Sort button for tableview in navigation app - iphone

I'm currently creating an application to rank teams based on different criteria, and I would like to give users the option to sort the teams in a table view based on those different criteria. I use core data in my app to store my teams, and am using a navigation-based template that starts by showing the user a table view with the option to click on each cell to edit a team. An example of what I want to do is how the Errands app lets you sort your tasks by Due date, priority, alphabetical, and manual.
I tried creating buttons that called a method to change, the sortDescriptor key, but I have to recreated the fetchedResultsController every time for this to update (i.e. don't check if the fetchedResultsController_ ! = nil), and that seems to copy the cell that is changing positions into the new position rather than moving it there.
How should I go about coding a sort button that lets the user change the criteria by which the table is sorted and correctly update the table? I've read a lot of posts concerning the fetchResultsController and NSSortDescriptors, but the solutions seem to be a one-time deal.
I could really use some help, or reference to a tutorial that shows how to do this.
Here is my RootViewController.m:
#import "RootViewController.h"
#import "TeamViewController.h"
#interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
#end
#implementation RootViewController
#synthesize fetchedResultsController=fetchedResultsController_;
#synthesize managedObjectContext=managedObjectContext_;
#synthesize sortParam;
//#synthesize sortDescriptors;
#pragma mark -
#pragma mark View lifecycle
- (void)viewDidLoad {
NSLog(#"viewDidLoad called");
sortParam = #"totalRank";
[super viewDidLoad];
self.title = #"Title";
// Set up the edit and add buttons.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(showTeamView)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
UIBarButtonItem* button1 = [[[UIBarButtonItem alloc] initWithTitle:#"Rank" style:UIBarButtonItemStyleBordered target:self action:#selector(reSort1:)] autorelease];
UIBarButtonItem* button2 = [[[UIBarButtonItem alloc] initWithTitle:#"Name" style:UIBarButtonItemStyleBordered target:self action:#selector(reSort2:)] autorelease];
[self setToolbarItems:[NSArray arrayWithObjects:button1, button2, nil]];
}
-(void)showTeamView {
NSLog(#"showTeamView called");
TeamViewController *teamViewController = [[TeamViewController alloc] initWithRootController:self team:nil];
[self presentModalViewController:teamViewController animated:YES];
[teamViewController release];
}
// Implement viewWillAppear: to do additional setup before the view is presented.
- (void)viewWillAppear:(BOOL)animated {
NSLog(#"viewWillAppear called");
// sortParam = #"totalRank";
[super viewWillAppear:animated];
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
NSLog(#"configureCell:atIndexPath called");
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *textLabelText = [NSString stringWithFormat:#"%# - %#", [[managedObject valueForKey:#"teamName"]description], [[managedObject valueForKey:#"teamNumber"]description]];
// NSLog(textLabelText);
cell.textLabel.text = textLabelText;//[[managedObject valueForKey:#"teamName"] description];
cell.detailTextLabel.text = [[managedObject valueForKey:#"totalRank"] description];
// cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
}
- (void)reSort1:(id)sender {
NSLog(#"reSort1 called by: %#", sender);
sortParam = #"totalRank";
[self.tableView reloadData];
[self viewDidLoad];
}
- (void)reSort2:(id)sender {
NSLog(#"resort2 called by %#", sender);
sortParam = #"teamName";
[self.tableView reloadData];
[self viewDidLoad];
}
#pragma mark -
#pragma mark Add a new object
-(void)insertTeamWithName:(NSString *)teamName teamNumber:(NSString *)teamNumber noteField:(NSString *)noteField driveTrain:(NSString *)driveTrain autoRank:(NSNumber *)autoRank offenseRank:(NSNumber *)offenseRank defenseRank:(NSNumber *)defenseRank speedRank:(NSNumber *)speedRank shooterRank:(NSNumber *)shooterRank totalRank:(NSNumber *)totalRank{
// Create a new instance of the entity
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
// Configure the team
[newManagedObject setValue:teamName forKey:#"teamName"];
[newManagedObject setValue:teamNumber forKey:#"teamNumber"]; //new
[newManagedObject setValue:noteField forKey:#"noteField"];
[newManagedObject setValue:autoRank forKey:#"autoRank"];
[newManagedObject setValue:driveTrain forKey:#"driveTrain"];
[newManagedObject setValue:offenseRank forKey:#"offenseRank"];
[newManagedObject setValue:defenseRank forKey:#"defenseRank"];
[newManagedObject setValue:speedRank forKey:#"speedRank"];
[newManagedObject setValue:shooterRank forKey:#"shooterRank"];
/* [newManagedObject setValue:armRank forKey:#"armRank"];
[newManagedObject setValue:speedRank forKey:#"speedRank"]; */
[newManagedObject setValue:totalRank forKey:#"totalRank"];
[self saveContext];
NSLog(#"insertTeamWithNameCalled");
}
- (void)saveContext {
// Create a new instance of the entity managed by the fetched results controller.
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
// Save the context.
NSError *error = nil;
if (![context save:&error]) {
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error in saveContext %#, %#", error, [error userInfo]);
// abort();
}
}
- (void)setEditing:(BOOL)editing animated:(BOOL)animated {
// Prevent new objects being added when in editing mode.
[super setEditing:(BOOL)editing animated:(BOOL)animated];
self.navigationItem.rightBarButtonItem.enabled = !editing;
}
#pragma mark -
#pragma mark Table view data source
/*
- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath {
}
*/
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"tableView:cellForRowAtIndexPath called");
static NSString *CellIdentifier = #"TableCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
// Return NO if you do not want the specified item to be editable.
return YES;
}
*/
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
// Save the context.
[self saveContext];
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// The table view should not be re-orderable.
return NO;
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSManagedObject *team = [[self fetchedResultsController] objectAtIndexPath:indexPath];
TeamViewController *teamViewController = [[TeamViewController alloc] initWithRootController:self team:team];
[self presentModalViewController:teamViewController animated:YES];
[teamViewController release];
}
#pragma mark -
#pragma mark Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController {
NSLog(#"fetchResultsController called");
/*
if (fetchedResultsController_ != nil) {
return fetchedResultsController_;
}
*/
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Team" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:sortParam ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
NSLog(#"sortParam == %#", sortParam);
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:#"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![fetchedResultsController_ performFetch:&error]) {
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error in fetchedResultsController %#, %#", error, [error userInfo]);
// abort();
}
return fetchedResultsController_;
}
#pragma mark -
#pragma mark Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
NSLog(#"controllerWillChangeContent called");
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
NSLog(#"controller:didChangeObject called");
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
NSLog(#"controllerDidChangeContent called");
[self.tableView endUpdates];
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// In the simplest, most efficient, case, reload the table view.
[self.tableView reloadData];
}
*/
#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
}
- (void)dealloc {
[fetchedResultsController_ release];
[managedObjectContext_ release];
// [sortParam release];
[super dealloc];
}
#end

Related

What Does This NSZombie Error Message Mean?

I turned zombies on because I was getting some crashes. Now I' getting this error in console. Does anyone know what it means?
*** -[RoutineDayTableViewController retain]: message sent to deallocated instance 0x7464150
#implementation RoutineDayTableViewController
#synthesize fetchedResultsController;
#synthesize exerciseChooserView;
#synthesize routineTableView;
#synthesize managedObjectContext;
#synthesize selectedExercise;
#synthesize theSelectedRoutine;
- (void)dealloc
{
NSLog(#"dealloc");
[fetchedResultsController release];
[selectedExercise release];
[managedObjectContext release];
[exerciseChooserView release];
[routineTableView release];
[theSelectedRoutine release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
self.routineTableView.delegate = self;
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
}
- (void)viewDidUnload
{
NSLog(#"viewDidUnload");
[super viewDidUnload];
self.exerciseChooserView = nil;
self.routineTableView = nil;
self.fetchedResultsController = nil;
}
#pragma mark - Exercise Editing
-(IBAction)exerciseChooser
{
RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
[self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}
-(void)addExercise
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
NSError *error = nil;
Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:#"Exercise" inManagedObjectContext:managedObjectContext];
exercise.name = self.selectedExercise;
NSLog(#"addExercise theSelectedRoutine: %#", theSelectedRoutine);
[self.theSelectedRoutine addRoutineToExercisesObject:exercise];
if (![fetchedResultsController.managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(#"%#", error);
NSLog(#"addExercise theSelectedRoutine: %#", theSelectedRoutine);
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = tempExercise.name;
return cell;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSLog(#"fetched results : \n%#\n",[self.fetchedResultsController fetchedObjects]);
// Commit the change.
NSError *error = nil;
// Update the array and table view.
if (![fetchedResultsController.managedObjectContext save:&error])
{
// Handle the error.
}
//[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:#"name"] description];
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
[routineTableView deselectRowAtIndexPath:indexPath animated:YES];
DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:#"DetailViewController" bundle:nil];
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil)
{
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Exercise" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSLog(#"fetchedResultsController theSelectedRoutine: %#",theSelectedRoutine);
[fetchRequest setPredicate:[NSPredicate predicateWithFormat: #"ANY exerciseToRoutine == %#", theSelectedRoutine]];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error])
{
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
return fetchedResultsController;
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.routineTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.routineTableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView endUpdates];
}
#end
Update, this method is in another viewController. Could this be causing the problem?
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
NSString *selectedRow = [[self.exerciseArray objectAtIndex:indexPath.row]objectForKey:#"exerciseName"];
NSLog(#"Row Selected: %#", selectedRow);
RoutineDayTableViewController *routineDayTableViewController=[self.navigationController.viewControllers objectAtIndex:([self.navigationController.viewControllers count] -3)];
routineDayTableViewController.selectedExercise = selectedRow;
[routineDayTableViewController addExercise];
[routineDayTableViewController release];
[self dismissView];
}
and here is another method in yet another viewController that access this class:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
RoutineDayTableViewController *detailViewController = [[RoutineDayTableViewController alloc] initWithNibName:#"RoutineDayTableViewController" bundle:nil];
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
detailViewController.title = [[managedObject valueForKey:#"name"] description];
detailViewController.theSelectedRoutine = [__fetchedResultsController objectAtIndexPath: indexPath];
NSLog(#"detailViewController.theSelectedRoutine:%#",detailViewController.theSelectedRoutine);
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
The error message means that you are sending a message to an object whose retain count went to zero and was subsequently deallocated. Based on your code snippet, I think your problem is this code -
RoutineDayTableViewController *routineDayTableViewController=[self.navigationController.viewControllers objectAtIndex:([self.navigationController.viewControllers count] -3)];
routineDayTableViewController.selectedExercise = selectedRow;
[routineDayTableViewController addExercise];
[routineDayTableViewController release];
The release call here looks suspicious. You are releasing something you haven't alloced here.
Have you run static analyzer on your code? It is helpful in detecting bugs of this kind.
The instance of the class RoutineDayTableViewController is the problem, so it's not likely in the code you posted here.
Check the code where you use this class.
It may help you to build using the Analyse option, this often detects the problem.
There are some place where the instance of RoutineDayTableViewController class is release and after that you are trying to access it.
If you want to check , Please don't release that object and try to run.

Convert From FetchRequest Array To NSFetchedResultsController

My app currently fetches data on routineViewController's launch and loads it into eventsArray. I was encouraged to try using a NSFetchedResultsController instead.
I'm currently going through the Apple docs to learn more about it but in the meantime if anyone could help me start this conversion process, that would be great.
I added all the fetchresultscontroller code from the apple template but need help combing my addEvent method and the fetchresultcontroller's insertnewobject method. Or do I keep both?
#implementation RoutineTableViewController
#synthesize routineTableView;
#synthesize eventsArray;
#synthesize entered;
#synthesize managedObjectContext;
#pragma mark - View lifecycle
- (void)viewDidLoad
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
}
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Routine" inManagedObjectContext:managedObjectContext];
[request setEntity:entity];
NSError *error = nil;
NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
if (mutableFetchResults == nil) {
// Handle the error.
}
[self setEventsArray:mutableFetchResults];
[mutableFetchResults release];
[request release];
UIBarButtonItem * addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(showPrompt)];
[self.navigationItem setLeftBarButtonItem:addButton];
[addButton release];
UIBarButtonItem *editButton = [[UIBarButtonItem alloc]initWithTitle:#"Edit" style:UIBarButtonItemStyleBordered target:self action:#selector(toggleEdit)];
self.navigationItem.rightBarButtonItem = editButton;
[editButton release];
[super viewDidLoad];
}
- (void)viewDidUnload
{
self.eventsArray = nil;
[super viewDidUnload];
}
-(void)toggleEdit
{
[self.routineTableView setEditing: !self.routineTableView.editing animated:YES];
if (self.routineTableView.editing)
[self.navigationItem.rightBarButtonItem setTitle:#"Done"];
else
[self.navigationItem.rightBarButtonItem setTitle:#"Edit"];
}
- (void)dealloc
{
[managedObjectContext release];
[eventsArray release];
[entered release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark -
#pragma mark Add an event
-(void)addEvent
{
Routine *routine = (Routine *)[NSEntityDescription insertNewObjectForEntityForName:#"Routine" inManagedObjectContext:managedObjectContext];
routine.name=entered;
NSError *error = nil;
if (![managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(#"%#", error);
[eventsArray addObject:routine];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.routineTableView reloadData];
NSInteger lastSection = [self.routineTableView numberOfSections] -1;
[self.routineTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.routineTableView numberOfRowsInSection:lastSection]-1 inSection:lastSection] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
-(void)showPrompt
{
AlertPrompt *prompt = [AlertPrompt alloc];
prompt = [prompt initWithTitle:#"Add Workout Day" message:#"\n \n Please enter title for workout day" delegate:self cancelButtonTitle:#"Cancel" okButtonTitle:#"Add"];
[prompt show];
[prompt release];
}
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
if (buttonIndex != [alertView cancelButtonIndex])
{
entered = [(AlertPrompt *)alertView enteredText];
if(eventsArray && entered)
{
[self addEvent];
}
}
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [eventsArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
Routine *tempRoutine = (Routine *)[eventsArray objectAtIndex:indexPath.row];
cell.textLabel.text = tempRoutine.name;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object at the given index path.
NSManagedObject *eventToDelete = [eventsArray objectAtIndex:indexPath.row];
[managedObjectContext deleteObject:eventToDelete];
// Update the array and table view.
[eventsArray removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
// Commit the change.
NSError *error = nil;
if (![managedObjectContext save:&error]) {
// Handle the error.
}
}
}
EDIT Added methods for adding events/objects
-(void)addEvent
{
Routine *routine = (Routine *)[NSEntityDescription insertNewObjectForEntityForName:#"Routine" inManagedObjectContext:managedObjectContext];
routine.name=entered;
NSError *error = nil;
if (![managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(#"%#", error);
[eventsArray addObject:routine];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.routineTableView reloadData];
NSInteger lastSection = [self.routineTableView numberOfSections] -1;
[self.routineTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.routineTableView numberOfRowsInSection:lastSection]-1 inSection:lastSection] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
And the fetchResultsController's method:
- (void)insertNewObject
{
// Create a new instance of the entity managed by the fetched results controller.
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
[newManagedObject setValue:[NSDate date] forKey:#"timeStamp"];
// Save the context.
NSError *error = nil;
if (![context save:&error])
{
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
Update With Full Code
#implementation RoutineTableViewController
#synthesize routineTableView;
#synthesize eventsArray;
#synthesize entered;
#synthesize managedObjectContext;
#synthesize fetchedResultsController=__fetchedResultsController;
#pragma mark - View lifecycle
- (void)viewDidLoad
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
}
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Routine" inManagedObjectContext:managedObjectContext];
[request setEntity:entity];
NSError *error = nil;
NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
if (mutableFetchResults == nil) {
// Handle the error.
}
[self setEventsArray:mutableFetchResults];
[mutableFetchResults release];
[request release];
UIBarButtonItem * addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(showPrompt)];
[self.navigationItem setLeftBarButtonItem:addButton];
[addButton release];
UIBarButtonItem *editButton = [[UIBarButtonItem alloc]initWithTitle:#"Edit" style:UIBarButtonItemStyleBordered target:self action:#selector(toggleEdit)];
self.navigationItem.rightBarButtonItem = editButton;
[editButton release];
[super viewDidLoad];
}
- (void)viewDidUnload
{
self.eventsArray = nil;
[super viewDidUnload];
}
-(void)toggleEdit
{
[self.routineTableView setEditing: !self.routineTableView.editing animated:YES];
if (self.routineTableView.editing)
[self.navigationItem.rightBarButtonItem setTitle:#"Done"];
else
[self.navigationItem.rightBarButtonItem setTitle:#"Edit"];
}
- (void)dealloc
{
[__fetchedResultsController release];
[managedObjectContext release];
[eventsArray release];
[entered release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark -
#pragma mark Add an event
-(void)addEvent
{
Routine *routine = (Routine *)[NSEntityDescription insertNewObjectForEntityForName:#"Routine" inManagedObjectContext:managedObjectContext];
routine.name=entered;
NSError *error = nil;
if (![managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(#"%#", error);
[eventsArray addObject:routine];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
//[self.routineTableView reloadData];
NSInteger lastSection = [self.routineTableView numberOfSections] -1;
[self.routineTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.routineTableView numberOfRowsInSection:lastSection]-1 inSection:lastSection] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
/*
- (void)insertNewObject
{
// Create a new instance of the entity managed by the fetched results controller.
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
[newManagedObject setValue:[NSDate date] forKey:#"timeStamp"];
// Save the context.
NSError *error = nil;
if (![context save:&error])
{
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
/*
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
*/
-(void)showPrompt
{
AlertPrompt *prompt = [AlertPrompt alloc];
prompt = [prompt initWithTitle:#"Add Workout Day" message:#"\n \n Please enter title for workout day" delegate:self cancelButtonTitle:#"Cancel" okButtonTitle:#"Add"];
[prompt show];
[prompt release];
}
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
if (buttonIndex != [alertView cancelButtonIndex])
{
entered = [(AlertPrompt *)alertView enteredText];
if(eventsArray && entered)
{
[self addEvent];
}
}
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
Routine *tempRoutine = (Routine *)[eventsArray objectAtIndex:indexPath.row];
cell.textLabel.text = tempRoutine.name;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
// Update the array and table view.
[eventsArray removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
// Commit the change.
NSError *error = nil;
if (![managedObjectContext save:&error]) {
// Handle the error.
}
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:#"name"] description];
}
/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/
/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the item to be re-orderable.
return YES;
}
*/
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
/*
<#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:#"<#Nib name#>" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
*/
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (__fetchedResultsController != nil)
{
return __fetchedResultsController;
}
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Routine" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:#"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error])
{
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return __fetchedResultsController;
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.routineTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.routineTableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView endUpdates];
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
// In the simplest, most efficient, case, reload the table view.
[self.tableView reloadData];
}
*/
#end
Basically, all you would do would be to move your current fetch into the fetched result controllers setup method. Then you would use the fetched results controller fetchObjects property (which is an array) exactly as you currently use eventsArray.
Look at a Core Data using Navigation based project template in Xcode. It should have a tableview controller configured with a fetched results controller.

Why Can't I delete the bottom row of my UITableView?

When the user presses Edit, my UITableView adds an insert row at the top (with a green plus), and puts all the other rows into delete mode (red minus). Alternatively, the user can swipe-to-delete without pressing the edit button. I am using a couple of Ivars to keep track of whether the table is in edit mode from a swipe, or from pressing the edit button, and act accordingly (e.g. updating numberOfRowsInTableView: with the extra insert row when Edit has been pressed).
Everything works perfectly except on thing: when in Edit mode (i.e. the user has explicitly hit the edit button, and the insert row has appeared at the top), if the user tries to delete the bottom row, the next row up gets deleted instead. Deleting any other row is fine.
EDIT -- It appears to delete the row above, but if I immediately quit and reload the app, it turns out the bottom row has gone after all. So I'm guessing my UITableView is going out of sync with my NSFetchedResultsController somewhere.
Here's the code I'm using:
#import "ChecklistsViewController.h"
#import "Checklist.h"
#interface ChecklistsViewController (private)
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
- (void)addingView;
#end
#implementation ChecklistsViewController
#synthesize category, managedObjectContext, fetchedResultsController;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
editingFromSwipe = NO;
tableIsEditing = NO;
}
return self;
}
- (void)dealloc
{
[category release];
[managedObjectContext release];
[fetchedResultsController release];
[super dealloc];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
editingFromSwipe = NO;
tableIsEditing = NO;
self.navigationItem.rightBarButtonItem = self.editButtonItem;
self.tableView.allowsSelectionDuringEditing = YES;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
int rows = [sectionInfo numberOfObjects];
if (self.editing) {
if (!editingFromSwipe && tableIsEditing) {
return rows +1;
}
return rows;
}
tableIsEditing = NO;
return rows;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
NSLog(#"Should go into if statement here! \n");
if (tableView.editing) { //
if ((indexPath.row == 0) && (!editingFromSwipe)) {
NSLog(#"Configuring Add Button Cell while editing \n");
cell.textLabel.text = #"Add New Checklist";
cell.detailTextLabel.text = nil;
}
else {
NSLog(#"Configuring other cells while editing \n");
[self configureCell:cell atIndexPath:indexPath];
}
}
else {
NSLog(#"Configuring Cell Normally While Not Editing \n");
[self configureCell:cell atIndexPath:indexPath];
}
return cell;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
int numberOfRows = [self tableView:tableView numberOfRowsInSection:indexPath.section];
int rowBeingDeleted = indexPath.row +1;
if (tableIsEditing && !editingFromSwipe && numberOfRows == rowBeingDeleted) {
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:[NSIndexPath indexPathForRow:indexPath.row-1 inSection:indexPath.section]]];
}
else {
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
}
// Save the context.
NSError *error = nil;
if (![context save:&error])
{
// TO DO: Fix error code.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
[self addingView];
}
}
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
int row = indexPath.row;
if (self.editing && row == 0) {
if (!editingFromSwipe && tableIsEditing) {
return UITableViewCellEditingStyleInsert;
}
else if (editingFromSwipe) {
return UITableViewCellEditingStyleDelete;
}
}
return UITableViewCellEditingStyleDelete;
}
- (void)tableView:(UITableView *)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
editingFromSwipe = YES;
[super tableView:tableView willBeginEditingRowAtIndexPath:indexPath];
}
- (void)tableView:(UITableView *)tableView didEndEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
[super tableView:tableView didEndEditingRowAtIndexPath:indexPath];
editingFromSwipe = NO;
}
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing:editing animated:animated];
NSArray *addRow = [NSArray arrayWithObjects:[NSIndexPath indexPathForRow:0 inSection:0], nil];
[self.tableView beginUpdates];
if (!editingFromSwipe) {
if (editing) {
tableIsEditing = YES;
[self.tableView insertRowsAtIndexPaths:addRow withRowAnimation:UITableViewRowAnimationLeft];
}
else {
[self.tableView deleteRowsAtIndexPaths:addRow withRowAnimation:UITableViewRowAnimationLeft];
}
}
[self.tableView endUpdates];
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.row != 0) {
TO DO: Code for when row is selected
}
}
#pragma mark - Data
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
Checklist *aChecklist = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = aChecklist.name;
cell.detailTextLabel.text = aChecklist.category.name;
}
- (void) addingView// :(id)sender
{
AddingViewController *viewController = [[AddingViewController alloc] initWithNibName:#"AddingViewController" bundle:nil];
viewController.delegate = self;
viewController.title = #"Add Checklist";
// Create the navigation controller and present it modally
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
[self presentModalViewController:navigationController animated:YES];
viewController.textLabel.text = #"Enter new checklist name";
[navigationController release];
[viewController release];
}
#pragma mark - AddingViewDelegate
- (void)addingViewController:(AddingViewController *)addingViewController didAdd:(NSString *)itemAdded
{
if (itemAdded != nil) {
// Turn off editing mode.
if (self.editing) [self.navigationController setEditing:NO animated:NO];
// Add the category name to our model and table view.
// Create a new instance of the entity managed by the fetched results controller.
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
Checklist *newChecklist = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
[category addChecklistsObject:newChecklist];
newChecklist.name = itemAdded;
// [newChecklist setDateStamp:[NSDate date]];
// Save the context.
NSError *error = nil;
if (![context save:&error])
{
TO DO: fix error code.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
[self dismissModalViewControllerAnimated:YES];
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil)
{
return fetchedResultsController;
}
// Set up the fetched results controller.
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Checklist" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set 4* the predicate so we only see checklists for this category.
NSPredicate *requestPredicate = [NSPredicate predicateWithFormat:#"category.name = %#", self.category.name];
[fetchRequest setPredicate:requestPredicate];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:self.managedObjectContext
sectionNameKeyPath:nil
cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error])
{
// TO DO: error stuff
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return fetchedResultsController;
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView endUpdates];
}
#end
You can add static cells to UITableViews that get their data from a NSFetchedResultsController. But to do this you have to adjust almost all NSIndexPaths that are used within one of the UITableViewDelegate, UITableViewDataSource or NSFetchedResultsControllerDelegate methods.
I added some helper methods that translate the indexpath of the tableview to the indexpath of the fetched resultscontroller and the other way around. Something like this could be used if you want to add a row on top:
- (NSIndexPath *)tableIndexPathFromNSFRCIndexPath:(NSIndexPath *)ip {
if (editingMode && ip.section == 0) {
NSIndexPath *newIP = [NSIndexPath indexPathForRow:ip.row+1 inSection:ip.section];
return newIP;
}
return ip;
}
- (NSIndexPath *)nsfrcIndexPathFromTableIndexPath:(NSIndexPath *)ip {
if (editingMode && ip.section == 0) {
NSIndexPath *newIP = [NSIndexPath indexPathForRow:ip.row-1 inSection:ip.section];
return newIP;
}
return ip;
}
and then you have to change every method that passes an indexpath from the table to the fetchedresultscontroller or from the frc to the table. I show you two as an example.
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
newIndexPath = [self tableIndexPathFromNSFRCIndexPath:newIndexPath];
indexPath = [self tableIndexPathFromNSFRCIndexPath:indexPath];
switch(type) {
case NSFetchedResultsChangeInsert:
[self.listTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.listTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[self.listTableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[self.listTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.listTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[aTableView deselectRowAtIndexPath:indexPath animated:YES];
if (editingMode && indexPath.section == 0 && indexPath.row == 0) {
// Add New entry...
}
else {
indexPath = [self nsfrcIndexPathFromTableIndexPath:indexPath];
NSManagedObject *selectedObject = [self.fetchedResultsController objectAtIndexPath:indexPath]);
}
}
Your design it at fault. You shouldn't be adding rows anywhere but where they logically go in the table.
The entire point of a fetched results controller (FRC) is to synchronize the tableview with the data. The order of the rows in the table should reflect the order of managed objects in the fetchedObjects array. By inserting a row at the bottom or top and while adding an object that does not necessarily logically belong at the top or bottom of the table, are breaking that synchronization.
When you add a new managed object in addingViewController:didAdd: the FRC alerts it delegate which tries to redraw the table. You've tried to compensate for this but you really can't. All you indexes are coming off.
Instead of using a row to input new rows. Use a tableview header or footer view. That way, you can freeze the tableview, create the new object, then update the table and the new object will show up where it logical belongs in the table.
To not get the rows mixed up I would suggest putting the insert row in its own section. Since you're obviously just using one section you know that the section you send to FRC should always be 0. The code would be as simple as:
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:[NSIndexPath indexPathForRow:indexPath.row inSection:0]]];
TechZen's solution will also work, so which solution you choose is entirely about what design you prefer. TechZen's solution doesn't interfere with having multiple sections, but this solution could be modified to support multiple sections as well.

Swipe-To-Delete triggers the insert row on my table

In my app, the user is presented with a table of data. When they click "edit", an edit row appears at the top with a green plus-sign - they can use this to add another item to the list.
This works fine when the user just taps the edit button, but if the users uses swipe-to-delete, the edit row appears (without the green plus) and everything goes weird (delete button appearing on the wrong row, etc).
Can anyone tell me what I'm doing wrong? Sorry just to dump a load of code but I've gone round in so many circles that I've lost all perspective!
#import "ChecklistsViewController.h"
#import "Checklist.h"
#interface ChecklistsViewController (private)
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
- (void)addingView;
#end
#implementation ChecklistsViewController
#synthesize category, managedObjectContext, fetchedResultsController;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
editControlsDidShow = NO;
}
return self;
}
- (void)dealloc
{
[category release];
[managedObjectContext release];
[fetchedResultsController release];
[super dealloc];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationItem.rightBarButtonItem = self.editButtonItem;
self.tableView.allowsSelectionDuringEditing = YES;
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
if (tableView.editing) return [sectionInfo numberOfObjects] +1;
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
[self configureCell:cell atIndexPath:indexPath];
if (tableView.editing) {
if (indexPath.row == 0) {
cell.textLabel.text = #"Add New Checklist";
cell.detailTextLabel.text = nil;
}
if (indexPath.row != 0) {
[self configureCell:cell atIndexPath:indexPath];
}
}
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSError *error = nil;
if (![context save:&error])
{
// error code
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
[self addingView];
}
}
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
int row = indexPath.row;
if (self.editing && row == 0) {
if (editControlsDidShow) return UITableViewCellEditingStyleInsert;
return UITableViewCellEditingStyleDelete;
}
return UITableViewCellEditingStyleDelete;
}
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
editControlsDidShow = NO;
[super setEditing:editing animated:animated];
NSArray *addRow = [NSArray arrayWithObjects:[NSIndexPath indexPathForRow:0 inSection:0], nil];
[self.tableView beginUpdates];
if (editing) {
editControlsDidShow = YES;
[self.tableView insertRowsAtIndexPaths:addRow withRowAnimation:UITableViewRowAnimationLeft];
}
else {
[self.tableView deleteRowsAtIndexPaths:addRow withRowAnimation:UITableViewRowAnimationLeft];
}
[self.tableView endUpdates];
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// not done yet
}
#pragma mark - Data
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
Checklist *aChecklist = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [aChecklist.name description];
cell.detailTextLabel.text = [aChecklist.category.name description];
}
- (void) addingView// :(id)sender
{
//Create the root view controller for the navigation controller
AddingViewController *viewController = [[AddingViewController alloc] initWithNibName:#"AddingViewController" bundle:nil];
viewController.delegate = self;
viewController.title = #"Add Checklist";
// Create the navigation controller and present it modally
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
[self presentModalViewController:navigationController animated:YES];
viewController.textLabel.text = #"Enter new checklist name";
[navigationController release];
[viewController release];
}
#pragma mark - AddingViewDelegate
- (void)addingViewController:(AddingViewController *)addingViewController didAdd:(NSString *)itemAdded
{
if (itemAdded != nil) {
// Turn off editing mode.
if (self.editing) [self.navigationController setEditing:NO animated:NO];
// Create a new instance of the entity managed by the fetched results controller.
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
Checklist *newChecklist = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
[category addChecklistsObject:newChecklist];
newChecklist.name = itemAdded;
NSError *error = nil;
if (![context save:&error])
{
// error code
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
[self dismissModalViewControllerAnimated:YES];
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil)
{
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Checklist" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set 4* the predicate so we only see checklists for this category.
NSPredicate *requestPredicate = [NSPredicate predicateWithFormat:#"category.name = %#", self.category.name];
[fetchRequest setPredicate:requestPredicate];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:self.managedObjectContext
sectionNameKeyPath:nil
cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error])
{
// handle the error properly!
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return fetchedResultsController;
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView endUpdates];
}
#end
I found one thing that you probably want to change:
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
I don't think you want the edit row to be editable. Here's code to fix that:
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return (indexPath.row != 0);
}
You might want an if else to make it more readable, but if you're lazy this will suffice.
Also could you point out where you add the green plus-sign? I'll update my answer when you do.
EDIT: The problem is that when you use swipe-to-delete only the row you swipe enters edit mode. The edit row doesn't enter edit mode and therefore the green plus-sign isn't shown. If the delete button is appearing on the wrong row, I would assume that the problem is that when the table view enters edit mode the edit row is added, which updates the indexPaths of all consecutive rows.
As of right now I cannot provide any code for how to solve the problem, but I can provide you with an idea. You shouldn't add the edit row when the user uses swipe-to-delete. If you can identify when swipe-to-delete is used and not add the edit row based on that your problem should be solved. I've never had a similar problem, so I've never had to do this. Thus I can't provide the details on how to do this.
If you need more/better advise or help with the implementation, let me know.
I've had the same problem and I just fixed it with this trick:
You can check how editing mode was set to YES in this vein:
- (void)tableView:(UITableView *)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
editingFromSwipe = YES;
[super tableView:tableView willBeginEditingRowAtIndexPath:indexPath];
}
- (void)tableView:(UITableView *)tableView didEndEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
[super tableView:tableView didEndEditingRowAtIndexPath:indexPath];
editingFromSwipe = NO;
}
And I guess that you already know how you proceed from this point, you create an if-function inserting the add-row-row only when editingFromSwipe is zero.
I think that we all agree that Apple is not very cooperative here. I hope it helps!

How to display data stored in core data in a table view?

I have developed a core data model for my application. I need to display the saved data into a table view. For my app I have selected split view controller. I am writing down my codes below. Please help me in this regard and write me the code that needs to be added. This is very important as my continuation in my company depends on this.
#import "RootViewController.h"
#import "DetailViewController.h"
#import "AddViewController.h"
#import "EmployeeDetailsAppDelegate.h"
/*
This template does not ensure user interface consistency during editing operations in the table view. You must implement appropriate methods to provide the user experience you require.
*/
#interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
#end
#implementation RootViewController
#synthesize detailViewController, fetchedResultsController, managedObjectContext, results, empName;
#pragma mark -
#pragma mark View lifecycle
- (void)viewDidLoad {
results = [[NSMutableDictionary alloc]init];
[results setObject:empName.text forKey:#"EmployeeName"];
[self.tableView reloadData];
[super viewDidLoad];
}
/*
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
}
*/
/*
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
}
*/
/*
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
}
*/
/*
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
}
*/
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Ensure that the view controller supports rotation and that the split view can therefore show in both portrait and landscape.
return YES;
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:#"EmployeeName"] description];
}
#pragma mark -
#pragma mark Add a new object
- (void)insertNewObject:(id)sender {
AddViewController *add = [[AddViewController alloc]initWithNibName:#"AddViewController" bundle:nil];
self.modalPresentationStyle = UIModalPresentationFormSheet;
add.wantsFullScreenLayout = NO;
[self presentModalViewController:add animated:YES];
[add release];
}
#pragma mark -
#pragma mark Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:#"EmployeeName"] description];
return cell;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object.
NSManagedObject *objectToDelete = [self.fetchedResultsController objectAtIndexPath:indexPath];
if (self.detailViewController.detailItem == objectToDelete) {
self.detailViewController.detailItem = nil;
}
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:objectToDelete];
NSError *error;
if (![context save:&error]) {
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// The table view should not be re-orderable.
return NO;
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Set the detail item in the detail view controller.
NSManagedObject *selectedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
self.detailViewController.detailItem = selectedObject;
}
#pragma mark -
#pragma mark Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController {
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Details" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"EmployeeName" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:#"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
return fetchedResultsController;
}
#pragma mark -
#pragma mark Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
[self.tableView endUpdates];
}
#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc. that aren't in use.
}
- (void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
}
- (void)dealloc {
[detailViewController release];
[fetchedResultsController release];
[managedObjectContext release];
[super dealloc];
}
#end
//
// AddViewController.m
// EmployeeDetails
//
// Created by Dipanjan on 15/02/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import "AddViewController.h"
#import "EmployeeDetailsAppDelegate.h"
#import "RootViewController.h"
#implementation AddViewController
#synthesize empName;
#synthesize empID;
#synthesize empDepartment;
#synthesize backButton;
// The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
/*
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization.
}
return self;
}
*/
/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
}
*/
-(void)saveDetails{
EmployeeDetailsAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSManagedObject *newDetails;
newDetails = [NSEntityDescription insertNewObjectForEntityForName:#"Details" inManagedObjectContext:context];
[newDetails setValue:empID.text forKey:#"EmployeeID"];
[newDetails setValue:empName.text forKey:#"EmployeeName"];
[newDetails setValue:empDepartment.text forKey:#"EmployeeDepartment"];
empID.text = #"";
empName.text = #"";
empDepartment.text = #"";
NSLog(#"%#........----->>>...", newDetails);
NSError *error;
[context save:&error];
[self dismissModalViewControllerAnimated:YES];
}
-(void)findDetails {
EmployeeDetailsAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:#"Details" inManagedObjectContext:context];
NSFetchRequest *request = [[NSFetchRequest alloc]init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:#"(EmployeeName = %#)", empName.text];
[request setPredicate:pred];
NSManagedObject *matches = nil;
NSError *error;
NSArray *objects = [context executeFetchRequest:request error:&error];
if ([objects count] == 0) {
}
else {
matches = [objects objectAtIndex:0];
empID.text = [matches valueForKey:#"EmployeeID"];
empDepartment.text = [matches valueForKey:#"EmployeeDepartment"];
}
[request release];
[self dismissModalViewControllerAnimated:YES];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Overriden to allow any orientation.
return YES;
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc. that aren't in use.
}
- (void)viewDidUnload {
self.empName = nil;
self.empID = nil;
self.empDepartment = nil;
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[empID release];
[empName release];
[empDepartment release];
[super dealloc];
}
#end
Please let me know the answer as soon as possible.
#Dipanjan there is a core data tutorial in the devlopers document of X-Code and here it is coreDataBooks and its a best one try to take help from there in order to display the data in UITableView have a look at NSFetchedResultsController method.
http://www.bukisa.com/articles/180100_iphone-core-data-tutorial-part-1
http://mobile.tutsplus.com/tutorials/iphone/iphone-core-data/
Good Luck!
You need to fetch the data from the data using NSFetchResult. I guess you are doing it in the findDetails method, but where are you calling that method? You need to call that method to fetch the data, and then try to reload the table