Re: [Sqlalchemy-tickets] [sqlalchemy] #2808: AssociationProxy should use keywords on create

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

#2808: AssociationProxy should use keywords on create
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      Reporter:  schlamar                  |      Owner:  zzzeek
          Type:  enhancement               |     Status:  new
      Priority:  medium                    |  Milestone:  0.8.xx
     Component:  ext                       |   Severity:  minor - half an
    Resolution:                            |  hour
Progress State:  needs questions answered  |   Keywords:
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Comment (by zzzeek):

 that's what "creator" is for:

 {{{
 #!python
 class User(Base):
     __tablename__ = 'user'
     id = Column(Integer, primary_key=True)
     name = Column(String(64))
     keywords = association_proxy('user_keywords', 'keyword',
 creator=lambda v: UserKeyword(keyword=v))
 }}}


 this can be generalized with your preferred style:

 {{{
 #!python
 def my_association_proxy(src, target):
     def create(value):
         target_cls = prox.target_class
         return target_cls(**{target: value})
     prox = association_proxy(src, target, creator=create)
     return prox

 class User(Base):
     __tablename__ = 'user'
     id = Column(Integer, primary_key=True)
     name = Column(String(64))
     keywords = my_association_proxy('user_keywords', 'keyword')
 }}}


 it should be apparent why we can't just change
 `_AssociationList._create()` here.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2808#comment:6>
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