Method inferMeasureClassName

ruby/engine/RubyEngine.cpp:154–203

}

std::string RubyEngine::inferMeasureClassName(const openstudio::path& measureScriptPath) {

  auto inferClassNameCmd = fmt::format(R"ruby(
ObjectSpace.garbage_collect
ObjectSpace.garbage_collect
# Measure should be at root level (not inside a module) so we can just get constants
measurePath = '{}'
prev = Object.constants
# puts "prev = #{{prev}}"
load measurePath # need load in case have seen this script before
just_defined = Object.constants - prev
# puts "just_defined = #{{just_defined}}"
just_defined.select!{{|c| Object.const_get(c).ancestors.include?(OpenStudio::Measure::OSMeasure)}}
# puts "just_defined, filtered = #{{just_defined}}"

if just_defined.empty?
  raise "Unable to extract OpenStudio::Measure::OSMeasure object from " +
       measurePath + ". The script should contain a class that derives " +
      "from OpenStudio::Measure::OSMeasure and should close with a line stating " +
      "the class name followed by .new.registerWithApplication."
end
if just_defined.size > 1
  raise "Found more than one OSMeasure at #{{measurePath}}: #{{just_defined}}"
end
c = just_defined[0]
class_info = Object.const_get(c)
$measure_name = class_info.to_s

# Undef what we loaded
just_defined.each {{|x| Object.send(:remove_const, x) }}
ObjectSpace.garbage_collect
ObjectSpace.garbage_collect
)ruby",
                                       measureScriptPath.generic_string());

  std::string className;

  try {
    exec(inferClassNameCmd);
    ScriptObject measureClassNameObject = eval("$measure_name");
    // measureClassNameObject = rubyEngine->eval(fmt::format("{}.new()", className));
    // ScriptObject measureClassNameObject = rubyEngine->eval(inferClassName);
    className = getAs<std::string>(measureClassNameObject);
  } catch (const RubyException& e) {
    auto msg = fmt::format("Failed to infer measure name from {}: {}\nlocation={}", measureScriptPath.generic_string(), e.what(), e.location());
    fmt::print(stderr, "{}\n", msg);
  }

  return className;
}

// Ideally this would return a openstudio::measure::OSMeasure* or a shared_ptr<openstudio::measure::OSMeasure> but this poses memory management
// issue for the underlying ScriptObject (and VALUE or PyObject), so just return the ScriptObject