Class: OpenWFE::BlockParticipant

Inherits:

Object

• Object
• OpenWFE::BlockParticipant

Includes:

LocalParticipant

Defined in:

lib/openwfe/participants/participants.rb

Overview

This participant is used by the register_participant() method of Engine class.

engine.register_participant("the_boss") do |workitem|
    puts "the boss received a workitem"
end

After the block executes, the BlockParticipant immediately replies to the engine.

You can pass a block with two arguments : flow_expression and workitem to BlockParticipant, it will automatically adapt.

engine.register_participant("the_boss") do |fexp, wi|
    puts "the boss received a workitem from exp #{fexp.fei.to_s}"
end

Having the FlowExpression instance at hand allows for advanced tricks, beware…

It’s also OK to register a block participant without params :

engine.register_participant :alice do
    puts "Alice received a workitem"
end

Instance Attribute Summary

Attributes included from Contextual

#application_context

Instance Method Summary

• #consume(workitem) ⇒ Object
• #initialize(block0 = nil, &block1) ⇒ BlockParticipant constructor

  A new instance of BlockParticipant.

Methods included from LocalParticipant

#call_block, #get_flow_expression, #reply_to_engine

Methods included from Contextual

#get_work_directory, #init_service, #lookup

Methods included from Logging

#ldebug, #ldebug_callstack, #lerror, #lfatal, #linfo, #llog, #lunknown, #lwarn

Methods included from OwfeServiceLocator

#get_engine, #get_error_journal, #get_expool, #get_expression_map, #get_expression_pool, #get_expression_storage, #get_expression_storages, #get_journal, #get_participant_map, #get_scheduler, #get_wfid_generator

Constructor Details

#initialize(block0 = nil, &block1) ⇒ BlockParticipant

Returns a new instance of BlockParticipant.

# File 'lib/openwfe/participants/participants.rb', line 159

def initialize (block0=nil, &block1)
    @block = if block1
        block1
    else
        block0
    end
    raise "Missing a block parameter" \
        unless @block
end

Instance Method Details

#consume(workitem) ⇒ Object

# File 'lib/openwfe/participants/participants.rb', line 169

def consume (workitem)

    result = call_block @block, workitem

    workitem.set_result(result) \
        if result and result != workitem

    reply_to_engine(workitem) \
        if workitem.kind_of? InFlowWorkItem
    # else it's a cancel ite
end