UITableView not updating
core-data, ios, objective-c, uitableview
Solution
I think your problem is the architecture of your view controllers. Try this:
1) Set up all the core data stack in the app delegate. Pass the associated managed object context to all your view controllers as a property. That is the pattern Apple uses in many of its sample code examples.
2) For each table view controller, create its own `NSFetchedResultsController`, normally also as a property. Use the Apple samples as a guide.
3) Never fetch any data from another view controller, as you do in your code. You cannot and should not get the table data for the `AudioTableViewController` from the `MusikerViewController`.
It is possible and sometimes useful to have a central data object that provides data to view controllers. You cannot have this data object be a view controller. This is a blatant (and in your case fatal) violation of the MVC design pattern. Your error most likely stems from that (because `MusikerViewController` is not on screen and may even be deallocated).
4) Make sure that in your `datasource` methods you use only the fetched results controller to populate the tables and deliver media.
Problem
I'm using a Core Data model and a UITableViewController table view. My model seems to be working quite well however my table view is not updating when I add an entity to my model. The reason I believe my model is working is because when I add an entity nothing shows up in the view during run time, however if I cut the task then start it up new, suddenly the entity I previously created shows up in the table view. Here is my table view controller - AudioTableViewController.h ``` #import <UIKit/UIKit.h> #import "Bank.h" #import "Player.h" @class Player; @interface AudioTableViewController : UITableViewController <UITableViewDelegate, UITableViewDataSource> { Player *myMainMan; } -(void)addAudioEntityToArray:(AudioFile *)event; -(NSMutableArray *)recordingsArray; @end ``` AudioTableViewController.m (implementation file) ``` #import "AudioTableViewController.h" @implementation AudioTableViewController -(void)addAudioEntityToArray:(AudioFile *)event { NSIndexPath *indexPath; if(event.type) { [[MusikerViewController recordingsArray] addObject:event];//self? indexPath = [NSIndexPath indexPathForRow:0 inSection:0]; }else { [[MusikerViewController downloadsArray] addObject:event]; indexPath = [NSIndexPath indexPathForRow:0 inSection:1]; } [[self tableView] setEditing:YES animated:NO]; [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationNone]; } - (void)viewDidLoad { [[self tableView] reloadData]; [super viewDidLoad]; self.title = @"Audio Files";//put this in application delegate self.navigationItem.leftBarButtonItem = self.editButtonItem; } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // Return the number of sections. return 2; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // Return the number of rows in the section. NSLog(@"Place I"); if(section == 0) { return [[MusikerViewController recordingsArray] count]; } else if (section == 1) { return [[MusikerViewController downloadsArray] count]; } } ``` ... more methods Here is part of my Bank class that might be relevant Bank.h ``` #import <Foundation/Foundation.h> #import <AudioToolbox/AudioToolbox.h> #import "AudioFile.h" #import "AudioTableViewController.h" #import "MusikerAppDelegate.h" @interface Bank : NSObject <UIAlertViewDelegate> { NSManagedObjectContext *managedObjectContext; AudioFile *sound; } @property (retain, nonatomic) NSManagedObjectContext *managedObjectContext; +(NSString *)getDataPath:(NSString *)fileExtDate; -(AudioFile *)addAudioFileEntityToModelWithDate:(NSDate *)theD andURLString:(NSString *)str; -(BOOL)removeAudioFromModel:(id)audio; -(NSMutableArray *)getFetchArray; @end ``` Bank.m ``` #import "Bank.h" @implementation Bank @synthesize managedObjectContext; - (AudioFile *)addAudioFileEntityToModelWithDate:(NSDate *)theD andURLString:(NSString *)str { sound = (AudioFile *)[NSEntityDescription insertNewObjectForEntityForName:@"AudioFile" inManagedObjectContext:managedObjectContext]; sound.creationDate = theD; sound.soundPath = str; //set the sound path to the sound file's url [self alertForTitle]; return sound; } - (BOOL)saveContext { NSError *error = nil; if(!managedObjectContext) { NSLog(@"managedObejctContext problem at saveContext Bank"); } if (![managedObjectContext save:&error]) { return NO; } else { return YES; } } - (NSMutableArray *)getFetchArray { NSLog(@"ManagedObjectContext at getFetchArray"); NSLog(@"Context: %@",managedObjectContext); NSFetchRequest *request = [[NSFetchRequest alloc] init]; if(!managedObjectContext) { NSLog(@"There is no managedObjectContext in getFetchArray Bank"); } NSEntityDescription *entity = [NSEntityDescription entityForName:@"AudioFile" inManagedObjectContext:managedObjectContext]; [request setEntity:entity]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"creationDate" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptors release]; [sortDescriptor release]; NSError *error = nil; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if (mutableFetchResults == nil) { NSLog(@"mutableFetchResults array is nil"); } [request release]; return mutableFetchResults; } + (NSString *)getDataPath:(NSString *)fileExtDate { NSLog(@"getDataPath called"); NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; documentsDirectory = [documentsDirectory stringByAppendingPathComponent:@"Musik Directory"]; //changing the recording directory to Musik Directory NSError *error; if (![[NSFileManager defaultManager] fileExistsAtPath:documentsDirectory]) { [[NSFileManager defaultManager] createDirectoryAtPath:documentsDirectory withIntermediateDirectories:YES attributes:nil error:&error]; NSLog(@"In the if statement"); } NSString *docPath = [documentsDirectory stringByAppendingPathComponent:fileExtDate]; return docPath; } ``` Player.h ``` #import <Foundation/Foundation.h> #import <AVFoundation/AVFoundation.h> #import "Bank.h" @class Bank; @interface Player : NSObject <AVAudioPlayerDelegate, AVAudioRecorderDelegate> { Bank *daBank; AVAudioPlayer *musicPlayer; AVAudioRecorder *musicRecorder; NSDate *myDate; NSString *strPath; NSString *documentPath_; NSMutableArray *arrayListOfRecordSound; } -(void)playSoundFile:(NSString *)soundFilePath; -(BOOL)saveRecordingWithDate:(NSDate *)theD andURLString:(NSString *)str; -(void)recordSomething; -(void)playRecording; -(void)play; + (NSString *)dateString:(NSDate *)date; + (NSString *)dateString; @end ``` Player.m ``` - (Bank *)daBank { if(!daBank) { daBank = [[Bank alloc] init]; } return daBank; } -(BOOL)saveRecording { //this is the method that adds the new object to both the //model and view, the method that calls this method is not shown Bank *B = [MusikerViewController daBank]; AudioTableViewController *ATVC2 = [MusikerViewController ATVControl]; AudioFile *myAudioFileMusicX314 = [[B addAudioFileEntityToModelWithDate:myDate andURLString:strPath] retain]; myAudioFileMusicX314.type = true; [ATVC2 addAudioEntityToArray:myAudioFileMusicX314]; if(![B saveContext]) { NSLog(@"addAudioFileEntityToModel is returning a nil managedObjectContext"); return NO; } [myDate release]; [strPath release]; [myAudioFileMusicX314 release]; [ATVC2 release]; return YES; } ``` Last but not least, MusikViewController.h ``` #import <UIKit/UIKit.h> #import "Player.h" #import "Bank.h" #import <QuartzCore/QuartzCore.h> #import "MyButtonView.h" #import "AudioTableViewController.h" @class AudioTableViewController; @class Bank; @class Player; @interface MusikerViewController : UIViewController { ] BOOL *pressed; } Player *myMainMan; Bank *daBank; AudioTableViewController *ATVControl; NSMutableArray *recordingsArray; NSMutableArray *downloadsArray; + (Bank *)daBank; + (Player *)myMainMan; + (AudioTableViewController *)ATVControl; + (NSMutableArray *)recordingsArray; + (NSMutableArray *)downloadsArray; @end ``` MusikViewController.m ``` + (NSMutableArray *)recordingsArray { NSLog(@"recordingsArray called"); if(!recordingsArray) { recordingsArray = [[NSMutableArray alloc] init]; NSMutableArray *bigTempArray = [[[[Bank alloc] init] autorelease] getFetchArray]; //change this for(AudioFile *af in bigTempArray) if(af.type) { [recordingsArray addObject:af]; } NSLog(@"recordingsArray exists"); } return recordingsArray; } + (NSMutableArray *)downloadsArray { NSLog(@"recordingsArray called"); if(!downloadsArray) { downloadsArray = [[NSMutableArray alloc] init]; // if(!bigTempArray) NSMutableArray *bigTempArray = [[[[Bank alloc] init] autorelease] getFetchArray]; for(AudioFile *af in bigTempArray) if(!af.type) { [downloadsArray addObject:af]; } } return downloadsArray; } ``` If there are any more methods that might be relevant, let me know and I will happily post them. I should also mention that, I can add a single entity to the array after I launch the app, but after that its the same problem.