Consider the case where we have two (or more) properties that appear in a number of classes, such as a Point class:
class Point(db.Model): x = db.IntegerProperty() y = db.IntegerProperty() I want a Circle class to have the members "center" and "radius," which is a point and an integer; Square to have the members "topleft" and "width", which is a point and an integer; Rectangle to have "topleft" and "bottomright" which is two points; and so forth. How should this family of classes be implemented? It would be possible to use ReferenceProperty, for example ... class Circle(db.Model): center = db.ReferenceProperty(Point) radius = db.IntegerProperty() ... but I imagine there would be severe performance consequences. It would also be possible to use inheritance , for example ... class Circle(Point): radius = db.IntegerProperty() ... but that woud confuse IsA and HasA relationships and be a mess for classes with more than one Point. With the ReferenceProperty implementation in the current API, Circle.get() fetches the Point data, but Circle.put() [in my tests] does not update the Point data. If the Point data in a Circle object is changed, I must [in my tests] invoke Point.put(). Is there another way? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
