NAME Catalyst::Plugin::Server::JSONRPC -- Catalyst JSONRPC Server Plugin SYNOPSIS package MyApp; use Catalyst qw/Server Server::JSONRPC/; package MyApp::Controller::Example; use base 'Catalyst::Controller'; sub echo : JSONRPC { # available as: example.echo my ( $self, $c, @args ) = @_; $c->stash->{jsonrpc} = join ', ', @args; } sub ping : JSONRPCPath('/ping') { # available as: ping my ( $self, $c ) = @_; $c->stash->{jsonrpc} = 'Pong'; } sub world : JSONRPCRegex(/hello/) { # available as: *hello* my ($self, $c) = @_; $c->stash->{jsonrpc} = 'World'; } sub echo : JSONRPCLocal { # available as: example.echo my ( $self, $c, @args ) = @_; $c->stash->{jsonrpc} = join ', ', @args; } sub ping : JSONRPCGlobal { # available as: ping my ( $self, $c ) = @_; $c->stash->{jsonrpc} = 'Pong'; } DESCRIPTION JSONRPC Plugin for Catalyst which we tried to make compatible with the way Catalyst works with URLS. Main features are: * Split JSONRPC methodNames by STRING to find out Controller. * Single entrypoint for JSONRPC calls, like http://host.tld/rpc * DispatchTypes (attributes) which work much the same as Catalyst attrs * JSONRPC Parameter handling transparent to Catalyst parameter handling HOW IT WORKS The default behaviour will handle JSONRPC Requests sent to "/rpc" by creating an OBJECT containing JSONRPC specific parameters in "$c->req->jsonrpc". Directly after, it will find out the Path of the Action to dispatch to, by splitting methodName by ".": methodName: hello.world path : /hello/world From this point, it will dispatch to '/hello/world' when it exists, like Catalyst Urls would do. What means: you will be able to set Regexes, Paths etc on subroutines to define the endpoint. We discuss these custom JSONRPC attributes below. When the request is dispatched, we will return $c->stash->{jsonrpc} to the jsonrpc client, or, when it is not available, it will return $c->stash to the client. There is also a way of defining $c->stash keys to be send back to the client. ATTRIBUTES You can mark any method in your Catalyst application as being available remotely by using one of the following attributes, which can be added to any existing attributes, except Private. Remember that one of the mentioned attributes below are automatically also Privates... JSONRPC Make this method accessible via JSONRPC, the same way as Local does when using catalyst by URL. The following example will be accessible by method "hello.world": package Catalyst::Controller::Hello sub world : JSONRPC {} JSONRPCLocal Identical version of attribute "JSONRPC" JSONRPCGlobal Make this method accessible via JSONRPC, the same way as GLOBAL does when using catalyst by URL. The following example will be accessible by method "ping": package Catalyst::Controller::Hello sub ping : JSONRPCGlobal {} JSONRPCPath('/say/hello') Make this method accessible via JSONRPC, the same way as Path does when using catalyst by URL. The following example will be accessible by method "say.hello": package Catalyst::Controller::Hello sub hello : JSONRPCPath('/say/hello') {} JSONRPCRegex('foo') Make this method accessible via JSONRPC, the same way as Regex does when using catalyst by URL. The following example will be accessible by example methods: "a.foo.method" "wedoofoohere" "foo.getaround" package Catalyst::Controller::Hello sub hello : JSONRPCPath('foo') {} ACCESSORS Once you've used the plugin, you'll have an $c->request->jsonrpc accessor which will return an "Catalyst::Plugin::Server::JSONRPC" object. You can query this object as follows: $c->req->jsonrpc->is_jsonrpc_request Boolean indicating whether the current request has been initiated via JSONRPC $c->req->jsonrpc->config Returns a "Catalyst::Plugin::Server::JSONRPC::Config" object. See the "CONFIGURATION" below on how to use and configure it. $c->req->jsonrpc->body The body of the original JSONRPC call $c->req->jsonrpc->method The name of the original method called via JSONRPC $c->req->jsonrpc->args A list of parameters supplied by the JSONRPC call $c->req->jsonrpc->result_as_string The JSON body that will be sent back to the JSONRPC client $c->req->jsonrpc->error Allows you to set jsonrpc fault code and message Server Accessors The following accessors are always available, whether you're in a jsonrpc specific request or not $c->server->jsonrpc->list_methods Returns a HASHREF containing the available jsonrpc methods in Catalyst as a key, and the "Catalyst::Action" object as a value. CATALYST REQUEST To make things transparent, we try to put JSONRPC params into the Request object of Catalyst. But first we will explain something about the JSONRPC specifications. A full draft of these specifications can be found on: "http://www.jsonrpc.com/spec" In short, a jsonrpc-request consists of a methodName, like a subroutine name, and a list of parameters. This list of parameters may contain strings (STRING), arrays (LIST) and structs (HASH). Off course, these can be nested. $c->req->arguments We will put the list of arguments into $c->req->arguments, thisway you can fetch this list within your dispatched-to-subroutine: sub echo : JSONRPC { my ($self, $c, @args) = @_; $c->log->debug($arg[0]); # Prints first JSONRPC parameter # to debug log } $c->req->parameters Because JSONRPC parameters are a LIST, we can't just fill $c->req->paremeters. To keep things transparent, we made an extra config option what tells the JSONRPC server we can assume the following conditions on all JSONRPC requests: - There is only one JSONRPC parameter - This JSONRPC parameter is a struct (HASH) We will put this STRUCT as key-value pairs into $c->req->parameters. $c->req->params Alias of $c->req->parameters $c->req->param Alias of $c->req->parameters INTERNAL JSONRPC FUNCTIONS The following system functions are available to the public., system.listMethods returns a list of available RPC methods. DEFINING RETURN VALUES The JSON-RPC response must contain a single parameter, which may contain an array (LIST), struct (HASH) or a string (STRING). To define the return values in your subroutine, you can alter $c->stash in three different ways. Defining $c->stash->{jsonrpc} When defining $c->stash->{jsonrpc}, the JSONRPC server will return these values to the client. When there is no $c->stash->{jsonrpc} When there is no "$c->stash->{jsonrpc}" set, it will return the complete "$c->stash" CONFIGURATION The JSONRPC Plugin accepts the following configuration options, which can be set in the standard Catalyst way (See "perldoc Catalyst" for details): Your::App->config( jsonrpc => { key => value } ); You can look up any of the config parameters this package uses at runtime by calling: $c->server->jsonrpc->config->KEY path This specifies the entry point for your jsonrpc server; all requests are dispatched from there. This is the url any JSONRCP client should post to. You can change this to any "Regex" wish. The default is: "qr!^(/?)rpc(/|$)!i", which matches on a top-level path begining with "rpc" preceeded or followed by an optional "/", like this: http://your-host.tld/rpc prefix This specifies the prefix of the forward url. For example, with a prefix of "rpc", and a method "foo", the forward path would be come "/rpc/foo". The default is '' (empty). separator This is a STRING used to split your method on, allowing you to use a hierarchy in your method calls. For example, with a separator of "." the method call "demo.echo" would be forwarded to "/demo/echo". To make "demo_echo" forward to the same path, you would change the separator to "_", The default is ".", splitting methods on a single "." convert_params Make the arguments in "$c->req->jsonrpc->params" available as "$c->req->params". Defaults to true. show_errors Make system errors in "$c->error" public to the rpc-caller in a JSON-RPC faultString. When show_errors is false, and your catalyst app generates a fault, it will return an JSON-RPC fault containing error number 500 and error string: "Internal Server Error". Defaults to false. DIAGNOSTICS Invalid JSONRPC request: No such method There is no corresponding method in your application that can be forwarded to. Invalid JSONRPC request %s There was an error parsing the JSONRPC request Invalid JSONRPC request: Unknown error An unexpected error occurred TODO Make error messages configurable/filterable Right now, whatever ends up on $c->error gets returned to the client. It would be nice to have a way to filter/massage these messages before they are sent back to the client. Make stash filterable before returning Just like the error messages, it would be nice to be able to filter the stash before returning so you can filter out keys you don't want to return to the client, or just return a certain list of keys. This all to make transparent use of JSONRPC and web easier. SEE ALSO Catalyst::Manual, Catalyst::Request, Catalyst::Response, JSON::RPC::Common, ACKNOWLEDGEMENTS For the original implementation of this module: Marcus Ramberg "mramberg@cpan.org" Christian Hansen Yoshinori Sano Jos Boumans (kane@cpan.org) Michiel Ootjers (michiel@cpan.org) AUTHORS Sergey Nosenko (darknos@cpan.org) http://code.google.com/p/catalyst-server-jsonrpc BUG REPORTS Please submit all bugs regarding "Catalyst::Plugin::Server::JSONRPC" to http://code.google.com/p/catalyst-server-jsonrpc/issues/entry LICENSE This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.