[Sqlalchemy-tickets] [sqlalchemy] #2596: type level events for bind/result processors

[sqlalchemy <mi...@zz...>]

#2596: type level events for bind/result processors
-------------------------+------------------------------------
 Reporter:  zzzeek       |           Owner:  zzzeek
     Type:  enhancement  |          Status:  new
 Priority:  medium       |       Milestone:  0.8.xx
Component:  sql          |        Severity:  major - 1-3 hours
 Keywords:               |  Progress State:  not decided upon
-------------------------+------------------------------------
 this would allow easy addition of bind and result handlers across existing
 types without the need for using custom types.

 {{{
 #!diff
 diff -r d576b5fd0cb9 lib/sqlalchemy/types.py
 --- a/lib/sqlalchemy/types.py   Thu Oct 25 12:07:38 2012 -0400
 +++ b/lib/sqlalchemy/types.py   Thu Oct 25 12:14:41 2012 -0400
 @@ -273,7 +273,14 @@
              return dialect._type_memos[self]['bind']
          except KeyError:
              d = self._dialect_info(dialect)
 -            d['bind'] = bp = d['impl'].bind_processor(dialect)
 +            if self.dispatch.bind_processor:
 +                bp = self.dispatch.bind_processor(self, dialect)
 +                if bp is None:
 +                    bp = d['impl'].bind_processor(dialect)
 +            else:
 +                bp = d['impl'].bind_processor(dialect)
 +
 +            d['bind'] = bp
              return bp

      def _cached_result_processor(self, dialect, coltype):
 @@ -283,10 +290,18 @@
              return dialect._type_memos[self][coltype]
          except KeyError:
              d = self._dialect_info(dialect)
 +
 +            if self.dispatch.result_processor:
 +                rp = self.dispatch.result_processor(self, dialect,
 coltype)
 +                if rp is None:
 +                    rp = d['impl'].result_processor(dialect, coltype)
 +            else:
 +                rp = d['impl'].result_processor(dialect, coltype)
 +
              # key assumption: DBAPI type codes are
              # constants.  Else this dictionary would
              # grow unbounded.
 -            d[coltype] = rp = d['impl'].result_processor(dialect,
 coltype)
 +            d[coltype] = rp
              return rp

      def _dialect_info(self, dialect):
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2596>
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