#
#--
# Copyright (c) 2007-2008, John Mettraux, OpenWFE.org
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions are met:
# 
# . Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.  
# 
# . Redistributions in binary form must reproduce the above copyright notice, 
#   this list of conditions and the following disclaimer in the documentation 
#   and/or other materials provided with the distribution.
# 
# . Neither the name of the "OpenWFE" nor the names of its contributors may be
#   used to endorse or promote products derived from this software without
#   specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.
#++
#

#
# "made in Japan"
#
# John Mettraux at openwfe.org
#

require 'soap/rpc/driver'

require 'openwfe/participants/participant'


module OpenWFE

    #
    # Wrapping a simple web service call within an OpenWFEru participant.
    #
    #     quote_service = OpenWFE::SoapParticipant.new(
    #         "http://services.xmethods.net/soap",        # service URI
    #         "urn:xmethods-delayed-quotes",              # namespace
    #         "getQuote",                                 # operation name
    #         [ "symbol" ])                               # param arrays (workitem fields)
    #     
    #     engine.register_participant("quote_service", quote_service)
    #
    # By default, call params for the SOAP operations are determined by
    # iterating the parameters and fetching the values under the 
    # corresponding workitem fields.
    # This behaviour can be changed by overriding the prepare_call_params()
    # method.
    # 
    # On the return side, you can override the method handle_call_result 
    # for better mappings between web service calls and the workitems.
    #
    class SoapParticipant 
        include LocalParticipant

        def initialize \
            (endpoint_url, namespace, method_name, params, param_prefix="")

            super()

            @driver = SOAP::RPC::Driver.new(endpoint_url, namespace)

            @method_name = method_name
            @params = params
            @param_prefix = param_prefix

            @driver.add_method(method_name, *params)
        end

        #
        # The method called by the engine when the flow reaches an instance
        # of this Participant class.
        #
        def consume (workitem)

            call_params = prepare_call_params(workitem)

            call_result = @driver.send(@method_name, *call_params)

            handle_call_result(call_result, workitem)

            reply_to_engine(workitem)
        end

        #
        # The base implementation : assumes that for each webservice operation
        # param there is a workitem field with the same name.
        #
        # Feel free to override this method.
        #
        def prepare_call_params (workitem)

            @params.collect do |param|
                get_param workitem, param
            end
        end

        #
        # This implementation simply stuffs the result into the workitem
        # as an attribute named "__result__".
        #
        # Feel free to override this method.
        #
        def handle_call_result (result, workitem)

            workitem.attributes["__result__"] = result
        end

        protected

            def get_param (workitem, param_name)

                param_name = @param_prefix + param_name if @param_prefix

                workitem.attributes[param_name] || ""
            end

    end

end