The server has implemented an Extended Runner class which automates the process of persisting measures and their argument values across a datapoint. The class is implemented here. The following command inside the run method class of a measure returns a hash of previous measures and their arguments:

runner.former_workflow_arguments

An example of this hash, saved as a json, is as follows:

{ "set_dr_weather_file":{"weather_directory_name":"weather","weather_file_name":"USA_CO_Denver.Intl.AP.725650_TMY3.epw"}, "idf_reference_building_selector":{"building_type":"Stand-aloneRetailNew2004"}, "set_timestep":{"timestep":"60"}, "hardsize_dx_coil":{"cfm_per_ton":"370","square_foot_per_ton":"350"} }

This functionality is currently in the EnergyPlus-8.3.0 develop branch of the Workflow Gem, and has not yet been released on rubygems. To use it ensure your Gemfile has the following line in it:

gem "openstudio-workflow", :github => "NREL/OpenStudio-workflow-gem", :branch => 'EnergyPlus-8.3.0'
'develop'

Finally, run bundle update and bundle install from the command line to set your openstudio-workflow opentstudio-workflow gem to the E+ 8.3.0 development branch of github.