I also find it's really important when using Hibernate. Hibernate is a total 
dog unless all your fetches are Lazy (so you only load what you need). With any 
UI, you load your entity and display a certain amount, but based on user 
action, you might need lazy loaded dependencies - with a loadable detachable 
model, the main entity is always 'fresh' in the session and lazily loaded 
dependencies are always available. It means everything in your data can be 
specified to be lazy loaded. Your data model is clean, your UI is clean.

In other UIs frameworks, or when I've used Wicket without LDMs, I spend half my 
time dealing with Lazy Load Exceptions, or having to pre-load certain lazy 
loaded entities for certain screens, that may or may not ever be used. You end 
up changing your data model to fit your UI (ugh!) or having tons of duplicated, 
effectively redundant, UI specific service methods (ugh!).


-----Original Message-----
From: Chris Colman []
Sent: Friday, 23 November 2012 12:53 AM
Subject: RE: How important is detaching models really ?

I guess in more complex apps the UI elements end up with lots of references to 
model objects so detaching does save a lot of memory and it also makes 
transferring session data from one web server to another (if required) in a 
multi server environment, much more efficient. I have experienced the result of 
accidentally serializing an object graph with megabytes of data that didn't use 
detach - ouch!

The other benefit of detaching is your model will expose updates to the UI (if 
a redisplay occurred) that were made in other ORM sessions (depending on your 
ORM). Keeping a non detached copy of the model object will typically be like 
caching it in it's current state for most ORMs - i.e. it can get stale

>-----Original Message-----
>From: tobi []
>Sent: Thursday, 22 November 2012 9:10 PM
>Subject: How important is detaching models really ?
>Hi guys,
> From my understanding & experiments with Wicket's built-in session
>inspector , detaching models seems to just affect the size of the page
>store (and of course cut-down the amount of I/O required for
>the object graph). The session size shown on my pages is a constantly
>low value (<1k , we're storing nothing except the currently logged-in
>So it *seems* not detaching models has no effect on the (long-term)
>memory footprint of a Wicket application.
>According to
> , not
>detaching models should affect the session size but at least looking at
>the inspector I can't see this. Is the wiki article still correct / the
>inspector not telling the truth ?
>P.S. I'm using Wicket 1.5.8 btw
>To unsubscribe, e-mail:
>For additional commands, e-mail:

To unsubscribe, e-mail:
For additional commands, e-mail:

EMAIL DISCLAIMER This email message and its attachments are confidential and 
may also contain copyright or privileged material. If you are not the intended 
recipient, you may not forward the email or disclose or use the information 
contained in it. If you have received this email message in error, please 
advise the sender immediately by replying to this email and delete the message 
and any associated attachments. Any views, opinions, conclusions, advice or 
statements expressed in this email message are those of the individual sender 
and should not be relied upon as the considered view, opinion, conclusions, 
advice or statement of this company except where the sender expressly, and with 
authority, states them to be the considered view, opinion, conclusions, advice 
or statement of this company. Every care is taken but we recommend that you 
scan any attachments for viruses.

To unsubscribe, e-mail:
For additional commands, e-mail:

Reply via email to