Class: OpenWFE::RestoreWorkItemExpression

Inherits:

FlowExpression

• Object
• ObjectWithMeta
• FlowExpression
• OpenWFE::RestoreWorkItemExpression

Includes:

MergeMixin, ValueMixin

Defined in:

lib/openwfe/expressions/fe_save.rb

Overview

“restore” is often used in conjunction with “save” (SaveWorkItemExpression).

It can restore a workitem saved to a variable (it will actually restore the payload of that workitem) or transfer the content of a field as top attribute field.

restore :from_variable => "freezed_workitem"
    #
    # takes the freezed payload at 'freezed_workitem' and makes it
    # the payload of the current workitem

restore :from_field => "some_data"
    #
    # replaces the payload of the current workitem with the hash
    # found in the field "some_data"

restore :from_variable => "v", :to_field => "f"
    #
    # will copy the payload saved under variable "v" as the value
    # of the field "f"

restore :from_variable => "v", :merge_lead => :current
    #
    # will restore the payload of the workitem saved under v
    # but if fields of v are already present in the current workitem
    # the current values will be kept

restore :from_variable => "v", :merge_lead => :restored
    #
    # will restore the payload of the workitem saved under v
    # but the workitem v payload will have priority.

Beware : you should not restore from a field that is not a hash. The top level attributes (payload) of a workitem should always be a hash.

Since OpenWFEru 0.9.17, the ‘set-fields’ alias can be used for restore.

sequence do
    set_fields :value => { 
        "customer" => { "name" => "Zigue", "age" => 34 },
        "approved" => false }
    _print "${f:customer.name} (${f:customer.age}) ${f:approved}"
end

Along with this new alias, the expression now behave much like the ‘set’ expression, but still, targets the whole workitem payload.

Note that “set-fields” can be used outside of the body of a process definition (along with “set”) to separate ‘data preparation’ from actual process definition.

class Test44b6 < ProcessDefinition
    set_fields :value => { 
        "customer" => { "name" => "Zigue", "age" => 34 },
        "approved" => false }
    sequence do
        _print "${f:customer.name} (${f:customer.age}) ${f:approved}"
    end
end

Using set_fields at the beginning of a process can be useful for setting up forms (keys without values for now).

set_fields :value => {
    "name" => "",
    "address" => "",
    "email" => ""
}

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

• #reply(workitem) ⇒ Object

Methods included from ValueMixin

#apply, #lookup_field_attribute, #lookup_variable_attribute

Methods included from MergeMixin

#merge_workitems

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

# File 'lib/openwfe/expressions/fe_save.rb', line 175

def reply (workitem)

    from_field = lookup_string_attribute :from_field, workitem
    from_variable = lookup_string_attribute :from_variable, workitem

    merge_lead = lookup_sym_attribute :merge_lead, workitem

    merge_lead = nil \
        unless [ nil, :current, :restored ].include?(merge_lead)

    value = workitem.attributes[FIELD_RESULT]

    source = if from_field

        att = workitem.lookup_attribute from_field

        lwarn {
            "apply() field '#{from_field}' is NOT a hash, " +
            "restored anyway"
        } unless att.kind_of?(Hash)

        att

    elsif from_variable

        lookup_variable from_variable

    elsif value

        value

    else

        nil
    end

    if source

        workitem = if merge_lead
            do_merge merge_lead, workitem, source
        else
            do_overwrite workitem, source
        end
    end
    # else, don't restore anything

    reply_to_parent workitem
end