nnCoreDataTableViewController.m

//
//  nnCoreDataTableViewController.m
//  metime
//
//  Created by Brice Tebbs on 7/9/10.
//  Copyright 2010 northNitch Studios, Inc. All rights reserved.
//

#import "nnCoreDataTableViewController.h"


@implementation nnCoreDataTableViewController

@synthesize coreDataManager;
@synthesize fetchedResultsController;



- (void)dealloc {
    fetchedResultsController.delegate = nil;
    [fetchedResultsController release];
    [coreDataManager release];

    [super dealloc];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    
    if (!self.fetchedResultsController) {
        [self prepareFetchResultsController];
    }
    NSError *error;
	if (![self.fetchedResultsController performFetch:&error]) {
		// Update to handle the error appropriately.
		NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
		exit(-1);  // Fail
	}
}


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{
    NSInteger dataSections = [[fetchedResultsController sections] count];
    return dataSections;
}


// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
	id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
	return [sectionInfo numberOfObjects];
}




// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
    
}



-(BOOL)tableView:(UITableView*)tableView canEditRowAtIndexPath:(NSIndexPath*)indexPath {
    if( ![self isEditing] ) {
        return NO;
    }
    return YES;
};

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    
    if (editingStyle == UITableViewCellEditingStyleDelete) {
		// Delete the managed object.
		NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
		[context deleteObject:[fetchedResultsController objectAtIndexPath:indexPath]];
		
		NSError *error;
		if (![context save:&error]) {
            [coreDataManager handleError: error];
		}
    }   
}


- (void)configureCell:(UITableViewCell *)cell forItem: (id <nnCoreDataTableViewItemProtocol>) item
{
    cell.textLabel.text = [item listLabel];
}

-(UITableViewCell*)allocateACellIn:(UITableView *)tableView forItem: (id <nnCoreDataTableViewItemProtocol>) item
{
    UITableViewCell* cell;
    static NSString *kCellIdentifier = @"UITableViewCell";
    cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:kCellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCellIdentifier] autorelease];
    }
    
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    return cell;
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
	id <nnCoreDataTableViewItemProtocol> item = [fetchedResultsController objectAtIndexPath:indexPath];
    
    UITableViewCell* cell = [self allocateACellIn: tableView forItem: item];
    // Configure the cell
    [self configureCell: cell forItem: item];
    return cell;
}

-(void)updateCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
	
	id <nnCoreDataTableViewItemProtocol> item = [fetchedResultsController objectAtIndexPath:indexPath];
    [self configureCell: cell forItem: item];
}


#pragma mark -
#pragma mark Fetched results controller


/**
 Delegate methods of NSFetchedResultsController to respond to additions, removals and so on.
 */

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
	// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
	[self.tableView beginUpdates];
}


- (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 updateCell: [tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
			break;
			
    //
    //  I think we dont need this if we re-order the elements by changing the sort field in 
    //  -(void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath 
    //
//		case NSFetchedResultsChangeMove:
//			[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
//            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
//			// Reloading the section inserts a new row and ensures that titles are updated appropriately.
//			[tableView reloadSections:[NSIndexSet indexSetWithIndex:newIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
//			break;
	}
}


- (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)controllerDidChangeContent:(NSFetchedResultsController *)controller {
	// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
	[self.tableView endUpdates];
}


// Overridden by subclass
-(void)setupFetchRequest: (NSFetchRequest *)fetchRequest
{
}


- (nnErrorCode)prepareFetchResultsController
{

    
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    
    [self setupFetchRequest: fetchRequest];
    
    NSFetchedResultsController* frc = [[NSFetchedResultsController alloc] 
                                       initWithFetchRequest: fetchRequest
                                       managedObjectContext: self.coreDataManager.managedObjectContext
                                       sectionNameKeyPath:nil cacheName:nil];
	self.fetchedResultsController = frc;

	
    self.fetchedResultsController.delegate = self;
    
    [fetchRequest release];
    [frc release];
	
    return nnkNoError;
}    

@end