DataMapper NoMethodError：DateTime的未定义方法“ encode_json”

Question

I'm not sure if this is a DataMapper issue or something more Rails-specific:

NoMethodError: undefined method `encode_json' for Sun, 28 Nov 2010 00:00:00 -0500:DateTime

I have a model defined as follows:

class Match
 include DataMapper::Resource

 storage_names[:default] = 'matches'
 property :id, Serial, :field => 'matches_id', :required => true

 def self.find_matches
   repository.adapter.select <<-SQL
     select
       m.matches_id,
       m.begin_date,
       m.windows_time_zone,
       team1_id,
       team2_id,
       t1.name as team1,
       t2.name as team2,
       m.status,
       COALESCE(md.name,'') as match_day_name,
       s.name as season_name,
       r.name as round_name,
       c.name as competition_name,
       COALESCE(g.name,'') as group_name,
       COALESCE(m.use_gsm,'N') as use_gsm,
       COALESCE(m.team1_finalscore,0) as team1_score,
       COALESCE(m.team2_finalscore,0) as team2_score
     from matches m
     inner join round r on (r.round_id = m.round_id)
     inner join season s on (s.season_id = r.season_id)
     inner join competition c on (c.competition_id =
s.competition_id)
     inner join team t1 on (t1.team_id = m.team1_id)
     inner join team t2 on (t2.team_id = m.team2_id)
     left outer join match_day md on (m.match_day_id =
md.match_day_id)
     left outer join groups g on (r.round_id = g.round_id)
     where m.begin_date <= (CURDATE() + interval 1 day)
     and m.begin_date >= (CURDATE() - interval 1 day)
     order by m.begin_date desc
   SQL
 end

end

Calling Match.find_matches from the console returns an array of structs like the following:

#<struct matches_id=54235, begin_date=Sun, 28 Nov 2010 00:00:00 -0500,windows_time_zone="Morocco Standard Time", team1_id=937, team2_id=943,team1="Deportes Tolima", team2="La Equidad", status="N",match_day_name="Cuadrangular Semifinal Fecha 3",
season_name="Finalizacion 2010", round_name="Cuadrangular Semifinal",competition_name="Liga Postobon - Colombia", group_name="",use_gsm="N", team1_score=0, team2_score=0>

When I try Match.find_matches.to_json , it appears that to_json is choking on the begin_date format. Is there anything I can do to correct this? I'm using MySQL 5.1 DATETIME, which usually displays as yyyy-mm-dd hh:mm:ss (at least in the MySQL client), so something is formatting that in a way that encode_json can't digest.

Answer 1

This appears to be a bug in ActiveSupport::JSON.encode. The Struct type is not supported. I've opened a ticket and provide a workaround. https://rails.lighthouseapp.com/projects/8994/tickets/6077-activesupportjsonencode-fails-for-struct-types#ticket-6077-1