- local raw_value = field_tag:get_child_text("value");
- local value = boolean_values[raw_value ~= nil and raw_value];
- if value ~= nil then
- return value;
- elseif raw_value then
- return nil, "Invalid boolean representation";
- elseif required then
- return nil, "Required value missing";
+ local raw_value, err = simple_text(field_tag, required);
+ if not raw_value then return raw_value, err; end
+ local value = boolean_values[raw_value];
+ if value == nil then
+ return nil, "Invalid boolean representation:" .. raw_value;