Class: OpenWFE::EvalExpression

Inherits:
FlowExpression show all
Includes:
ValueMixin
Defined in:
lib/openwfe/expressions/fe_misc.rb

Overview

An advanced expression : it takes the value in a field or variable (or the nested value) and evaluates it as a process definition.

sequence
    set :field => "code", :value => "<print>hello 0</print>"
    _eval :field_def => "code"
    set :field => "code", :value => "_print 'hello 1'"
    _eval :field_def => "code"
end

will print “hello0nhello1”.

This expression can be useful for evaluating process definition snippets coming from participants directly.

It’s also dangerous. This ‘eval’ expression will raise an error if the parameter :dynamic_eval_allowed in the engine’s application context is not set to true.

Instance Attribute Summary

Attributes inherited from FlowExpression

#apply_time, #attributes, #children, #environment_id, #fei, #parent_id, #raw_representation

Attributes included from Contextual

#application_context

Instance Method Summary collapse

Methods included from ValueMixin

#apply, #lookup_field_attribute, #lookup_variable_attribute

Methods inherited from FlowExpression

#apply, #cancel, #clean_children, #delete_variable, #dup_environment, #fetch_environment, #fetch_text_content, #get_binding, #get_environment, #get_parent, #get_root_environment, #has_attribute, #initialize, is_definition, is_definition?, #lookup_attribute, #lookup_attributes, #lookup_boolean_attribute, #lookup_comma_list_attribute, #lookup_downcase_attribute, #lookup_ref, #lookup_string_attribute, #lookup_sym_attribute, #lookup_value, #lookup_variable, #lookup_vf_attribute, names, #new_environment, new_exp, #owns_its_environment?, #paused?, #remove_child, #reply_to_parent, #set_variable, #store_itself, #synchronize, #to_s, #to_yaml_properties

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

Methods inherited from ObjectWithMeta

#class_def, meta_def, meta_eval, metaclass

Constructor Details

This class inherits a constructor from OpenWFE::FlowExpression

Instance Method Details

#reply(workitem) ⇒ Object 



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# File 'lib/openwfe/expressions/fe_misc.rb', line 193

def reply (workitem)

    raise "dynamic evaluation of process definitions is not allowed" \
        if @application_context[:dynamic_eval_allowed] != true

    df = lookup_vf_attribute(workitem, 'def') || workitem.get_result

    return reply_to_parent(workitem) unless df
        #
        # currently, 'nothing to eval' means, 'just go on'

    ldebug { "apply() def is >#{df}<" }

    raw_expression = build_raw_expression df

    #puts
    #puts "======================================"
    #puts raw_expression.to_s
    #puts raw_expression.raw_representation
    #puts "======================================"
    #puts

    raw_expression.apply workitem
end