modeling-users

[Modeling-users] dynamic metaclass overwrites custom methods

[<no...@ti...>]

Hello,

if I define:

class A:
    __metaclass__ = dynamic.CustomObjectMeta
    entityName = 'A'
    mdl_define_properties = 1

    def setName( self, value ):
	pass

name being a class property, when the metaclass __new__ method populates
the instance with code it overrides setName with the stock one.
My fix here is to check for the existence of the method before overriding
and rename it to 'mdl_'+method_name (which might not be inline
with your naming conventions) in case it's already there.

patch follows

comments anyone?

cheers
--
Delio

diff -aur /home/delio/tmp/ModelingCore-0.9-pre-17.1/Modeling/dynamic.py ./dynamic.py
--- /home/delio/tmp/ModelingCore-0.9-pre-17.1/Modeling/dynamic.py       2004-02-17 09:01:06.000000000 +1300
+++ ./dynamic.py        2004-08-31 19:51:40.000000000 +1200
@@ -265,6 +265,9 @@
   func_name, c=getter_code(prop)
   info(classdict, "adding getter: %s"%func_name)
   getter=function_for_code(c, func_name)
+  if classdict.has_key( func_name ):
+    func_name = 'mdl_' + func_name
+    info(classdict, "getter already defined renaming to: %s"%func_name)
   classdict[func_name]=getter
 
 def define_getters(entity, classname, classdict):
@@ -277,6 +280,9 @@
   for func_name, c in names_and_funcs:
     info(classdict, "adding setter: %s"%func_name)
     setter=function_for_code(c, func_name)
+    if classdict.has_key( func_name ):
+        func_name = 'mdl_' + func_name
+        info(classdict, "setter already defined renaming to: %s"%func_name)
     classdict[func_name]=setter
 
 def define_setters(entity, classname, classdict):

Re: [Modeling-users] dynamic metaclass overwrites custom methods

[Sebastien B. <sbi...@us...>]

        Hi,

no...@ti... wrote:
> Hello,
>=20
> if I define:
>=20
> class A:
>     __metaclass__ =3D dynamic.CustomObjectMeta
>     entityName =3D 'A'
>     mdl_define_properties =3D 1
>=20
>     def setName( self, value ):
> 	pass
>=20
> name being a class property, when the metaclass __new__ method populates
> the instance with code it overrides setName with the stock one.
> My fix here is to check for the existence of the method before overriding
> and rename it to 'mdl_'+method_name (which might not be inline
> with your naming conventions) in case it's already there.
>=20
> patch follows
>=20
> comments anyone?

That should be handled, you're absolutely right.  However, I would
suggest to make a 'warning' instead, and to overwrite the already
defined method m() with a new one calling simply self.willChange()
before calling m() --and the same for getAttribute()() but w/
self.willRead() instead.

  What do you think?

-- S=E9bastien.


PS: for Ernesto: I did not forget about your post on properties, I just
    did not take the time to get back on it yet, sorry.


>=20
> cheers
> --
> Delio
>=20
> diff -aur /home/delio/tmp/ModelingCore-0.9-pre-17.1/Modeling/dynamic.py .=
/dynamic.py
> --- /home/delio/tmp/ModelingCore-0.9-pre-17.1/Modeling/dynamic.py       2=
004-02-17 09:01:06.000000000 +1300
> +++ ./dynamic.py        2004-08-31 19:51:40.000000000 +1200
> @@ -265,6 +265,9 @@
>    func_name, c=3Dgetter_code(prop)
>    info(classdict, "adding getter: %s"%func_name)
>    getter=3Dfunction_for_code(c, func_name)
> +  if classdict.has_key( func_name ):
> +    func_name =3D 'mdl_' + func_name
> +    info(classdict, "getter already defined renaming to: %s"%func_name)
>    classdict[func_name]=3Dgetter
>=20=20
>  def define_getters(entity, classname, classdict):
> @@ -277,6 +280,9 @@
>    for func_name, c in names_and_funcs:
>      info(classdict, "adding setter: %s"%func_name)
>      setter=3Dfunction_for_code(c, func_name)
> +    if classdict.has_key( func_name ):
> +        func_name =3D 'mdl_' + func_name
> +        info(classdict, "setter already defined renaming to: %s"%func_na=
me)
>      classdict[func_name]=3Dsetter
>=20=20
>  def define_setters(entity, classname, classdict):

Re: [Modeling-users] dynamic metaclass overwrites custom methods

[<no...@ti...>]

On 02 Sep 2004 20:42:44 +0200
Sebastien Bigaret <sbi...@us...> wrote:

 
> That should be handled, you're absolutely right.  However, I would
> suggest to make a 'warning' instead, and to overwrite the already
> defined method m() with a new one calling simply self.willChange()
> before calling m() --and the same for getAttribute()() but w/
> self.willRead() instead.

Letting the framework call willChange/willRead *before* calling my 
biz logic sounds elegant but takes the freedom to define if/when to call
them away, plus I like not to write code that addresses "_AttrName" internal
attributes directly and prefer to let the framework generated methods do it.
On top of that it makes code generation a little bit more complex for no
clear (? to me ?) advantage, I'd stick to the simple solution :)
what do you think?

--
Delio