NSXMLElement and namespaces
Can anybody help me understand how namespaces works with NSXMLNode etc. There is the method + [NSXMLNode elementWithName:(NSString *)name URI:(NSString *)URI] Which takes an namespace URI, but doesn't seem to use it. I have seems an example from google where they pass the namespace URI and then use a name which uses the namespace prefix as part of the name, for exmaple [NSXMLNode elementWithName:@xsl:value-of URI:@http://www.w3.org/1999/XSL/Transform;]; If you have to add the prefix to the name then what is the point of the URI argument. Nathan Day http://homepage.mac.com/nathan_day/ ___ 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: Terminating subtasks reliably
Call getppid, set up the kevent listener, then before you actually block in kevent, call getppid *again*. If the answer matches the first call, then you can go ahead and call kevent. If the answer doesn't match, you've hit the race condition you outline here, your parent is dead, and you can exit immediately. If the parent quits after the second getppid but before the call to kevent, you should still get the exit notification because you registered it before the parent quit. Ah - that should do it. I was skeptical though, so I took a peek at the kernel's exiting-process code (http://www.opensource.apple.com/source/xnu/xnu-1504.3.12/bsd/kern/kern_exit.c); indeed it looks like this technique is free from races, due to proc_exit() both issuing the NOTE_EXIT event and putting the exiting process in a reapable state _after_ all children of the exiting process have been reparented by launchd. For the archives: http://pastie.org/901581 ___ 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: iPhone CoreData TableView not updating (solved)
I found it: The .h was @interface AdresViewController : UITableViewController. I changed this to @interface AdresViewController : UIViewController and it now does work... ;-) On 3 apr 2010, at 06:08, Arnold Nefkens wrote: Hello List, I'm a newbie on iPhone Programming, so please bear with me. I did the first 7 chapters of More iPhone 3 Development, tackling iPhone SDK3 from Apress regarding the use of CoreData. In these 7 chapters a lot is explained and finally a series of classes and categories are being build that one can use as a Generic Controller for editing data stored in CoreData. So I bult a new application where I inserted these classes, and created a new viewController for my specific needs. Almost everything works, except that the tableView is not updated when I create a new item for in the DB, The item is however created, but only visible if I quit the App and start it again. Apparently something is not right. I double checked the 4 NSFetechedResult delegates, but it just does not work. I tried to insert [self.tableView reloadData] on a number of places, but to no avail. Can someone of you check my ViewController code? And point me in the right direction where I'm missing the ball? I'll send you the code off-list Your help and effort is much appreciated. Kind regards, Arnold Nefkens ___ 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/lists%40nefkens-ict.nl This email sent to li...@nefkens-ict.nl ___ 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
CGPoint and KVO
I have a property which is a CGPoint and I'm observing it. I didn't really know what to expect in the change dictionary (I have NSKeyValueObservingOld as the observation flags) so I stuck in a breakpoint and went looking. After messing about in the debugger when the property was changed I found the old value was an NSConcreteValue and the following code appears to work to extract the CGPoint from it CGPoint oldPoint; id oldValue = [ change valueForKey:NSKeyValueChangeOld ]; [ (NSValue*)oldValue getValue:oldPoint ] Is this correct? I've failed to find anything much in the KVO documentation about CGPoint or how I should expect to receive structs or other primitives. This is iPhone OS (incase that makes a difference). ___ 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: CGPoint and KVO
On 04/04/2010, at 1:40 AM, Roland King wrote: I have a property which is a CGPoint and I'm observing it. I didn't really know what to expect in the change dictionary (I have NSKeyValueObservingOld as the observation flags) so I stuck in a breakpoint and went looking. After messing about in the debugger when the property was changed I found the old value was an NSConcreteValue and the following code appears to work to extract the CGPoint from it CGPoint oldPoint; id oldValue = [ change valueForKey:NSKeyValueChangeOld ]; [ (NSValue*)oldValue getValue:oldPoint ] Is this correct? I've failed to find anything much in the KVO documentation about CGPoint or how I should expect to receive structs or other primitives. In the case of NSPoint/CGPoint: CGPoint oldPoint = [oldValue pointValue]; This is iPhone OS (incase that makes a difference). ___ 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/kiel.gillard%40gmail.com This email sent to kiel.gill...@gmail.com ___ 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: CGPoint and KVO
Thanks pointValue didn't work on iPhone OS but CGPointValue did, luckily, as that's the one I needed. That seems to be a UIKit extension. I've switched to that. was my original method (apart from being clunky) wrong? It did work. On 03-Apr-2010, at 10:43 PM, Kiel Gillard wrote: On 04/04/2010, at 1:40 AM, Roland King wrote: I have a property which is a CGPoint and I'm observing it. I didn't really know what to expect in the change dictionary (I have NSKeyValueObservingOld as the observation flags) so I stuck in a breakpoint and went looking. After messing about in the debugger when the property was changed I found the old value was an NSConcreteValue and the following code appears to work to extract the CGPoint from it CGPoint oldPoint; id oldValue = [ change valueForKey:NSKeyValueChangeOld ]; [ (NSValue*)oldValue getValue:oldPoint ] Is this correct? I've failed to find anything much in the KVO documentation about CGPoint or how I should expect to receive structs or other primitives. In the case of NSPoint/CGPoint: CGPoint oldPoint = [oldValue pointValue]; This is iPhone OS (incase that makes a difference). ___ 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/kiel.gillard%40gmail.com This email sent to kiel.gill...@gmail.com ___ 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: CGPoint and KVO
The main issue with the original code is that it assumes that the value is a CGPoint. If it were anything smaller, you'd get garbage values in your point, and if it were any larger, you'd be stomping on memory as you ran off the end of your CGPoint variable. Any time you use -[NSValue getValue:], you should check to make sure that the NSValue represents the correct type. Sent from my iPad On Apr 3, 2010, at 7:52, Roland King r...@rols.org wrote: Thanks pointValue didn't work on iPhone OS but CGPointValue did, luckily, as that's the one I needed. That seems to be a UIKit extension. I've switched to that. was my original method (apart from being clunky) wrong? It did work. On 03-Apr-2010, at 10:43 PM, Kiel Gillard wrote: On 04/04/2010, at 1:40 AM, Roland King wrote: I have a property which is a CGPoint and I'm observing it. I didn't really know what to expect in the change dictionary (I have NSKeyValueObservingOld as the observation flags) so I stuck in a breakpoint and went looking. After messing about in the debugger when the property was changed I found the old value was an NSConcreteValue and the following code appears to work to extract the CGPoint from it CGPoint oldPoint; id oldValue = [ change valueForKey:NSKeyValueChangeOld ]; [ (NSValue*)oldValue getValue:oldPoint ] Is this correct? I've failed to find anything much in the KVO documentation about CGPoint or how I should expect to receive structs or other primitives. In the case of NSPoint/CGPoint: CGPoint oldPoint = [oldValue pointValue]; This is iPhone OS (incase that makes a difference). ___ 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/kiel.gillard%40gmail.com This email sent to kiel.gill...@gmail.com ___ 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/clarkcox3%40gmail.com This email sent to clarkc...@gmail.com ___ 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: iPhone CoreData TableView not updating
I did the first 7 chapters of More iPhone 3 Development, tackling iPhone SDK3 from Apress regarding the use of CoreData. In these 7 chapters a lot is explained and finally a series of classes and categories are being build that one can use as a Generic Controller for editing data stored in CoreData. So I bult a new application where I inserted these classes, and created a new viewController for my specific needs. Almost everything works, except that the tableView is not updated when I create a new item for in the DB, The item is however created, but only visible if I quit the App and start it again. Apparently something is not right. I double checked the 4 NSFetechedResult delegates, but it just does not work. I tried to insert [self.tableView reloadData] on a number of places, but to no avail. Have you tried starting a new project from the template ? That produces a completely functional Core Data application you can experiment with. I'm not familiar with the book, it's possible there's a bug in their sample code. If you're having problems with the NSFetchedResultsController, please note that the cache is *persistent* across application runs. The NSFetchRequest is a read only property. You should not mutate it. If you change the NSFetchRequest, NSPredicate (or the varargs), or NSSortDescriptor in any way, the cache will be invalid. In 3.1, this kinda usually worked anyway. In 3.2 and later, the caching is more aggressive and produces much faster launch times for FRC with complex string queries. This also means that buggy code that got away with it on 3.1 will no longer if it's recompiled against the 3.2 SDK (3.1 binaries still run fine) You may find the behavior more intuitive if you opt out with a nil cache name. - Ben ___ 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: Invalidated managed objects
When I create a document, save it, then save as, then save as again, it
duplicates the persistent store, so the managed objects I have been using in
my application are all invalidated.
Now there are a whole lot of places in my application where I have KVO set up
on properties of the managed objects, and some places where I have the
managed objects set as instance variables of my objects. I was not expecting
them to be invalidated by the save as operation.
They are not invalidated as part of Save. They are as part of Save As since
that creates a new document, with a new persistent store, a new coordinator,
new pretty much everything. Save As is creating a duplicate, so the original
content still exists. However, the UI needs to be bound to the new content.
Think of the behavior of TextEdit. Save As is like close old, duplicate, open
new
And created a method to refresh my data:
- (void)managedObjectsChanged:(NSNotification *)notification {
if ([[notification userInfo] objectForKey:NSInvalidatedObjectsKey]) {
NSSet *objects = [[notification userInfo]
objectForKey:NSInvalidatedObjectsKey];
for (NSManagedObject *obj in objects) {
[[self managedObjectContext] refreshObject:obj
mergeChanges:YES];
}
} else if ([[notification userInfo]
objectForKey:NSInvalidatedAllObjectsKey]) {
for (NSManagedObject *obj in [[self managedObjectContext]
registeredObjects]) {
[[self managedObjectContext] refreshObject:obj
mergeChanges:YES];
}
}
}
I have confirmed that this is called in the save/save as/save as scenario,
with the NSInvalidatedAllObjectsKey, and my object is getting sent the
refreshObject message...But when I go to access my data, it still tells me
that it has been invalidated. Am I doing something wrong here?
Yes. You cannot resurrect invalidated objects. They are toast. That's why
you're getting an exception. Nor would you want to in this case as they all
represent content from the old (closed) document not the new saved as document.
You need to toss all these references and then go through the regular I just
opened a new document code path for your newly saved document to reconstruct
the KVO observations.
The canonical solution is to tell your controller objects like
NSArrayController to refetch from the new document. It sounds like you're
fighting the document based Save As behavior. It's close the existing
document, save the current state to a new document, open new document
- Ben
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Re: NSPredicate/NSExpression - can they solve this Core Data problem?
They are noted in the NSExpression.h header with API to create them and a comment to their functionality. - Ben Is the use of SUBQUERY() documented anywhere? The only mention I've seen of it is in the reserved keywords section of the Predicate Format String Syntax guide. Dave On Apr 2, 2010, at 3:42 PM, Ben Trumbull wrote: NSComparisonPredicate* exprPred = (NSComparisonPredicate*)[NSPredicate predicateWithFormat:@SUBQUERY(self, $key, %...@.$key != nil) == 0, obj]; NSExpression* expr = [exprPred leftExpression]; NSLog(@expression subquery results = %@, [expr expressionValueWithObject:keys context:nil]); ___ 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
What is the runtime context of an event tap?
When an event tap is created using CGEventTapCreate, which process, or thread actually runs the callback function? The one which created the tap, the first responder, ...? Thanks in advance, Pat. -- Pat Wilson mailto:p...@ieee.org ___ 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
How do I get a file reference w/o relying on the path?
I want to store a reference to a file in an ivar that will allow the user to change the file's name and/or the directory (i.e. the path) and still allow me to access it. I don't want to create a file (like an ailas). I need to store the file reference in a variable so I can open the file no matter where the user moves it or renames it. For those of you who know REALbasic I can do this easily with FolderItem.GetSaveInfo. How can I do this in Cocoa? Thanks___ 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: Invalidated managed objects
On Apr 3, 2010, at 12:05, Ben Trumbull wrote: The canonical solution is to tell your controller objects like NSArrayController to refetch from the new document. It sounds like you're fighting the document based Save As behavior. It's close the existing document, save the current state to a new document, open new document Do you mean fighting the NSPersistentDocument Save As behavior? My understanding is that close the existing document, save the current state to a new document, open new document is *not* the semantics of plain NSDocument Save As -- the whole point being that transient state is preserved across a Save As. No NSDocument-based (non-NSPersistentDocument-based) application is required to discard all of its in-memory object references after doing a Save As, as far as I'm aware. ___ 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: What is the runtime context of an event tap?
On Apr 3, 2010, at 5:16 PM, Pat Wilson wrote: When an event tap is created using CGEventTapCreate, which process, or thread actually runs the callback function? The one which created the tap, the first responder, ...? The first responder isn't a thread, process, or runtime/execution context. That aspect of your question doesn't make any sense, just so you know. The documentation for CGEventTapCreate says: Your callback function is invoked from the run loop to which the event tap is added as a source. The thread safety of the callback is defined by the run loop’s environment. Since a run loop is directly associated to a thread, you control which thread the callback is called on. If you add the run loop source for the returned Core Foundation mach port to the current run loop, then the callback will be called on the current thread. If you add it to the main run loop, then it will be called on the main thread. Etc. Regards, Ken ___ 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: How do I get a file reference w/o relying on the path?
On Apr 3, 2010, at 5:20 PM, Brad Stone wrote: I want to store a reference to a file in an ivar that will allow the user to change the file's name and/or the directory (i.e. the path) and still allow me to access it. I don't want to create a file (like an ailas). I need to store the file reference in a variable so I can open the file no matter where the user moves it or renames it. FSRefs have the property you desire. As of Snow Leopard, though, the new recommended technique is to use a file reference NSURL. Check the NSURL documentation and also: http://developer.apple.com/mac/library/documentation/cocoa/conceptual/LowLevelFileMgmt/Articles/FileManagementNSURL.html Note that an alias _record_ is different from an alias _file_. An alias record is data in memory and is suitable for this purpose, but perhaps overkill. As of Snow Leopard, alias records are deprecated in favor of bookmark data, but, again, it's probably overkill. (Both alias records and bookmark data are more suitable if the reference is to be persisted for use by a later process. Also, both can apply more robust searching heuristics to find an appropriate file even if it isn't the original. For example, if the original is deleted and replaced with a new file of the same name.) Cheers, Ken ___ 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
Two text fields, one outlet?
Is it possible to link multiple NSTextFields to one outlet? I have three views - one of A items, one of B items, and one of both A and B items. So the text boxes in the A view also exists in the AB view, and the value needs to be able to appear in both, though not at the same time. I have a method that calculates values and sets the textbox values (or label values, same concept) using an outlet, but I don't want it to set 2 outlets, I want it to just set 1. Is this possible using outlets or bindings?? Or is there a way I can place two NSViews into one NSView so there's only one copy of everything? Thanks... ___ 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: How do I get a file reference w/o relying on the path?
Very interesting. According to the documentation if I want to store the reference and want it to persist after a reboot I need to do a bookmark. You should not store or archive file reference URLs. A file’s ID may be different for different boots of the operating system. If you need to store a URL, see “Working with Bookmarks and Aliases.” THANK YOU so much for pointing me in the correct direction. On Apr 3, 2010, at 6:55 PM, Ken Thomases wrote: On Apr 3, 2010, at 5:20 PM, Brad Stone wrote: I want to store a reference to a file in an ivar that will allow the user to change the file's name and/or the directory (i.e. the path) and still allow me to access it. I don't want to create a file (like an ailas). I need to store the file reference in a variable so I can open the file no matter where the user moves it or renames it. FSRefs have the property you desire. As of Snow Leopard, though, the new recommended technique is to use a file reference NSURL. Check the NSURL documentation and also: http://developer.apple.com/mac/library/documentation/cocoa/conceptual/LowLevelFileMgmt/Articles/FileManagementNSURL.html Note that an alias _record_ is different from an alias _file_. An alias record is data in memory and is suitable for this purpose, but perhaps overkill. As of Snow Leopard, alias records are deprecated in favor of bookmark data, but, again, it's probably overkill. (Both alias records and bookmark data are more suitable if the reference is to be persisted for use by a later process. Also, both can apply more robust searching heuristics to find an appropriate file even if it isn't the original. For example, if the original is deleted and replaced with a new file of the same name.) Cheers, Ken ___ 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: Invalidated managed objects
Wow, this is huge! Obviously the user doesn't expect the document to disappear and a new one open up just because they did a Save As operation, so I would have to go through every single part of the application, work out every reference to a managed object, and either throw them away or fetch new ones, and also lose the undo stack, and I'm not sure how I would keep my current selections in the array controllers and recreate all my other non-persistent state so that the user doesn't lose what they're doing. On 04/04/2010, at 5:05 AM, Ben Trumbull wrote: They are not invalidated as part of Save. They are as part of Save As since that creates a new document, with a new persistent store, a new coordinator, new pretty much everything. Save As is creating a duplicate, so the original content still exists. However, the UI needs to be bound to the new content. Think of the behavior of TextEdit. Save As is like close old, duplicate, open new If I was doing this just with ordinary objects, doing a Save As would not affect the objects I am working with at all. Taking the example of TextEdit, it does not lose my selection, reload my window, or lose my undo stack when I do a Save As. Logically for the user, they are still working on the same document - it just happens to be stored in a different location. If we're thinking of a layered application architecture, the physical location of the file shouldn't affect the objects at a higher layer, IMHO - but that's just philosophical discussion - I need to get to a solution for this problem. Yes. You cannot resurrect invalidated objects. They are toast. That's why you're getting an exception. Nor would you want to in this case as they all represent content from the old (closed) document not the new saved as document. You need to toss all these references and then go through the regular I just opened a new document code path for your newly saved document to reconstruct the KVO observations. This might be manageable to fix (but very time consuming) for instance variables, but I also have various arrays, dictionaries, array controllers etc etc that hold references to my managed objects too. I guess I really don't get the design pattern for this. Trying to keep the UI layer as separate as possible from the model, I have lots of KVO to keep the UI up to date with the changes to the data. I was not expecting to have to break those KVO connections and have to re-establish them with new objects, and am not sure what the impact of this will be, since some of them use the initial option to set up state in the non-persistent side of things. In one class, I have over 100 of these, and many other classes have quite a few that will have to be dealt with too. I'm going to have to take a good long hard look at this to see whether this is possible to do with a reasonable amount of effort in my application, or whether to ditch core data. I probably have literally hundreds of places in my application where it has references to managed objects. I had no idea this was a bad thing, and I don't recall it being mentioned anywhere in the documentation. In fact the NSPersistentDocument core data tutorial has a reference to the managed object stored in the document. I haven't actually built that entire project to see whether it would have Save As problems on the second save as or load and save as, but I guess it would. Is there some documentation somewhere on how this is supposed to be done in the architecture? Is there a working example somewhere based on NSPersistentDocument and NSAtomicStore? For me to get this far into my application development and find out that managed objects are really transient in this sense, and that I must not hold any reference to them, or if I do, make sure I can handle the need to re-fetch them in their entirety as completely new objects, and maintain the current state as far as the user is concerned...well I think I must be massively on the wrong track as far as how you should be using core data objects is concerned, and would really like to see some complete working examples of how to do this properly. The canonical solution is to tell your controller objects like NSArrayController to refetch from the new document. It sounds like you're fighting the document based Save As behavior. It's close the existing document, save the current state to a new document, open new document - Ben I have just checked, and 26 of my nib files have array controllers in them, but I'm not sure how they are all referenced, in order to force them to reload, or how to get them to keep their selection so there is no change for the user. I don't feel that I can adequately deal with this until I understand the intended design pattern for an application based on NSPersistentDocument and NSAtomicStore, and see how the necessary updates can happen without affecting the user. TIA
Re: Invalidated managed objects
On Apr 3, 2010, at 5:07 PM, Gideon King wrote:
Wow, this is huge! Obviously the user doesn't expect the document to
disappear and a new one open up just because they did a Save As operation
I have I'm afraid led you astray. The invalidated objects are not coming from
the Save As operation. The managed objects in the MOC bound to the
NSPersistentDocument, and any other MOCs bound to that same PSC will keep the
NSManagedObjects themselves in sync with the underlying document even as it is
remapped to a new file. I'll send you a sample project from the template that
logs the notifications from NSManagedObjectContext and
NSPersistentStoreCoordinator. The NSManagedObject pointers remain undisturbed.
2010-04-03 18:13:41.110 testDocs[14260:a0f] PSC changed: {
changedUUID = (
NSSQLCore: 0x1025513e0,
NSSQLCore: 0x103051890,
(
0x1025a4bc0
x-coredata://7401BACF-50F9-4699-8B65-520963A9B084/Entity/p3,
0x103055bc0
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p1,
0x102504fb0
x-coredata://7401BACF-50F9-4699-8B65-520963A9B084/Entity/p2,
0x103051d40
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p3,
0x102598810
x-coredata://7401BACF-50F9-4699-8B65-520963A9B084/Entity/p1,
0x1004eeb10
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p2
)
);
}
2010-04-03 18:13:41.112 testDocs[14260:a0f] PSC changed. Registered objects =
{(
NSManagedObject: 0x1004db090 (entity: Entity; id: 0x103051d40
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p3 ; data: {
name = baz;
}),
NSManagedObject: 0x1004db120 (entity: Entity; id: 0x103055bc0
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p1 ; data: {
name = foo;
}),
NSManagedObject: 0x1004daea0 (entity: Entity; id: 0x1004eeb10
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p2 ; data: {
name = zap;
})
)}
2010-04-03 18:13:53.604 testDocs[14260:a0f] PSC changed: {
changedUUID = (
NSSQLCore: 0x103051890,
NSSQLCore: 0x103062860,
(
0x10305b680
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p1,
0x10306a890
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p1,
0x10305b3c0
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p2,
0x10306aa80
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p2,
0x1030681e0
x-coredata://9D960070-9CAE-4BDD-9EDF-99ACCD83AF7F/Entity/p3,
0x10306ae20
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p3
)
);
}
2010-04-03 18:13:53.604 testDocs[14260:a0f] PSC changed. Registered objects =
{(
NSManagedObject: 0x1004db090 (entity: Entity; id: 0x10306ae20
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p3 ; data: {
name = baz;
}),
NSManagedObject: 0x1004db120 (entity: Entity; id: 0x10306a890
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p1 ; data: {
name = foo;
}),
NSManagedObject: 0x1004daea0 (entity: Entity; id: 0x10306aa80
x-coredata://381F89A2-9204-45E8-850B-1CED8022E32E/Entity/p2 ; data: {
name = zap;
})
)}
There are no invalidate managed objects if you create a Core Data document
based app from the Xcode template and then perform Save As. I'll take another
look at your sample project.
- Ben
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Re: Invalidated managed objects
Phew, that's a relief. I'll look forward to hearing what I'm doing wrong in my sample project then. Regards Gideon On 04/04/2010, at 11:22 AM, Ben Trumbull wrote: On Apr 3, 2010, at 5:07 PM, Gideon King wrote: Wow, this is huge! Obviously the user doesn't expect the document to disappear and a new one open up just because they did a Save As operation I have I'm afraid led you astray. The invalidated objects are not coming from the Save As operation. The managed objects in the MOC bound to the NSPersistentDocument, and any other MOCs bound to that same PSC will keep the NSManagedObjects themselves in sync with the underlying document even as it is remapped to a new file. I'll send you a sample project from the template that logs the notifications from NSManagedObjectContext and NSPersistentStoreCoordinator. The NSManagedObject pointers remain undisturbed. ___ 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: How do I get a file reference w/o relying on the path?
Ken, he asked for a reference that wouldn't break if the file were moved or
renamed. Neither FSrefs nor URLs have that property.
Brad, what you want is a bookmark (in 10.6) or an alias reference. Aliases
didn't have a Cocoa API until 10.6, but the procedural API isn't hard to use.
--Jens {via iPad}
On Apr 3, 2010, at 3:55 PM, Ken Thomases k...@codeweavers.com wrote:
On Apr 3, 2010, at 5:20 PM, Brad Stone wrote:
I want to store a reference to a file in an ivar that will allow the user to
change the file's name and/or the directory (i.e. the path) and still allow
me to access it. I don't want to create a file (like an ailas). I need to
store the file reference in a variable so I can open the file no matter
where the user moves it or renames it.
FSRefs have the property you desire. As of Snow Leopard, though, the new
recommended technique is to use a file reference NSURL. Check the NSURL
documentation and also:
http://developer.apple.com/mac/library/documentation/cocoa/conceptual/LowLevelFileMgmt/Articles/FileManagementNSURL.html
Note that an alias _record_ is different from an alias _file_. An alias
record is data in memory and is suitable for this purpose, but perhaps
overkill.
As of Snow Leopard, alias records are deprecated in favor of bookmark data,
but, again, it's probably overkill. (Both alias records and bookmark data
are more suitable if the reference is to be persisted for use by a later
process. Also, both can apply more robust searching heuristics to find an
appropriate file even if it isn't the original. For example, if the original
is deleted and replaced with a new file of the same name.)
Cheers,
Ken
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Re: Two text fields, one outlet?
No, an outlet is a single variable that can point to only one object at a time.
(You can't use NSArrays as outlet values.) you'll need multiple outlets, or one
view you move between two superviews.
--Jens {via iPad}
On Apr 3, 2010, at 4:22 PM, Jenny M safflo...@gmail.com wrote:
Is it possible to link multiple NSTextFields to one outlet? I have
three views - one of A items, one of B items, and one of both A and B
items. So the text boxes in the A view also exists in the AB view,
and the value needs to be able to appear in both, though not at the
same time. I have a method that calculates values and sets the textbox
values (or label values, same concept) using an outlet, but I don't
want it to set 2 outlets, I want it to just set 1.
Is this possible using outlets or bindings??
Or is there a way I can place two NSViews into one NSView so there's
only one copy of everything?
Thanks...
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Re: Invalidated managed objects
On Apr 3, 2010, at 6:25 PM, Gideon King wrote: Phew, that's a relief. I'll look forward to hearing what I'm doing wrong in my sample project then. Regards Gideon On 04/04/2010, at 11:22 AM, Ben Trumbull wrote: On Apr 3, 2010, at 5:07 PM, Gideon King wrote: Wow, this is huge! Obviously the user doesn't expect the document to disappear and a new one open up just because they did a Save As operation I have I'm afraid led you astray. The invalidated objects are not coming from the Save As operation. The managed objects in the MOC bound to the NSPersistentDocument, and any other MOCs bound to that same PSC will keep the NSManagedObjects themselves in sync with the underlying document even as it is remapped to a new file. I'll send you a sample project from the template that logs the notifications from NSManagedObjectContext and NSPersistentStoreCoordinator. The NSManagedObject pointers remain undisturbed. Okay. The invalidations are coming from the PSC when it removes the old store. At this point it's already added the new store, and it's already told the MOC to switch all the objectIDs from its MOs to point to the new store. The problem is that your custom store wasn't being honest about the objectIDs, it wasn't even saving them at all, so the remapping between the old and new store fails. At that point, the MOC still has objects from the old store in it, because the new store handed out random IDs and the mapping failed to find them. So I changed your save method to write out both the UUID and the string data so your store could properly reconstruct the cache node it loads. There was another subtle issue from your reusing the metadata dictionary to hold your row data. The problem is you set the metadata at unfortunate times, both before and after the store is created. Instead of changing it in -init (too soon) and in -load (too late), it works better to use -loadMetadata. This is a problem for you since you were overwriting the in memory metadata with the plist you wrote to disk which effectively caused the store to change it's UUID. The documentation isn't clear on this, so you shouldn't feel bad about missing this part. You also had -metadata spontaneously mutate the row data, which is bad. It's really important for stores to keep their UUID, and for them to hand back the same objectID for an object that they did when we asked before. Otherwise constructing a map from old ids to new ids and looking up stores by their UUID is kinda hard. I'll send you back the original and edited sample projects so you can diff them. - Ben ___ 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: Invalidated managed objects
Excellent, thanks for that. I thought that once a managed object ID had been
assigned, that newReferenceObjectForManagedObject: should always return the
same value, so I was regenerating it from the previous data instead of
generating a new one if it either had a temporary object id or no object id. I
will switch over my code to do this.
In my current implementation, I have a base class for all my managed objects
that has an id string (elementID) set in it. The only times it is persisted is
for objects that I need to refer to in relationships. This means I can
regenerate the value from the managed objects if necessary, so my new method
will look like this:
- (id)newReferenceObjectForManagedObject:(NSManagedObject*)managedObject {
NSManagedObjectID *oid = [managedObject objectID];
if ((oid == nil) || [oid isTemporaryID]) {
NSString *aUUID = [NMFoundation generateUUID];
managedObject.elementID = aUUID;
}
return [[NSString alloc] initWithString:managedObject.elementID];
}
It's really helpful to have your input on this - I spent forever looking for
this, and didn't see it because I didn't fully understand when the reference
object needed to be the same and when it needed to be different.
There is only one area of my code where this will cause an issue, where I
pre-generate some of the xml for my file using some references to some managed
objects. I'm sure I'll be able to find a way around this though.
Hopefully that will resolve that issue.
Also, I had not noticed the loadMetadata: method, so was just creating it in
the init for new files, or in my load method for existing ones. I will have to
do a bit of work to change that to load using loadMetadata: since I will have
to extract the file from a zip file separately from the main load method which
already unzips to a temporary folder. Not a biggie though.
Hopefully on the home straight now...
Regards
Gideon
Okay. The invalidations are coming from the PSC when it removes the old
store. At this point it's already added the new store, and it's already told
the MOC to switch all the objectIDs from its MOs to point to the new store.
The problem is that your custom store wasn't being honest about the
objectIDs, it wasn't even saving them at all, so the remapping between the
old and new store fails. At that point, the MOC still has objects from the
old store in it, because the new store handed out random IDs and the mapping
failed to find them.
So I changed your save method to write out both the UUID and the string data
so your store could properly reconstruct the cache node it loads.
There was another subtle issue from your reusing the metadata dictionary to
hold your row data. The problem is you set the metadata at unfortunate
times, both before and after the store is created. Instead of changing it in
-init (too soon) and in -load (too late), it works better to use
-loadMetadata. This is a problem for you since you were overwriting the in
memory metadata with the plist you wrote to disk which effectively caused the
store to change it's UUID. The documentation isn't clear on this, so you
shouldn't feel bad about missing this part. You also had -metadata
spontaneously mutate the row data, which is bad.
It's really important for stores to keep their UUID, and for them to hand
back the same objectID for an object that they did when we asked before.
Otherwise constructing a map from old ids to new ids and looking up stores by
their UUID is kinda hard.
I'll send you back the original and edited sample projects so you can diff
them.
- Ben
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Re: Two text fields, one outlet?
On Apr 3, 2010, at 6:22 PM, Jenny M wrote: Is it possible to link multiple NSTextFields to one outlet? I have three views - one of A items, one of B items, and one of both A and B items. So the text boxes in the A view also exists in the AB view, and the value needs to be able to appear in both, though not at the same time. I have a method that calculates values and sets the textbox values (or label values, same concept) using an outlet, but I don't want it to set 2 outlets, I want it to just set 1. Is this possible using outlets or bindings?? Or is there a way I can place two NSViews into one NSView so there's only one copy of everything? Instead of fretting about the views, just make two NSString (or NSAttributedString) properties in some object. Then make an NSObjectController with that object as its “content” outlet, and bind all the “A” views to the “A” property and the “B” views to the “B” property. This way the views will always be synced up, but you won’t have to bother with outlets at all. Charles___ 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: Invalidated managed objects
On Apr 3, 2010, at 9:44 PM, Gideon King wrote:
Excellent, thanks for that. I thought that once a managed object ID had been
assigned, that newReferenceObjectForManagedObject: should always return the
same value, so I was regenerating it from the previous data instead of
generating a new one if it either had a temporary object id or no object id.
I will switch over my code to do this.
Uhm, that's not exactly what I said. It should look something like:
- (id)newReferenceObjectForManagedObject:(NSManagedObject *)managedObject {
id result = nil;
NSManagedObjectID* oid = [managedObject objectID];
if ((oid == nil) || [oid isTemporaryID]) {
CFUUIDRef uuidRef = CFUUIDCreate(NULL);
CFStringRef uuidStringRef = CFUUIDCreateString(NULL, uuidRef);
result = [[NSString alloc]
initWithString:(NSString*)uuidStringRef];
CFRelease(uuidStringRef);
CFRelease(uuidRef);
} else {
result = [[self referenceObjectForObjectID:oid] retain];
}
return result;
}
although all the Core Data stores use a single 64 bit integer with the current
seed value stored in the metadata instead of UUIDs.
In my current implementation, I have a base class for all my managed objects
that has an id string (elementID) set in it. The only times it is persisted
is for objects that I need to refer to in relationships. This means I can
regenerate the value from the managed objects if necessary, so my new method
will look like this:
The objectID value (referenceObject) needs to be the same every time you load
the document. If you open the document multiple times, and give the same
objects different objectIDs, badness happens. For Save As, we're generating a
dictionary of old IDs - new IDs. When we add the new store to the
coordinator, if the store hands back random values for the migrated objects,
then the MOC can't fix its MOs to point to the new store's cache nodes.
if you:
(1) open the document
(2) fetch all the objects into array 'results' (with a sort ordering)
(3) NSLog(@results = %@, [results valueForKey:@objectID]),
(4) close the document
(5) repeat steps 1-4
(6) compare the 2 logs
If the strings don't match, you're SOL.
There is only one area of my code where this will cause an issue, where I
pre-generate some of the xml for my file using some references to some
managed objects. I'm sure I'll be able to find a way around this though.
Hopefully that will resolve that issue.
Also, I had not noticed the loadMetadata: method, so was just creating it in
the init for new files, or in my load method for existing ones. I will have
to do a bit of work to change that to load using loadMetadata: since I will
have to extract the file from a zip file separately from the main load method
which already unzips to a temporary folder. Not a biggie though.
You don't have to use it, but for the sample project you sent that conflated
the metadata and raw data, it was the best way to avoid nuking the already
loaded metadata when you loaded the raw data. It's probably all around better
though.
- Ben
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Re: Invalidated managed objects
Ah, so when it says the method must derive the reference object from the managed object’s values it is talking about the managed object's persisted values. So I could get rid of my extra attribute in my managed object class and just set my UUID using a method similar to what you define below, and then just persist that on all my objects. It is possible that the file could be edited in the Windows version of the application, or may be imported through an importer that doesn't add the IDs, but I guess that wouldn't matter since I would set it the first time it was asked for, and I would persist it after that. Regards Gideon The objectID value (referenceObject) needs to be the same every time you load the document. If you open the document multiple times, and give the same objects different objectIDs, badness happens. For Save As, we're generating a dictionary of old IDs - new IDs. When we add the new store to the coordinator, if the store hands back random values for the migrated objects, then the MOC can't fix its MOs to point to the new store's cache nodes. if you: (1) open the document (2) fetch all the objects into array 'results' (with a sort ordering) (3) NSLog(@results = %@, [results valueForKey:@objectID]), (4) close the document (5) repeat steps 1-4 (6) compare the 2 logs If the strings don't match, you're SOL. ___ 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
