Patrick Stinson writes:
sorry for asking something this specific, but hidden attributes? I'm not trying to do anythin special here, it's simple inheritance. A super class has an attribute, I want to access it via one of its subclasses. Could you find it in your hear to give me a quick code example? When the derived class redefines an attribute ("site_url" in your case) of the inherited class, this definition hides the inherited one.
But maybe, that is not your problem. When you want to access an (unhidden) attribute of the inherited class, you do it in the same way as for the own attributes: classInstance.attribute By the way, Zope implements properties as attributes. Thus, normal attriute access gives you (read only) access to properties. When you want to change a property, you must use either the PropertyManager (for standard properties, such as "title") or the PropertySheet (for properties in a property sheet) API. This is either: classInstance.manage_change/editProperties(...) (PropertyManager API) or classInstance.propertysheets.sheetName.manage_change/editProperties(...) (PropertySheet API) Note that you cannot (easily) change inherited properties when the property sheet (the property is defined in) has the same name in the inherited and derived classes (avoid identical names!). Dieter PS: Please stay on the list.
yes, I noticed that property sheets with identical names in super and sub classes is bad. It does help to know that instance.property is read-only. re-implementing attriubutes? I don't even think that's possible! Thanks for the help with the PropertyManager/Sheet tip. I don't think I ever would have found that elsewhere. -P -----Original Message----- From: zope-admin@zope.org [mailto:zope-admin@zope.org]On Behalf Of Dieter Maurer Sent: Saturday, December 07, 2002 8:00 PM To: Patrick Stinson Cc: zope@zope.org Subject: RE: [Zope] ZClass inheritancs:propertysheets Patrick Stinson writes:
sorry for asking something this specific, but hidden attributes? I'm not trying to do anythin special here, it's simple inheritance. A super class has an attribute, I want to access it via one of its subclasses. Could you find it in your hear to give me a quick code example? When the derived class redefines an attribute ("site_url" in your case) of the inherited class, this definition hides the inherited one.
But maybe, that is not your problem. When you want to access an (unhidden) attribute of the inherited class, you do it in the same way as for the own attributes: classInstance.attribute By the way, Zope implements properties as attributes. Thus, normal attriute access gives you (read only) access to properties. When you want to change a property, you must use either the PropertyManager (for standard properties, such as "title") or the PropertySheet (for properties in a property sheet) API. This is either: classInstance.manage_change/editProperties(...) (PropertyManager API) or classInstance.propertysheets.sheetName.manage_change/editProperties(...) (PropertySheet API) Note that you cannot (easily) change inherited properties when the property sheet (the property is defined in) has the same name in the inherited and derived classes (avoid identical names!). Dieter PS: Please stay on the list. _______________________________________________ Zope maillist - Zope@zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )
participants (2)
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Dieter Maurer -
Patrick Stinson