Johan Carlsson wrote:
Hi, I am trying to figure out ZPatterns and because I rather work with Python Products when with Zclasses I am trying to convert the EmployZ product to Python. So far I got half the way there, the Rack recognizes the DataSkin And on newItem in the Specialist it a new slot gets created and I can see them and their ID.
Now the problem is creating a Propertysheet in the DataSkin that gets stored in the Rack.
The attributes of a Persistent DataSkin will get stored in the Rack without too much extra work.
class EmployX( DataSkin, #VirtualSheets, ):
You need to derive EmployX from DataSkin and some Zope persistent class such as SimpleItem. Otherwise, it won't be persistent.
Accualy I don´t have to do that. Have a look at Itamar Shtull-Traurings and Heiko Stoermers FlatDatabase:
def manage_change(self, REQUEST, RESPONSE): """ Change properties """ for prop in self.database_properties.propertyMap(): name=prop['id'] if REQUEST.has_key(name): if 'w' in prop.get('mode', 'wd'): value=REQUEST.get(name) setattr(self, name, value) <<<< RESPONSE.redirect(REQUEST.URL1)
But as I noticed the "properties" was saved as attributes not as properties in a propertysheet.
That's another way of doing it. It is a bit less transparent. I find it more straightforward to make my classes SimpleItems and PropertyManagers, as it means I can just call manage_changeProperties() without writing extra methods.
I can live with that, but I still would like to know if and how to use propertysheets provided by a DataManager inside a Pyhton DataSkin?
There are two kinds of PropertySheet in Zope: DAV propertysheets Propertysheets that go with ZClasses There are also Properties for objects that are PropertyManagers, such as DTML Documents. There is an important difference in how these different types of properties work: DAV Propertysheets are independent Persistent objects Propertysheets that go with ZClasses and also PropertyManager propertysheets are stored as attributes in the objects they belong to. Therefore, in ZPatterns, you use AttributeProviders to do stuff with PropertyManager properties and ZClass-style propertysheets. You use SheetProviders to do stuff with DAV Propertysheets. If you're using ZClass-style propertysheets, you need to use DataSkin Attribute Propertysheets, rather than the default Common Instance Propertysheets. In your case, I suggest making your class Persistent, and using PropertyManager properties. The reason to use ZClass-style propertysheets is if you want to easily partition your properties into sets of properties with different permissions. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net