You have two bad assumptions here. They're unrelated except for the fact that code written with either assumption will exhibit the problem you noted. The first is that you cannot use a class attribute to do this because class attributes are not persistent. You need to make categoryList an instance attribute (instead of a class attribute). The second is that ZODB cannot detect the mutation of basic types and thus the transaction that results from a web request that calls manage_addCategory won't notice that anything has changed. You need to give it a clue by manually signifying that the instance has changed. I imagine that DefaultDublinCoreImpl already has an __init__ method (this is the usual place to initialize instance attributes), so I won't put an __init__ method in my amende example below. Instead, we'll set one dynamically based on the value of the class attribute. We'll also set a magic attribute (_p_changed) on the instance to tell ZODB that something has changed as a result of the method call. For more info on how to use persistence, see http://www.zope.org/Documentation/ZDG/Persistence.stx For more info on class attributes vs. instance attributes, a good reference is the book "Learning Python" (O'Reilly). class Store(Folder.Folder, PortalContent, DefaultDublinCoreImpl): """ Store Class """ meta_type = 'Store' _isDiscussable = 1 icon = PortalContent.icon categoryList = None def manage_addCategory(self, id, title, REQUEST = None): if self.categoryList is None: self.categoryList = [] self.categoryList.append(id) self._p_changed = 1 On Wed, 2002-05-29 at 21:35, Jeff Ross wrote:
I'm writing a product that needs a list of items inside it, e.g ['abc', '456', '243'].
The list stays intact if the server is up. But if I shutdown and restart, the list is cleared again.
Here's some of my code:
class Store(Folder.Folder, PortalContent, DefaultDublinCoreImpl): """ Store Class """
meta_type = 'Store' _isDiscussable = 1 icon = PortalContent.icon categoryList = []
def manage_addCategory(self, id, title, REQUEST = None): self.categoryList.append(id)
Is this the reason my list is getting reset to empty on restart? I don't understand. If I have a text attribute and set it to empty in the class code, then it's fine. I get my saved attribute. But my list is blown away.
Jeff
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