[ZDP] BackTalk to Document The Zope Book (2.5 Edition)/Extending Zope
Sat, 31 Aug 2002 02:44:28 -0400
A comment to the paragraph below was recently added via http://www.zope.org/Documentation/Books/ZopeBook/current/CustomZopeObjects.stx#3-44
As you can see, this sheet looks very much like the *Properties* view
on Zope objects. Here, you can create new properties on this sheet.
Properties on Property Sheets are exactly like Properties on Zope
objects, they have a name, a type, and a value.
% Anonymous User - Aug. 31, 2002 2:44 am:
If I create a "selection" property, then what is the context in which it searches for the method? Is the
context any different between the master class and the instances? Should it be?
An example of my problem follows. Create a new ZClass object called "Parrot" in a convenient product folder.
Create a method on "Parrot" called "status_list". I suggest a simple Python script will do, such as one that
immediately returns a list of strings (like return ["passed on", "ceased to be", ...] etc). Now create a new
common instance property sheet for the class, called "properties". In this property sheet, add a property
named "status" with a type of "selection" and a value of "status_list". Note that the value appears as "no
value for status_list" when added. Now create an instance of "Parrot" somewhere and inspect its properties.
Note that the select list is populated with the list of strings returned by the "status_list" method.
It seems reasonable to me that you'd want these two cases to behave identically, not differently. In what
part of the product folder should such a method/script be placed such that it is equally accessible to the
class property sheets and the instance property sheets?