#
#--
# 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.
#++
#
# $Id: definitions.rb 2725 2006-06-02 13:26:32Z jmettraux $
#

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

require 'openwfe/expressions/condition'
require 'openwfe/expressions/flowexpression'


module OpenWFE

    #
    # This expression cancels the current process instance. Use with care.
    #
    #     <sequence>
    #         <participant ref="before" />
    #         <cancel-process />
    #         <participant ref="after" />
    #     </sequence>
    #
    # the message "after" will never get printed.
    #
    # Use rather in scenarii like that one :
    #
    #     class TestDefinition1 < ProcessDefinition
    #         def make
    #             process_definition :name => "25_cancel", :revision => "1" do
    #                 sequence do
    #                     participant "customer"
    #                     _cancel_process :if => "${f:no_thanks} == true"
    #                     concurrence do
    #                         participant "accounting"
    #                         participant "logistics"
    #                     end
    #                 end
    #             end
    #         end
    #     end
    #
    # Note that the expression accepts an "if" attribute.
    #
    class CancelProcessExpression < FlowExpression
        include ConditionMixin

        names :cancel_process, :cancel_flow

        #
        # apply / reply

        def apply (workitem)

            conditional = eval_condition(:if, workitem, :unless)
                #
                # for example : <cancel-process if="${approved} == false"/>

            return reply_to_parent(workitem) \
                if conditional == false

            #
            # else, do cancel the process

            get_expression_pool.cancel_process self

            # no need to reply to parent
        end

        #def reply (workitem)
        #end

    end

end