RE: [Zope-dev] A product class that subclasses another product
-----Original Message----- From: Itai Tavor [mailto:itavor@vic.bigpond.net.au] Sent: Wednesday, May 19, 1999 11:10 PM To: zope-dev@zope.org Subject: [Zope-dev] A product class that subclasses another product
Hi,
I'm building several products that need to share several common attributes and methods, so I put those is a product ('Master') that the other products subclass.
My problem is that I can't figure out how to call methods in the Master class and how to access its attributes.
Very simplified, it looks something like this:
class Master:
def __init__(self, status, REQUEST=None): """Initialize a new master object""" self.status = status
def manage_edit(self, status, REQUEST=None): """Change object properties""" self.status = status
def Visible(self): """Check if object's status is 'visible'""" if self.status == 4: return 1 return 0
from Products.Master import Master class Foo(Master):
meta_type = 'Foo' id = '' icon = 'misc_/Foo/icon'
def __init__(self, id, title, status, REQUEST): """Create a new article entry""" self.id = id self.title = title Master(status, REQUEST)
def manage_edit(self, title, status, REQUEST=None): """Change information for object""" self.title = title Master.manage_edit(status, REQUEST)
The above simply fails to find the Master methods. I tried Master.Master.manage_edit, as well as doing self.master = Master(status, REQUEST) in __init__ and then master.manage_edit(...), but neither worked. Also, is it possible to access attributes of the Master class, or do I need to define methods in Master to return attributes?
Your question could best be answered on the Python mailing list, as this is a Python question (in the context of Zope). I suspect Computed attributes could help you out here in ExtensionClasses, but there may be a Python mechanism I am unaware of that can solve the problem without using Computed attributes. The Python list can be found at http://www.python.org -Michel
Thanks Itai Tavor -- Itai Tavor -- "Je sautille, donc je suis." -- itavor@vic.bigpond.net.au -- - Kermit the Frog -- -- -- -- "Every day, once a day, give yourself a present" - Dale Cooper --
_______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org http://www.zope.org/mailman/listinfo/zope-dev
(For non-developer, user-level issues, use the companion list, zope@zope.org, http://www.zope.org/mailman/listinfo/zope )
On Sun, 23 May 1999, Michel Pelletier wrote:
-----Original Message----- From: Itai Tavor [mailto:itavor@vic.bigpond.net.au] Sent: Wednesday, May 19, 1999 11:10 PM To: zope-dev@zope.org Subject: [Zope-dev] A product class that subclasses another product
Hi,
I'm building several products that need to share several common attributes and methods, so I put those is a product ('Master') that the other products subclass.
My problem is that I can't figure out how to call methods in the Master class and how to access its attributes.
Very simplified, it looks something like this:
class Master:
def __init__(self, status, REQUEST=None): """Initialize a new master object""" self.status = status
def manage_edit(self, status, REQUEST=None): """Change object properties""" self.status = status
def Visible(self): """Check if object's status is 'visible'""" if self.status == 4: return 1 return 0
from Products.Master import Master class Foo(Master):
meta_type = 'Foo' id = '' icon = 'misc_/Foo/icon'
def __init__(self, id, title, status, REQUEST): """Create a new article entry""" self.id = id self.title = title Master(status, REQUEST) This should be Master.__init__(status, REQUEST), otherwise you are creating and discarding a Master instance.
def manage_edit(self, title, status, REQUEST=None): """Change information for object""" self.title = title Master.manage_edit(status, REQUEST) This should work. If it doesn't, something very strange is going on. (which might be occasioned by your peculiar syntactic initialization above.)
The above simply fails to find the Master methods. I tried Master.Master.manage_edit, as well as doing self.master = Master(status, REQUEST) in __init__ and then master.manage_edit(...), but neither worked. Also, is it possible to access attributes of the Master class, or do I need to define methods in Master to return attributes? It should be possible to access attributes directly, it violates the principle of encapsulation, but what the hey... Oh, wait a minute, I think I might have it. I think you need to manually pass in 'self'!! try Master.__init__(self, status, REQUEST) and Master.manage_edit(self, status, REQUEST) I think that should do it.
What you are doing here, is not calling attributes of your base class instance, because there is no such instance. Rather, you are manually calling methods of your base CLASS (not instance), and so must pass in self, since they are 'unbound' methods. Have fun!
Your question could best be answered on the Python mailing list, as this is a Python question (in the context of Zope). I suspect Computed attributes could help you out here in ExtensionClasses, but there may be a Python mechanism I am unaware of that can solve the problem without using Computed attributes.
The Python list can be found at http://www.python.org
-Michel
Thanks Itai Tavor -- Itai Tavor -- "Je sautille, donc je suis." -- itavor@vic.bigpond.net.au -- - Kermit the Frog -- -- -- -- "Every day, once a day, give yourself a present" - Dale Cooper --
_______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org http://www.zope.org/mailman/listinfo/zope-dev
(For non-developer, user-level issues, use the companion list, zope@zope.org, http://www.zope.org/mailman/listinfo/zope )
_______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org http://www.zope.org/mailman/listinfo/zope-dev
(For non-developer, user-level issues, use the companion list, zope@zope.org, http://www.zope.org/mailman/listinfo/zope ) -- Howard Clinton Shaw III - Grum St. Thomas High School #include "disclaimer.h"
participants (2)
-
Howard Clinton Shaw III -
Michel Pelletier