- [feature] Added a hook to the system of rendering

CREATE TABLE that provides access to the render for each
Column individually, by constructing a @compiles
function against the new schema.CreateColumn
construct.  [ticket:2463]

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py
index d5fbec518..e3e668364 100644
--- a/lib/sqlalchemy/ext/compiler.py
+++ b/lib/sqlalchemy/ext/compiler.py
@@ -368,8 +368,12 @@ Example usage::
 
 """
 from .. import exc
+from ..sql import visitors
 
 def compiles(class_, *specs):
+    """Register a function as a compiler for a
+    given :class:`.ClauseElement` type."""
+
     def decorate(fn):
         existing = class_.__dict__.get('_compiler_dispatcher', None)
         existing_dispatch = class_.__dict__.get('_compiler_dispatch')
@@ -392,6 +396,17 @@ def compiles(class_, *specs):
         return fn
     return decorate
 
+def deregister(class_):
+    """Remove all custom compilers associated with a given
+    :class:`.ClauseElement` type."""
+
+    if hasattr(class_, '_compiler_dispatcher'):
+        # regenerate default _compiler_dispatch
+        visitors._generate_dispatch(class_)
+        # remove custom directive
+        del class_._compiler_dispatcher
+
+
 class _dispatcher(object):
     def __init__(self):
         self.specs = {}