diff options
Diffstat (limited to 'lib/sqlalchemy/ext/compiler.py')
| -rw-r--r-- | lib/sqlalchemy/ext/compiler.py | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py index 86156be1f..5ef4e1d2a 100644 --- a/lib/sqlalchemy/ext/compiler.py +++ b/lib/sqlalchemy/ext/compiler.py @@ -410,13 +410,25 @@ def compiles(class_, *specs): given :class:`.ClauseElement` type.""" def decorate(fn): + # get an existing @compiles handler existing = class_.__dict__.get('_compiler_dispatcher', None) - existing_dispatch = class_.__dict__.get('_compiler_dispatch') + + # get the original handler. All ClauseElement classes have one + # of these, but some TypeEngine classes will not. + existing_dispatch = getattr(class_, '_compiler_dispatch', None) + if not existing: existing = _dispatcher() if existing_dispatch: - existing.specs['default'] = existing_dispatch + def _wrap_existing_dispatch(element, compiler, **kw): + try: + return existing_dispatch(element, compiler, **kw) + except exc.UnsupportedCompilationError: + raise exc.CompileError( + "%s construct has no default " + "compilation handler." % type(element)) + existing.specs['default'] = _wrap_existing_dispatch # TODO: why is the lambda needed ? setattr(class_, '_compiler_dispatch', @@ -458,4 +470,5 @@ class _dispatcher(object): raise exc.CompileError( "%s construct has no default " "compilation handler." % type(element)) + return fn(element, compiler, **kw) |