Great Pete, interesting!
Can you post a little sample solution? :)
Thanks!
Matteo
On Tuesday, July 9, 2013 5:29:57 PM UTC+2, PeteA wrote:
>
> Thanks for the update - glad you've got it sorted :). Collection sync is
> always a pain…
>
>
>
> I've just started testing a custom AutoMapper IObjectMapper implementation
> which does a full model collection <-- --> entity collection sync; if
> anyone's interested in giving feedback or improvements then drop me a
> note. It's currently at a very primitive stage, but works for basic
> scenarios and allows code such as
>
>
>
> return this.WorkUnit.Execute( (session, context) => {
>
> var entity = session.Get<Entity>(model.Id);
>
> if(entity == null) context.Fail(…);
>
> return context.Map(model,
> entity); // Entire object graph gets
> synced here
>
> })
>
>
>
> /Pete
>
>
>
> *From:* [email protected] <javascript:> [mailto:
> [email protected] <javascript:>] *On Behalf Of *Matteo Migliore
> *Sent:* 09 July 2013 14:25
> *To:* [email protected] <javascript:>
> *Subject:* Re: [nhusers] Modify the collections of an entity "collection
> was modified" exception
>
>
>
> I found the issue, it was because I did the mapping from the DTO (command)
> to the entity.
>
> In a child entity there was a navigation property to the parent that came
> from the mapping (AutoMapper) instead that from the loaded entity from the
> session. So the Child.Parent instance was different from "var parent =
> Session.Load(id)" instance.
>
>
>
> This situation caused the problem. Now I copied the loaded instance in the
> child property and everything works.
>
>
>
> P.S.
>
> So the Synchronize method is correct, is possible to use it.
>
>
> Thanks!
>
> On Friday, July 5, 2013 3:34:13 PM UTC+2, Matteo Migliore wrote:
>
> Hi Pete,
>
> I completely agree, clonin is just a patch, but I placed ToArray
> everywhere and the problem persists.
>
> I also wrote a unit test and with not lazy collection everything works
> fine.
>
> I've the exception when I call Session.Merge, and the StackTrace does
> not contain nothing,
> also without "Just my code" enabled.
>
> I really cannot understand the problem and how to reproduce it in a unit
> test.
>
>
> On Fri, Jul 5, 2013 at 12:03 PM, Pete Appleton
> <[email protected] <javascript:>> wrote:
> > Cloning is definitely the wrong solution IMO, the underlying issue is
> exactly what the exception message says. My original code assumed that
> 'toRemove' was the collection that was getting modified during iteration,
> but clearly I'm wrong if it didn't work. Best suggestion for you is to
> carefully work through the exception stack trace to find out which
> collection is the problem; once you've found that, then use the ToList() /
> ToArray() technique. NB, you may find it helpful to untick the 'Just my
> code' option in the VS debugger options.
> >
> > /Pete
> >
> > -----Original Message-----
> > From: [email protected] <javascript:> on behalf of Matteo
> Migliore
> > Sent: Thu 7/4/2013 4:49 PM
> > To: [email protected] <javascript:>
> > Subject: Re: [nhusers] Modify the collections of an entity "collection
> was modified" exception
> >
> > Chris, Pete
> >
> > the ToDictionary is not deferred exactly the ToList and ToArray,
> > so for me is not needed to do anything more.
> >
> > Instead the clone of the entity works, but I don't like it, because the
> collections
> > are modified also if not necessary.
> >
> > Idea? :)
> >
> > Thanks!
> > Matteo
> >
> > On Thursday, July 4, 2013 5:11:30 PM UTC+2, PeteA wrote:
> >
> > Change
> > var toRemove = firstCollection.Where(item =>
> secondCollection.All(x => x.Key != item.Key));
> > to
> > var toRemove = firstCollection.Where(item =>
> secondCollection.All(x => x.Key != item.Key)).ToArray();
> >
> > As it stands, your code is lazily iterating toRemove; as soon as
> something's removed from it, you'll get exception you described. This is
> not related to NHibernate, it's a standard 'feature' of .NET :).
> >
> > /Pete
> >
> > -----Original Message-----
> > From: [email protected] <javascript:> on behalf of
> Matteo Migliore
> > Sent: Thu 7/4/2013 11:58 AM
> > To: [email protected] <javascript:>
> > Subject: [nhusers] Modify the collections of an entity
> "collection was modified" exception
> >
> > Hi,
> >
> > I obtain the error "Collection was modified; enumeration
> operation may not execute." when I try to save (merge)
> > a loaded entity.
> >
> > I use AutoMapper to write the values from the DTO (command) to
> the loaded entity and this method to synchronize
> > the collection between the entity and the command:
> >
> > public static ICollection<TFirst> Synchronize<TFirst, TSecond>(
> > this ICollection<TFirst> first,
> > IEnumerable<TSecond> second,
> > Func<TSecond, TFirst> convert = null,
> > Func<TFirst, int> firstHash = null,
> > Func<TSecond, int> secondHash = null)
> > {
> > if (firstHash == null)
> > {
> > firstHash = x => x.GetHashCode();
> > }
> >
> > if (secondHash == null)
> > {
> > secondHash = x => x.GetHashCode();
> > }
> >
> > if (convert == null)
> > {
> > convert = x => Mapper.Map<TFirst>(x);
> > }
> >
> > var firstCollection = first.ToDictionary(x =>
> firstHash(x), x => x);
> > var secondCollection = second.ToDictionary(x =>
> secondHash(x), x => x);
> >
> > var toAdd = secondCollection.Where(item =>
> firstCollection.All(x => x.Key != item.Key)).Select(x => convert(x.Value));
> >
> > foreach (var item in toAdd)
> > {
> > first.Add(item);
> > }
> >
> > var toRemove = firstCollection.Where(item =>
> secondCollection.All(x => x.Key != item.Key));
> >
> > foreach (var item in toRemove)
> > {
> > first.Remove(item.Value);
> > }
> >
> > return first;
> > }
> >
> > How can I fix the problem?
> >
> > Thanks,
> > Matteo
> >
> > --
> > You received this message because you are subscribed to the
> Google Groups "nhusers" group.
> > To unsubscribe from this group and stop receiving emails from
> it, send an email to [email protected] <javascript:> .
> > To post to this group, send email to
> > [email protected]<javascript:> .
> > Visit this group at http://groups.google.com/group/nhusers <
> http://groups.google.com/group/nhusers> .
> > For more options, visit https://groups.google.com/groups/opt_out<
> https://groups.google.com/groups/opt_out> .
> >
> >
> >
> >
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "nhusers" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to [email protected] <javascript:>.
> > To post to this group, send email to [email protected]<javascript:>.
>
> > Visit this group at http://groups.google.com/group/nhusers.
> > For more options, visit https://groups.google.com/groups/opt_out.
> >
> >
> >
> >
> > --
> > You received this message because you are subscribed to a topic in the
> Google Groups "nhusers" group.
> > To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/nhusers/OLXzSw0sU2s/unsubscribe.
> > To unsubscribe from this group and all its topics, send an email to
> [email protected] <javascript:>.
> > To post to this group, send email to [email protected]<javascript:>.
>
> > Visit this group at http://groups.google.com/group/nhusers.
> > For more options, visit https://groups.google.com/groups/opt_out.
> >
> >
>
> --
> You received this message because you are subscribed to the Google Groups
> "nhusers" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected] <javascript:>.
> To post to this group, send email to [email protected] <javascript:>
> .
> Visit this group at http://groups.google.com/group/nhusers.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>
--
You received this message because you are subscribed to the Google Groups
"nhusers" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/nhusers.
For more options, visit https://groups.google.com/groups/opt_out.
