[_PFArray MR_deleteInContext:]: unrecognized selector sent to instance - ios

Question

I am using MagicalRecord (MR) to delete all records belonging to a selected client (I successfully delete the client record, then go after the appointment records for that client). In doing so, I am getting the error.
[_PFArray MR_deleteInContext:]: unrecognized selector sent to instance
Here is the code, along with the pertinent definitions:
// set up predicate using selectedClientKey
NSManagedObjectContext *localContext = [NSManagedObjectContext MR_contextForCurrentThread];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"aClientKey == %#", selectedClientKey];
ClientInfo *clientSelected = [ClientInfo MR_findFirstWithPredicate:predicate inContext:localContext];
if(clientSelected) {
[clientSelected MR_deleteInContext:localContext];
[localContext MR_saveToPersistentStoreAndWait];
}
// delete clients appointments...
predicate = [NSPredicate predicateWithFormat:#"aApptKey == %#", selectedClientKey]; // use client key
AppointmentInfo *apptSelected = [AppointmentInfo MR_findAllWithPredicate:predicate inContext:localContext];
if(apptSelected) {
[apptSelected MR_deleteInContext:localContext];
[localContext MR_saveToPersistentStoreAndWait];
}
Here is the definition of AppointmentInfo:
#interface AppointmentInfo : NSManagedObject
#property (nonatomic, retain) NSString * aApptKey;
#property (nonatomic, retain) NSDate * aEndTime;
#property (nonatomic, retain) NSString * aServiceTech;
#property (nonatomic, retain) NSDate * aStartTime;
On the findAllWithPredicate statement, I am getting this compiler warning:
CalendarViewController.m:80:43: Incompatible pointer types assigning
to 'NSMutableArray *' from 'NSArray *__strong'
I understand that the findAllWithPredicate statement will return a NSArray; however I have seen examples using NSManagedObject, which is what AppointmentInfo is. ClientInfo in the 3rd line down is also a NSManagedObject and it has NO compiler warning. I thought that it might be because there was only one (1) record returned from the find statement, but it makes no difference, one record or multiple records.
Am I getting the run error due to the compiler warning, or is there something else wrong? (I have looked at Google and SO, and found nothing that addresses this particular issue).

Answer 1

You are correct that findAllWithPredicate: will return an array. The examples you've seen are most likely using the findFirstWithPredicate: or similar style method. Find First, as the name implies, will return the first object in the results returned from the request. This is most likely what you want as well.

Answer 2

I figured it out... for those who might have the same issue, MR_findAll returns a NSArray which you have to "walk through" and delete each individually. Here's the corrected code from above:
// delete clients appointments...
predicate = [NSPredicate predicateWithFormat:#"aApptKey == %#", selectedClientKey]; // use client key
NSArray *apptDataArray = [AppointmentInfo MR_findAllWithPredicate:predicate inContext:localContext];
for(int i = 0; i < apptDataArray.count; i++) {
AppointmentInfo *ai = [apptDataArray objectAtIndex: i];
[ai MR_deleteEntity];
}
[localContext MR_saveToPersistentStoreAndWait];