Re: [Sqlalchemy-tickets] [sqlalchemy] #1913: Some docs on what's "fair game" in extensions would be good

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

#1913: Some docs on what's "fair game" in extensions would be good
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 Reporter:  chrisw         |          Owner:  zzzeek                  
     Type:  enhancement    |         Status:  new                     
 Priority:  medium         |      Milestone:                          
Component:  documentation  |       Severity:  no triage selected yet  
 Keywords:                 |   Status_field:  needs questions answered
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Changes (by zzzeek):

  * type:  defect => enhancement
  * status_field:  awaiting triage => needs questions answered


Comment:

 there is a clue for sure:

 http://www.sqlalchemy.org/docs/orm/interfaces.html?highlight=mapperextension#sqlalchemy.orm.interfaces.MapperExtension.before_insert

 Column-based attributes can be modified within this method which will
 result in the new value being inserted. However no changes to the overall
 flush plan can be made, and manipulation of the Session will not have the
 desired effect. To manipulate the Session within an extension, use
 SessionExtension.

 we can't exactly predict various use cases like a "versioned" extension.
 There are certainly ways to do versioning in the MapperExtension, and
 efficiently too - just issue INSERT statements on the provided connection.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/1913#comment:1>
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