Re: NSTableColumn value binding + keypath over a relationship
I'm going to take a stab in the dark and predict that you *don't* have rearranges content automatically checked for the array controller, I do. and that checking it will cause the error message to go away. It does not. Try unchecking it. http://stackoverflow.com/questions/1028700/core-data-strange-bindings-error-on-re-opening-a-document-help - Bryan ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSTableColumn value binding + keypath over a relationship
On Sep 30, 2009, at 10:22, Bryan Matteson wrote: I'm going to take a stab in the dark and predict that you *don't* have rearranges content automatically checked for the array controller, I do. and that checking it will cause the error message to go away. It does not. Try unchecking it. I tried it, did not help. Besides, I need automatic resorting (automatic at least from the user's point of view), and this is the cleanest way of doing it. http://stackoverflow.com/questions/1028700/core-data-strange-bindings-error-on-re-opening-a-document-help Similar behavior (not the same), and I am not getting any formatter related Console messages that are mentioned on that thread. I could be messing things up some other way though. Will try to isolate the issue. F ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
NSTableColumn value binding + keypath over a relationship
Hi all, I have been experiencing an error in my app that does not make sense... Here is the situation: A CoreData app. I have a table and one of it's columns' value bound to an array controller's arrangedObjects.group.title. The controller contains objects of the Note entity. Note relates to a Group (to-one), and the Group entity has a title attribute. Straightforward. Next to the table I have an outline view containing Groups. I have implemented drag and drop so that Notes can be dragged from their table to a different group in the outline view. However, when I have the above described table column present in the table, I get an error after dragging that says: Cannot remove an observer NSTableBinder 0x177eb0 for the key path group.name from FSNote 0x1ad240, most likely because the value for the key group has changed without an appropriate KVO notification being sent. Check the KVO-compliance of the FSNote class. I am quite certain that the Note class is KVO compliant for group, since I don't do anything to prevent it being, and it's a CoreData entity with @dynamic property generation. So, I am wondering, am I doing something wrong? It seems a reasonable thing to do, binding a column's value to the arrangedObjects.relationship.attribute key path, but maybe that is not allowed? I have managed to work around this by binding the column to arrangedObjects.group, and using a custom value transformer. This provides me with exactly the functionality I need, but I am still wondering about the mechanics, and if I am doing something wrong. Thanks in advance, F ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSTableColumn value binding + keypath over a relationship
On Sep 29, 2009, at 14:18, Stamenkovic Florijan wrote: A CoreData app. I have a table and one of it's columns' value bound to an array controller's arrangedObjects.group.title. The controller contains objects of the Note entity. Note relates to a Group (to-one), and the Group entity has a title attribute. Straightforward. Next to the table I have an outline view containing Groups. I have implemented drag and drop so that Notes can be dragged from their table to a different group in the outline view. However, when I have the above described table column present in the table, I get an error after dragging that says: Cannot remove an observer NSTableBinder 0x177eb0 for the key path group.name from FSNote 0x1ad240, most likely because the value for the key group has changed without an appropriate KVO notification being sent. Check the KVO-compliance of the FSNote class. I am quite certain that the Note class is KVO compliant for group, since I don't do anything to prevent it being, and it's a CoreData entity with @dynamic property generation. So, I am wondering, am I doing something wrong? It seems a reasonable thing to do, binding a column's value to the arrangedObjects.relationship.attribute key path, but maybe that is not allowed? The error message specifies group.name, not group.title. Do you maybe have a typo in one of your bindings in IB? KVO compliance doesn't necessarily come automatically, if you don't do anything to prevent it. In the case of a simple property, yes, *if* you update the property through the proper setter, the KVO notifications will occur automatically, but it's easy to get into a situation where the update doesn't happen when or as you think. It only gets more complicated when key paths are involved, instead of single keys. Also, keep in mind that a path like arrangedObjects.group.title is a fiction. arrangedObjects is an array, and each row of the column is bound to a different element of the array. arrangedObjects is the key path to the array property, group.title is the key path to each element. The binding is what bridges that difference -- there is more going on behind the scenes than just KVC. (Because of convenience behavior in NSArray, a key path like someArray.somePropertyOfEachArrayElement will actually return an array of property values when accessed via KVC, but that reference is not in itself KVO compliant.) ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSTableColumn value binding + keypath over a relationship
On Sep 29, 2009, at 17:37, Bryan Matteson wrote:
Cannot remove an observer NSTableBinder 0x177eb0 for the key path
group.name from FSNote 0x1ad240, most likely because the value
for the key group has changed without an appropriate KVO
notification being sent. Check the KVO-compliance of the FSNote
class.
Means exactly what it says. Somewhere you changed the value of a
group object without using KVC.
So, I am wondering, am I doing something wrong? It seems a
reasonable thing to do, binding a column's value to the
arrangedObjects.relationship.attribute key path, but maybe that
is not allowed?
It IS allowed, and the best way to go about it.
I have managed to work around this by binding the column to
arrangedObjects.group, and using a custom value transformer. This
provides me with exactly the functionality I need, but I am still
wondering about the mechanics, and if I am doing something wrong.
This is probably not correct.
Check your outlineView's delegate methods where you have implemented
drag and drop. Somewhere along the way you are changing a value
without using the mutators. If you can't find it, post the relevant
code (i.e. the all drag-and-drop related code from the outline view)
and I'll help you spot it.
Bryan, Quincey,
Thanks for your replies. As for the group.name vs. group.title
that Quincy mentions, it's a typo in the email, not in the project.
As for messing up / not using KVO properly, I suppose that somehow I
am not, but I don't see how. I have read most of the CoreData docs and
have experience with similar technologies (WebObjects), and am fairly
certain I am not doing anything obviously wrong... Also what is
interesting is that I can
As for what Bryan mentions, that I am changing an attribute in a non-
KVO-compliant way, I do not think so. In that sense the message I am
getting is a bit misleading (also note that it says ...most likely
because...)...
Bryan, you say that my workaround is probably not correct. Why? I
understand it is a long and not the-right-way, but the-right-way does
not seem to work for me at the moment.
As for the code in the outline view data source, here it is, I am not
changing the value without using the mutators, but perhaps it is
relevant:
- (BOOL)outlineView:(NSOutlineView*)outlineView
acceptDrop:(id NSDraggingInfo)info
item:(id)proposedParentItem
childIndex:(NSInteger)proposedChildIndex
{
NSPasteboard* pboard = [info draggingPasteboard];
NSArray* pboardTypes = [pboard types];
// Notes being dragged
if([pboardTypes containsObject:FSNoteIDURIsArrayPBType]){
// the group dragged to
NSManagedObject* group = [((NSTreeNode*)proposedParentItem)
representedObject];
// the URIs of Notes being dragged
NSArray* noteURIs = [NSKeyedUnarchiver
unarchiveObjectWithData:[pboard
dataForType:FSNoteIDURIsArrayPBType]];
NSUndoManager* um = [[group managedObjectContext] undoManager];
// relate the notes to the group dragged into
// do it as a single undoable op
[um beginUndoGrouping];
for(NSURL* noteURI in noteURIs){
// app delegate is the where the managed object URI - managed
object reference logic resides
FSNote* note = (FSNote*)[appDelegate
objectForURI:noteURI];
note.group = group;
}
[um endUndoGrouping];
return YES;
}
// accepting also other drag types (reordering of Groups contained in
the outline view), code that does that is here
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Re: NSTableColumn value binding + keypath over a relationship
On Sep 29, 2009, at 15:27, Stamenkovic Florijan wrote:
// the group dragged to
NSManagedObject* group = [((NSTreeNode*)proposedParentItem)
representedObject];
// the URIs of Notes being dragged
NSArray* noteURIs = [NSKeyedUnarchiver
unarchiveObjectWithData:[pboard
dataForType:FSNoteIDURIsArrayPBType]];
NSUndoManager* um = [[group managedObjectContext] undoManager];
// relate the notes to the group dragged into
// do it as a single undoable op
[um beginUndoGrouping];
for(NSURL* noteURI in noteURIs){
// app delegate is the where the managed object URI - managed
object reference logic resides
FSNote* note = (FSNote*)[appDelegate
objectForURI:noteURI];
note.group = group;
}
[um endUndoGrouping];
I dunno, this is where my head starts to hurt.
According to your error message, there was an observer of a Note
(well, FSNote) object for key path group.name. However, your binding
is via arrangedObjects. Now, although the array controller may be KVO
compliant for the property arrangedObjects, the arrangedObjects
array isn't itself KVO compliant for anything, because arrays just
aren't. So although 'note.group = group;' is generating the correct
notification, maybe it just isn't flowing through the array
controller to the binding mechanism.
I'm going to take a stab in the dark and predict that you *don't* have
rearranges content automatically checked for the array controller,
and that checking it will cause the error message to go away. (Or,
equivalently, you could send a rearrangeObjects message to the array
controller immediately after 'note.group = group;'.)
Alternatively, you could move to a small island in the Pacific and
forget you ever heard of NSArrayController. ;)
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Re: NSTableColumn value binding + keypath over a relationship
On Sep 29, 2009, at 19:21, Quincey Morris wrote:
On Sep 29, 2009, at 15:27, Stamenkovic Florijan wrote:
// the group dragged to
NSManagedObject* group = [((NSTreeNode*)proposedParentItem)
representedObject];
// the URIs of Notes being dragged
NSArray* noteURIs = [NSKeyedUnarchiver
unarchiveObjectWithData:[pboard
dataForType:FSNoteIDURIsArrayPBType]];
NSUndoManager* um = [[group managedObjectContext] undoManager];
// relate the notes to the group dragged into
// do it as a single undoable op
[um beginUndoGrouping];
for(NSURL* noteURI in noteURIs){
// app delegate is the where the managed object URI - managed
object reference logic resides
FSNote* note = (FSNote*)[appDelegate
objectForURI:noteURI];
note.group = group;
}
[um endUndoGrouping];
I dunno, this is where my head starts to hurt.
According to your error message, there was an observer of a Note
(well, FSNote) object for key path group.name.
I figured that out. And I am fairly sure it is a binding mediator
between the column and the array controller, because if I remove that
column, I don't get the error.
However, your binding is via arrangedObjects. Now, although the
array controller may be KVO compliant for the property
arrangedObjects, the arrangedObjects array isn't itself KVO
compliant for anything, because arrays just aren't. So although
'note.group = group;' is generating the correct notification, maybe
it just isn't flowing through the array controller to the binding
mechanism.
Hm... I am thinking something similar. However, it seems to me that
every item in the contents of an array controller is observed for
relevant paths. Which can be witnessed when binding a table column's
value to an attribute of an item in the controller. For example,
arrangedObjects.firstName in a Person. So, it seems that an array
controller provides KVO compliance for it's contents (arrangedObjects)
as well as for the properties of items in that array. My situation
seems to imply this too. If I bind to arrangedObjects.group, and use
a value transformer, I get both the correct behavior and updates in
the NSTableView resulting when I change a Note's group relationship.
Where it seems to fail is when stretching that path. Somehow the array
controller seems to be able to handle itemNoX.relationship, but not
itemNoX.relationship.attribute.
I'm going to take a stab in the dark and predict that you *don't*
have rearranges content automatically checked for the array
controller,
I do.
and that checking it will cause the error message to go away.
It does not.
(Or, equivalently, you could send a rearrangeObjects message to
the array controller immediately after 'note.group = group;'.)
I am not sure where you are going with this, but I have tried it, and
it does not change the behavior.
F
if nobody comes up with a you are doing this wrong, do it like this
by tomorrow I will try to isolate this in a small case. Maybe I am
causing this somewhere else in my code. I think not, but best to check.
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