Martijn. Actually I think I said prevalent, not relevant :-). I agree about relevance in both circumstances so highlighted container, location and traversal as key issues for refactoring legacy code. I am concerned about retaining heirarchical arrangements and being able to use existing traversal methods. I really like what you are doing here and will look at your implementation. I appreciate you for pointing this out. Many thanks. Regards, David Martijn Faassen wrote:
Hi there,
David Pratt wrote: [snip]
For me, the crux of the rdb approach for legacy code is the container, location and traversal. You have been very generous with your examples. I am really hoping for a clearer idea of handling Container, OrderedContainer, and Location which is prevalent in legacy code. Overall, I can say that I quite the innovation here in getting to a 'leaner' concept of Zope.
I myself wouldn't be inclined to call Container and Location only relevant to legacy code.
It's very convenient to have a RDB-backed object have a location, as that allows you to get the URL for it in the regular manner.
For Container, in the megrok.rdb prototype code we actually make containers be SQLAlchemy 'MappedCollection' objects. MappedCollection happens to implement the container API already. This way we can make relations be containers by writing something like:
class Departments(rdb.Container): # this is a MappedCollection rdb.key('title')
class Faculty(rdb.Model): # rdb.table_name('faculty') is the default __tablename__ = 'faculty'
grok.traversable('departments')
departments = relation('Department', backref='faculty', collection_class=Departments)
The 'departments' attribute is a container you can traverse into this way. You can hook up views to Departments just like you would to any container.
Regards,
Martijn
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