From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 30 Mar 2010 14:39:36 +0000 (-0400)
Subject: - the compiler extension now allows @compiles decorators
X-Git-Tag: rel_0_6_0~82^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=43b9f0d116580474ac56c532a1427a4cdeb3748b;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- the compiler extension now allows @compiles decorators
on base classes that extend to child classes, @compiles
decorators on child classes that aren't broken by a
@compiles decorator on the base class.
---

diff --git a/CHANGES b/CHANGES
index dd6211fc1d..cca3298f07 100644
--- a/CHANGES
+++ b/CHANGES
@@ -26,7 +26,13 @@ CHANGES
     will expunge the object if the cascade also includes
     "delete-orphan", or will simply detach it otherwise.
     [ticket:1754]
-    
+
+- ext
+   - the compiler extension now allows @compiles decorators
+     on base classes that extend to child classes, @compiles
+     decorators on child classes that aren't broken by a 
+     @compiles decorator on the base class.
+   
 0.6beta3
 ========
 
diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py
index 3226b0efd8..dde49e232e 100644
--- a/lib/sqlalchemy/ext/compiler.py
+++ b/lib/sqlalchemy/ext/compiler.py
@@ -165,7 +165,7 @@ A big part of using the compiler extension is subclassing SQLAlchemy expression
 
 def compiles(class_, *specs):
     def decorate(fn):
-        existing = getattr(class_, '_compiler_dispatcher', None)
+        existing = class_.__dict__.get('_compiler_dispatcher', None)
         if not existing:
             existing = _dispatcher()
 
diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py
index 4a54375f8b..799486c02f 100644
--- a/lib/sqlalchemy/sql/visitors.py
+++ b/lib/sqlalchemy/sql/visitors.py
@@ -40,16 +40,17 @@ class VisitableType(type):
         
         # set up an optimized visit dispatch function
         # for use by the compiler
-        visit_name = cls.__visit_name__
-        if isinstance(visit_name, str):
-            getter = operator.attrgetter("visit_%s" % visit_name)
-            def _compiler_dispatch(self, visitor, **kw):
-                return getter(visitor)(self, **kw)
-        else:
-            def _compiler_dispatch(self, visitor, **kw):
-                return getattr(visitor, 'visit_%s' % self.__visit_name__)(self, **kw)
-    
-        cls._compiler_dispatch = _compiler_dispatch
+        if '__visit_name__' in cls.__dict__:
+            visit_name = cls.__visit_name__
+            if isinstance(visit_name, str):
+                getter = operator.attrgetter("visit_%s" % visit_name)
+                def _compiler_dispatch(self, visitor, **kw):
+                    return getter(visitor)(self, **kw)
+            else:
+                def _compiler_dispatch(self, visitor, **kw):
+                    return getattr(visitor, 'visit_%s' % self.__visit_name__)(self, **kw)
+
+            cls._compiler_dispatch = _compiler_dispatch
         
         super(VisitableType, cls).__init__(clsname, bases, clsdict)
 
diff --git a/test/ext/test_compiler.py b/test/ext/test_compiler.py
index d625ae0ca0..2d33b382af 100644
--- a/test/ext/test_compiler.py
+++ b/test/ext/test_compiler.py
@@ -176,6 +176,61 @@ class UserDefinedTest(TestBase, AssertsCompiledSQL):
             "timezone('utc', current_timestamp)",
             dialect=postgresql.dialect()
         )
-            
+    
+    def test_subclasses_one(self):
+        class Base(FunctionElement):
+            name = 'base'
+        
+        class Sub1(Base):
+            name = 'sub1'
+
+        class Sub2(Base):
+            name = 'sub2'
+        
+        @compiles(Base)
+        def visit_base(element, compiler, **kw):
+            return element.name
+
+        @compiles(Sub1)
+        def visit_base(element, compiler, **kw):
+            return "FOO" + element.name
+
+        self.assert_compile(
+            select([Sub1(), Sub2()]),
+            'SELECT FOOsub1, sub2',
+            use_default_dialect=True
+        )
+    
+    def test_subclasses_two(self):
+        class Base(FunctionElement):
+            name = 'base'
         
+        class Sub1(Base):
+            name = 'sub1'
+
+        @compiles(Base)
+        def visit_base(element, compiler, **kw):
+            return element.name
+
+        class Sub2(Base):
+            name = 'sub2'
+        
+        class SubSub1(Sub1):
+            name = 'subsub1'
+            
+        self.assert_compile(
+            select([Sub1(), Sub2(), SubSub1()]),
+            'SELECT sub1, sub2, subsub1',
+            use_default_dialect=True
+        )
+
+        @compiles(Sub1)
+        def visit_base(element, compiler, **kw):
+            return "FOO" + element.name
+
+        self.assert_compile(
+            select([Sub1(), Sub2(), SubSub1()]),
+            'SELECT FOOsub1, sub2, FOOsubsub1',
+            use_default_dialect=True
+        )
         
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