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POCorruption of NSManagedObject-derived objects when property is accessed
primarykey
Id
10339067
data
AcceptedAnswerId
14635129
AnswerCount
2
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2012-04-26T18:14:53.630
FavoriteCount
0
LastActivityDate
2013-01-31T21:04:29.007
LastEditDate
2012-04-27T07:41:38.443
LastEditorUserId
72882
OwnerUserId
72882
ParentId
0
PostTypeId
1
Score
2
ViewCount
277
LastEditorDisplayName
text
Body
I have a class that at some point gets a bunch of data with a Core Data fetch and then inserts the objects, created in the usual Core Data way in XCode and therefore derived from <code>NSManagedObject</code>, into an <code>NSMutableSet</code>. Depending on how things work out, some of these objects might end up in several other sets. So far, so good. But then the following happens: <pre><code>NSMutableArray* anArray = [NSMutableArray alloc] init; [currentResults minus:previousResults]; // both are NSMutableSets for(MyObject* obj in currentResults) { [anArray addObject:[createAnnoFromMyObject:obj]]; // nastiness happens here } </code></pre> All <code>createAnnoFromMyObj:</code> does is pull data out of <code>obj</code> and return a object that implements <code>MKAnnotation</code>. The problem is that although I get an array of usable annotations, <code>currentResults</code>, <code>previousResults</code>, and any other objects that references any of the <code>MyObject</code>s that were touched by <code>createAnnoFromMyObject:</code> end up getting trashed. By trashed I mean that trying to access them results in an exception along the lines of <pre><code>-[MyObject beginningOfDocument]: unrecognized selector sent to instance... </code></pre> The same happens when trying to view any of these collections in the debugger pane with the <code>po</code> command. We tried regenerating <code>MyObject</code> in Core Data but no luck. There is very little mention of this <code>beginningOfDocument</code> selector on Google and we have no idea what coudl be wrong. Although we have a workaround that will probably eliminate this issue, it would be really nice to know what is going on.
Tags
<ios><core-data><nsmanagedobject>
Title
Corruption of NSManagedObject-derived objects when property is accessed
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1. PO
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1. USdandan78
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1. USdandan78
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