Re: [Sqlalchemy-tickets] [sqlalchemy] #2875: attempt to improve the system by which engine_from_config locates keys w/ special values

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

#2875: attempt to improve the system by which engine_from_config locates keys w/
special values
------------------------------+----------------------------------
      Reporter:  zzzeek       |      Owner:  zzzeek
          Type:  enhancement  |     Status:  new
      Priority:  high         |  Milestone:  0.9.0
     Component:  engine       |   Severity:  minor - half an hour
    Resolution:               |   Keywords:
Progress State:  in queue     |
------------------------------+----------------------------------

Comment (by zzzeek):

 add it to the default strategy once we have the dialect class:

 {{{
 #!diff
 diff --git a/lib/sqlalchemy/engine/__init__.py
 b/lib/sqlalchemy/engine/__init__.py
 index 16d2141..128c4e8 100644
 --- a/lib/sqlalchemy/engine/__init__.py
 +++ b/lib/sqlalchemy/engine/__init__.py
 @@ -348,10 +348,13 @@ def engine_from_config(configuration,
 prefix='sqlalchemy.', **kwargs):
      arguments.
      """

 -    opts = util._coerce_config(configuration, prefix)
 -    opts.update(kwargs)
 -    url = opts.pop('url')
 -    return create_engine(url, **opts)
 +    options = dict((key[len(prefix):], configuration[key])
 +                   for key in configuration
 +                   if key.startswith(prefix))
 +    options['_coerce_config'] = True
 +    options.update(kwargs)
 +    url = options.pop('url')
 +    return create_engine(url, **options)


  __all__ = (
 diff --git a/lib/sqlalchemy/engine/default.py
 b/lib/sqlalchemy/engine/default.py
 index 8fb7c3b..007a3ab 100644
 --- a/lib/sqlalchemy/engine/default.py
 +++ b/lib/sqlalchemy/engine/default.py
 @@ -59,6 +59,18 @@ class DefaultDialect(interfaces.Dialect):

      supports_simple_order_by_label = True

 +    engine_config_types = dict([
 +        ('convert_unicode', util.bool_or_str('force')),
 +        ('pool_timeout', int),
 +        ('echo', util.bool_or_str('debug')),
 +        ('echo_pool', util.bool_or_str('debug')),
 +        ('pool_recycle', int),
 +        ('pool_size', int),
 +        ('max_overflow', int),
 +        ('pool_threadlocal', bool),
 +        ('use_native_unicode', bool),
 +    ])
 +
      # if the NUMERIC type
      # returns decimal.Decimal.
      # *not* the FLOAT type however.
 diff --git a/lib/sqlalchemy/engine/strategies.py
 b/lib/sqlalchemy/engine/strategies.py
 index ab9d370..aea2fc3 100644
 --- a/lib/sqlalchemy/engine/strategies.py
 +++ b/lib/sqlalchemy/engine/strategies.py
 @@ -49,11 +49,16 @@ class DefaultEngineStrategy(EngineStrategy):

          dialect_cls = u.get_dialect()

 +        coerce_config = kwargs.pop('_coerce_config', False)
 +
          dialect_args = {}
          # consume dialect arguments from kwargs
          for k in util.get_cls_kwargs(dialect_cls):
              if k in kwargs:
 -                dialect_args[k] = kwargs.pop(k)
 +                value = kwargs.pop(k)
 +                if coerce_config and k in
 dialect_cls.engine_config_types:
 +                    value = dialect_cls.engine_config_types[k](value)
 +                dialect_args[k] = value

          dbapi = kwargs.pop('module', None)
          if dbapi is None:
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2875#comment:1>
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