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Subject: RE: Best Practices Question
Date: Tue, 5 May 2009 10:33:51 +1200
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Thread-Topic: Best Practices Question
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From: "Weddle, Anthony" <Anthony.Weddle@bluescopesteel.com>
To: <user@cayenne.apache.org>

Wouldn't it be better to use a nested context for "edit mode"? Once
committed, those changes would be visible in the shared context.

Tony

-----Original Message-----
From: Aristedes Maniatis [mailto:ari@ish.com.au]=20
Sent: Wednesday, 22 April 2009 12:32 p.m.
To: user@cayenne.apache.org
Subject: Re: Best Practices Question


On 22/04/2009, at 6:40 AM, Ylan Segal wrote:

> In a web app where each session has a DataContext, do I need to =20
> worry about data caching in different DataContexts?

I'd like to add just one further point. It is a common design pattern =20
to create one read-only 'shared' context which is used to fetch and =20
display information. This shared context lives for the life of the =20
application. Then when users 'go into edit mode' whatever that means =20
for your application, you create a new context for them and manage =20
their changes until they save in that dedicated context.

You need to be careful because you cannot relate two objects in =20
different contexts, but it isn't hard to copy objects from one context =20
to another.

There is nothing in Cayenne which enforces a context read-only or =20
'shared', it is just the manner in which you use it.

Regards
Ari