.conf' ); package JSApp; use base 'NetSDS::App::JSRPC'; 1;
Alsoe you may want to add some specific code for application startup:
sub start { my ($self) = @_; connect_to_dbms(); query_for_external_startup_config(); do_other_initialization(); }
And of course you need to add methods providing necessary functions:
sub send_sms { my ($self, $params) = @_; return $self->{kannel}->send( from => $params{'from'}, to => $params{'to'}, text => $params{'text'}, ); } sub kill_smsc { my ($self, $params) = @_; # 1M of MT SM should be enough to kill SMSC! # Otherwise we call it unbreakable :-) for (my $i=1; $<100000000; $i++) { $self->{kannel}->send( %mt_sm_parameters, ); } if (smsc_still_alive()) { return $self->error("Can't kill SMSC! Need more power!"); } }
NetSDS::App::JSRPC module provides two methods that may be used to implement more complex logic than average RPC to one class.
By default it is just wrapper around UNIVERSAL::can function. However it may be rewritten to check for methods in other classes or even construct necessary methods on the fly.
UNIVERSAL::can
By default it just call local class method with the same name as in JSON-RPC call. Of course it can be overwritten and process query in some other way.
This code describes logic of call processing:
# It's not real code if (can_method($json_method)) { process_call($json_method, $json_params); }
For more details read documentation below.
It's internally used constructor that shouldn't be used from application directly.
This is internal method that implements JSON-RPC call processing.
This method allows to check if some method is available for execution. By default it use UNIVERSAL::can but may be rewritten to implement more complex calls dispatcher.
Paramters: method name (string)
Return true if method execution allowed, false otherwise.
Example:
# Rewrite can_method() to search in other class sub can_method { my ($self, $method) = @_; return Other::Class->can($method); }
Paramters: method name, parameters.
Returns parameters from executed method as is.
# Rewrite process_call() to use other class sub process_call { my ( $self, $method, $params ) = @_; return Other::Class->$method($params); }
Paramters: HTTP POST data as string
Returns: request method, parameters, id
This is internal method for encoding JSON-RPC response string.
Paramters:
Returns JSON encoded response message.
Internal method implementing JSON-RPC error response.
Returns JSON encoded error message
See samples/app_jsrpc.fcgi appliction.
samples/app_jsrpc.fcgi
JSON
JSON::RPC2
http://json-rpc.org/wiki/specification - JSON-RPC 1.0
http://groups.google.com/group/json-rpc/web/json-rpc-1-2-proposal - JSON-RPC 2.0
1. Move error codes to constants to provide more clear code.
2. Implement objects/classes support.
Michael Bochkaryov <misha@rattler.kiev.ua>
Copyright (C) 2008-2009 Net Style Ltd.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
To install NetSDS, copy and paste the appropriate command in to your terminal.
cpanm
cpanm NetSDS
CPAN shell
perl -MCPAN -e shell install NetSDS
For more information on module installation, please visit the detailed CPAN module installation guide.