Hi there, I'm unclear about some aspects of ZClasses. Imagine I have a ZClass 'A'. Instances of this ZClass have a 'messages' tab where various messages this ZClass can emit can be edited. It should look something like this: ________ ------|messages|------- Foobar reached 10 kelvin: --------------------- | Your Foobar is too| | cold, please heat | | it! | --------------------- Hyperdrive coils unwinded -------------------- | Wind up your | | hyperdrive coils!| -------------------- Where the boxes are textareas. The person who uses ZClass A can edit the particular messages that will be emitted for that instance. Now, I'm thinking about a class hierarchy where there's a ZClass B that inherits from A. ZClass B has the same messages as A, but may add a few. The 'messages' tab should automagically adapt to include the new messages. I'm having trouble finding the best way to implement this using ZClasses. One option is to use propertysheets. I may include a propertysheet 'Messages' in ZClass A. However, there is no easy way to get to that propertysheet in ZClass B. I may do it programmatically with DTML (add a property dynamically upon construction of a B instance), however, but it's far from ideal. Another problem with propertysheets is that there isn't a way to have object properties. My messages have already too many attributes, two; a title and the messsage contents. Properties have only an id and contents. Imagine I also want to add a 'criticality level' or whatever to my messages. I run into trouble with properties. Another idea I had was to make a special ZClass called 'message'. This message ZClass would have a property sheet with the title of the message, and the message itself, and criticality level if necessary, etc. The idea is then to add an instance of such a Message ZClass to my own ZClasses whenever I needed to add a message. ZClass A would implement a message tab that would automatically list all Message objects as textareas for editing (as described before). If ZClass B adds a Message, that message automatically show up in the tab. Apart from the fact that with the latest beta I still can't seem to add ZClass instances to ZClasses (I saw a report in the collector on this already), I wonder if this will work at all. Would the contained 'message' ZClass's properties be class attributes or instance attributes of ZClass A? That is, if I changed the 'Foobar too hot' message for one instance of ZClass A, would it change for all instances? That is not what I want. Some Zope Zen is still needed here to grok ZClasses fully. Am I trying to push them too far? Should I go for Python, and derive my ZClasses from a Python class? I would lose the easy way to add configurable messages (and other configurable stuff) to ZClasses that I had in mind, but in Python this isn't too hard. Responses to these musings and questions are very welcome. Regards, Martijn