Mystery Key Value Coding Key

Posted by Stephen Furlani on Stack Overflow See other posts from Stack Overflow or by Stephen Furlani
Published on 2010-05-27T20:03:09Z Indexed on 2010/05/28 9:51 UTC
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Hello,

I'm attempting to load data from an undocumented API (OsiriX).

Getting the NSManagedObject like this: NSManagedObject *itemStudy = [[BrowserController databaseOutline] itemAtRow: [[BrowserController databaseOutline] selectedRow]];

works just fine.

But getting the NSManagedObject like this: seriesArray = [_context executeFetchRequest:request error:&error]; NSManagedObject *itemSeries = [seriesArray objectAtIndex:0];

Generates an error when I call [itemSeries valueForKey:@"type"]

2010-05-27 11:04:48.178 rcOsirix[27712:7b03] Exception: [<NSManagedObject 0xd30fd0> valueForUndefinedKey:]: the entity Series is not key value coding-compliant for the key "type".

This confuses me thoroughly. If I print the KVC values for itemSeries I get this list:

2010-05-27 11:04:48.167 rcOsirix[27712:7b03] KVC comment
2010-05-27 11:04:48.168 rcOsirix[27712:7b03] KVC date
2010-05-27 11:04:48.168 rcOsirix[27712:7b03] KVC dateAdded
2010-05-27 11:04:48.169 rcOsirix[27712:7b03] KVC dateOpened
2010-05-27 11:04:48.169 rcOsirix[27712:7b03] KVC displayStyle
2010-05-27 11:04:48.170 rcOsirix[27712:7b03] KVC id
2010-05-27 11:04:48.170 rcOsirix[27712:7b03] KVC modality
2010-05-27 11:04:48.170 rcOsirix[27712:7b03] KVC name
2010-05-27 11:04:48.171 rcOsirix[27712:7b03] KVC numberOfImages
2010-05-27 11:04:48.171 rcOsirix[27712:7b03] KVC numberOfKeyImages
2010-05-27 11:04:48.171 rcOsirix[27712:7b03] KVC rotationAngle
2010-05-27 11:04:48.172 rcOsirix[27712:7b03] KVC scale
2010-05-27 11:04:48.172 rcOsirix[27712:7b03] KVC seriesDICOMUID
2010-05-27 11:04:48.173 rcOsirix[27712:7b03] KVC seriesDescription
2010-05-27 11:04:48.173 rcOsirix[27712:7b03] KVC seriesInstanceUID
2010-05-27 11:04:48.173 rcOsirix[27712:7b03] KVC seriesSOPClassUID
2010-05-27 11:04:48.174 rcOsirix[27712:7b03] KVC stateText
2010-05-27 11:04:48.174 rcOsirix[27712:7b03] KVC thumbnail
2010-05-27 11:04:48.174 rcOsirix[27712:7b03] KVC windowLevel
2010-05-27 11:04:48.175 rcOsirix[27712:7b03] KVC windowWidth
2010-05-27 11:04:48.175 rcOsirix[27712:7b03] KVC xFlipped
2010-05-27 11:04:48.176 rcOsirix[27712:7b03] KVC xOffset
2010-05-27 11:04:48.176 rcOsirix[27712:7b03] KVC yFlipped
2010-05-27 11:04:48.176 rcOsirix[27712:7b03] KVC yOffset
2010-05-27 11:04:48.177 rcOsirix[27712:7b03] KVC mountedVolume
2010-05-27 11:04:48.177 rcOsirix[27712:7b03] KVC study
2010-05-27 11:04:48.178 rcOsirix[27712:7b03] KVC images

The KVC for itemStudy is this:

2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC accessionNumber
2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC comment
2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC date
2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC dateAdded
2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC dateOfBirth
2010-05-27 10:46:40.336 OsiriX[27266:a0f] KVC dateOpened
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC dictateURL
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC expanded
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC hasDICOM
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC id
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC institutionName
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC lockedStudy
2010-05-27 10:46:40.337 OsiriX[27266:a0f] KVC modality
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC name
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC numberOfImages
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC patientID
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC patientSex
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC patientUID
2010-05-27 10:46:40.338 OsiriX[27266:a0f] KVC performingPhysician
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC referringPhysician
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC reportURL
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC stateText
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC studyInstanceUID
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC studyName
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC windowsState
2010-05-27 10:46:40.339 OsiriX[27266:a0f] KVC albums
2010-05-27 10:46:40.340 OsiriX[27266:a0f] KVC series

If I use code:

NSDictionary *props = [[item entity] propertiesByName];
 for (NSString *s in [props allKeys]) {
  NSLog(@"KVC %@", s);
 }

Yet itemStudy throws no error if I call [itemStudy valueForKey:@"type"] when it should because there's no KVC for @"type"!!!

Granted, the objects are different but neither of them contain the key @"type" and they both should throw errors, yet the Osirix code Tests for both conditions:

if ([[item valueForKey:@"type"] isEqualToString:@"Series"]) {
...
}
if ([[item valueForKey:@"type"] isEqualToString:@"Study"]) {
...
}

And throws no errors. Yet when I load an NSManagedObject of the same exact model and entity @"Series" it throws the 'no key value' when passed into the conditions above.

Am I missing something? Both the superentity and subentities of itemSeries and itemStudy are nil so they don't inherit from something that has KVC @"type".

I'm totally at a loss as to explain what is going on.

--- EDIT ---

I know no one can explain what is going on... but maybe where to start looking? How would itemStudy have the extra KVC @"type" that doesn't show up in it's property list?

Thank you for your assistance,

-Stephen

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