code: def search_by_subject(match_str, exclude_str = nil)
        items do |obj|
          match = {:contains => {
            :containment_mode => 'Substring',
            :containment_comparison => 'IgnoreCase',
            :field_uRI => {:field_uRI=>'item:Subject'},
            :constant => {:value =>match_str}
          }}
          unless exclude_str.nil?
            excl = {:not =>
              {:contains => {
                :containment_mode => 'Substring',
                :containment_comparison => 'IgnoreCase',
                :field_uRI => {:field_uRI=>'item:Subject'},
                :constant => {:value =>exclude_str}
              }}
            }
  
            match[:and] = [{:contains => match.delete(:contains)}, excl]
          end
          obj.restriction = match
        end
      end
docs: Search on the item subject
   @param [String] match_str A simple string paramater to match against the
     subject.  The search ignores case and does not accept regexes... only strings.
   @param [String,nil] exclude_str A string to exclude from matches against
     the subject.  This is optional.