objective-c : Core Data Essential (CDCourses)

Core Data Essential (CDCourses).m

//Core Data Essential (CDCourses)


//Course.h

#import <CoreData/CoreData.h>

@interface Course : NSManagedObject

@property (nonatomic, retain) NSString * title;
@property (nonatomic, retain) NSString * author;
@property (nonatomic, retain) NSDate * releaseDate;

@end


//Course.m

@implementation Course

@dynamic title;
@dynamic author;
@dynamic releaseDate;

//Invoked automatically by the Core Data framework when the receiver is first inserted into a managed object context.
//typically use this method to initialize special default property values. 
//awakeFromInsert method is invoked only once in the object's lifetime
- (void) awakeFromInsert
{
    [super awakeFromInsert];
    self.releaseDate = [NSDate date];
}

@end



//AppDelegate.h

#import "CoursesTableViewController.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;

- (void)saveContext;
- (NSURL *)applicationDocumentsDirectory;

@end



//AppDelegate.m

@implementation AppDelegate

@synthesize managedObjectContext = _managedObjectContext;
@synthesize managedObjectModel = _managedObjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // 스토리보드를 사용하므로 스텁 코드는 삭제함.
    
    // 루트 뷰로 내비게이션컨트롤러 설정 및 managedObjectContext 참조
    UINavigationController *nav = (UINavigationController *)self.window.rootViewController;
    CoursesTableViewController *ctvc = (CoursesTableViewController *)[[nav viewControllers] objectAtIndex:0];
    ctvc.managedObjectContext = self.managedObjectContext;
    
    return YES;
}


- (void)applicationWillTerminate:(UIApplication *)application
{
    // Saves changes in the application's managed object context before the application terminates.
    [self saveContext];
}

- (void)saveContext
{
    NSError *error = nil;
    NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
    if (managedObjectContext != nil) {
        if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
             
            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
        } 
    }
}


#pragma mark - Core Data stack

// Returns the managed object context for the application.
// If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
- (NSManagedObjectContext *)managedObjectContext
{
    if (_managedObjectContext != nil) {
        return _managedObjectContext;
    }
    
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        _managedObjectContext = [[NSManagedObjectContext alloc] init];
        [_managedObjectContext setPersistentStoreCoordinator:coordinator];
    }
    return _managedObjectContext;
}

// Returns the managed object model for the application.
// If the model doesn't already exist, it is created from the application's model.
- (NSManagedObjectModel *)managedObjectModel
{
    if (_managedObjectModel != nil) {
        return _managedObjectModel;
    }
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"CDCourses" withExtension:@"momd"];
    _managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    return _managedObjectModel;
}

// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }
    
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"CDCourses.sqlite"];
    
    NSError *error = nil;
    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
        /*
         Replace this implementation with code to handle the error appropriately.
         */
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }    
    
    return _persistentStoreCoordinator;
}


#pragma mark - Application's Documents directory

// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}

@end




//AddCourseViewController.h

#import "Course.h"

@protocol AddCourseViewControllerDelegate;

@interface AddCourseViewController : UIViewController

@property (weak, nonatomic) IBOutlet UITextField *titleField;
@property (weak, nonatomic) IBOutlet UITextField *authorField;
@property (weak, nonatomic) IBOutlet UITextField *dateField;

@property (nonatomic, weak) id <AddCourseViewControllerDelegate> delegate;

@property (nonatomic, strong) Course *currentCourse;


- (IBAction)cancel:(id)sender;
- (IBAction)save:(id)sender;

@end


@protocol AddCourseViewControllerDelegate

- (void) addCourseViewControllerDidSave;
- (void) addCourseViewControllerDidCancel:(Course *)courseToDelete;

@end



//  AddCourseViewController.m

@interface AddCourseViewController ()

@end

@implementation AddCourseViewController

@synthesize titleField;
@synthesize authorField;
@synthesize dateField;


#pragma mark - 뷰 라이프 사이클

- (void)viewDidLoad
{
    [super viewDidLoad];
	
    titleField.text = [self.currentCourse title];
    authorField.text = [self.currentCourse author];
    
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    dateField.text = [dateFormat stringFromDate:[self.currentCourse releaseDate]];
    
}


- (IBAction)cancel:(id)sender {
    // 모달 뷰 팝 / 오브젝트 제거
    [self.delegate addCourseViewControllerDidCancel:[self currentCourse]];
}


- (IBAction)save:(id)sender {
    // 모달 뷰 팝 / 컨텍스트 저장
    [self.currentCourse setTitle:titleField.text];
    [self.currentCourse setAuthor:authorField.text];
    
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"yyyy-mm-dd"];
    [self.currentCourse setReleaseDate:[dateFormat dateFromString:dateField.text]];
    
    [self.delegate addCourseViewControllerDidSave];
}


@end



//CoursesTableViewController.h

#import "AddCourseViewController.h"

// 컨텍스트의 저장/저장 취소/모달 뷰 해제를 위한 델리게이트
@interface CoursesTableViewController : UITableViewController <AddCourseViewControllerDelegate, NSFetchedResultsControllerDelegate>

// AppDelegate의 컨텍스트 참조
@property (nonatomic, strong) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, strong) NSFetchedResultsController *fetchedResultsController;


@end




//CoursesTableViewController.m

#import "Course.h"
#import "DisplayEditViewController.h"

@implementation CoursesTableViewController

@synthesize fetchedResultsController = _fetchedResultsController;


#pragma mark - addCourseViewControllerDelegate 메소드

- (void) addCourseViewControllerDidCancel:(Course *)courseToDelete
{
    NSManagedObjectContext *context = self.managedObjectContext;
    [context deleteObject:courseToDelete];
    
    [self dismissViewControllerAnimated:YES completion:nil];
}


- (void) addCourseViewControllerDidSave
{
    NSError *error = nil;
    
    NSManagedObjectContext *context = self.managedObjectContext;
    if (![context save:&error]) {
        NSLog(@"Error! %@", error);
    }
    
    [self dismissViewControllerAnimated:YES completion:nil];
}



#pragma mark - Segue 메소드

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    
    if ([[segue identifier] isEqualToString:@"addCourse"]) {
        
        AddCourseViewController *acvc = (AddCourseViewController *)[segue destinationViewController];
        acvc.delegate =self;
        
        Course *newCourse = (Course *) [NSEntityDescription insertNewObjectForEntityForName:@"Course" inManagedObjectContext:[self managedObjectContext]];
        
        acvc.currentCourse = newCourse;
    }
    
    if ([[segue identifier] isEqualToString:@"showDetail"]) {
        DisplayEditViewController *dvc = (DisplayEditViewController *) [segue destinationViewController];
        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        Course *selectedCourse = (Course *) [self.fetchedResultsController objectAtIndexPath:indexPath];
        dvc.currentCourse = selectedCourse;
    }
}


#pragma mark - 뷰 라이프 사이클

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // performFetch
    NSError *error = nil;
    if (![[self fetchedResultsController] performFetch:&error]) {
        NSLog(@"Error! %@", error);
        abort();
    }
    
}


#pragma mark - fetchedResultsController section (지연된 로딩)

-(NSFetchedResultsController *) fetchedResultsController {

    if (_fetchedResultsController != nil) {
        return _fetchedResultsController;
    }

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Course"
                                              inManagedObjectContext:[self managedObjectContext]];
    [fetchRequest setEntity:entity];
    
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"author"
                                                                   ascending:YES];
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
    [fetchRequest setSortDescriptors:sortDescriptors];
    
    // fetchedResultsController 엑세서 메소드
    _fetchedResultsController = [[NSFetchedResultsController alloc]
                                 initWithFetchRequest:fetchRequest
                                 managedObjectContext:self.managedObjectContext
                                 sectionNameKeyPath:@"author"
                                 cacheName:nil];
    
    _fetchedResultsController.delegate = self;
    
    return _fetchedResultsController;
}



#pragma mark - fetchedResultsController 델리게이트 메소드

-(void) controllerWillChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView beginUpdates];
}


-(void) controllerDidChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView endUpdates];
}


-(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: {
            Course *changedCourse = [self.fetchedResultsController objectAtIndexPath:indexPath];
            UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
            cell.textLabel.text = changedCourse.title;
        }
            break;
            
        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] 
            	withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] 
            	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;
    }
}



#pragma mark - Table view data source

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


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // <NSFetchedResultsSectionInfo> 프로토콜
    id <NSFetchedResultsSectionInfo> secInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
    return [secInfo numberOfObjects];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    
    // Configure the cell...
    
    Course *course = [self.fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = course.title;
    
    return cell;
}


- (NSString *) tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return [[[self.fetchedResultsController sections] objectAtIndex:section] name];
}


#pragma mark - Table view 에디팅 지원

// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        NSManagedObjectContext *context = [self managedObjectContext];
        Course *courseToDelete = [self.fetchedResultsController objectAtIndexPath:indexPath];
        [context deleteObject:courseToDelete];
        
        NSError *error = nil;
        if (![context save:&error]) {
            NSLog(@"Error! %@",error);
        }
    }
    
}


@end




//DisplayEditViewController.h

#import "Course.h"

@interface DisplayEditViewController : UIViewController

@property (nonatomic, strong) Course *currentCourse;

@property (weak, nonatomic) IBOutlet UITextField *titleField;
@property (weak, nonatomic) IBOutlet UITextField *authorField;
@property (weak, nonatomic) IBOutlet UITextField *dateField;

@property (weak, nonatomic) IBOutlet UIButton *editButton;
@property (weak, nonatomic) IBOutlet UIButton *doneButton;


- (IBAction)startEditing:(id)sender;
- (IBAction)doneEditing:(id)sender;


@end




//DisplayEditViewController.m

#import "DisplayEditViewController.h"
#import "AppDelegate.h"

@interface DisplayEditViewController ()

@end

@implementation DisplayEditViewController

@synthesize titleField;
@synthesize authorField;
@synthesize dateField;

@synthesize editButton;
@synthesize doneButton;


- (void)viewDidLoad
{
    [super viewDidLoad];
	
    titleField.text = [self.currentCourse title];
    authorField.text = [self.currentCourse author];
    
    NSDateFormatter *df = [[NSDateFormatter alloc]init];
    [df setDateFormat:@"yyyy-MM-dd"];
    dateField.text = [df stringFromDate:[self.currentCourse releaseDate]];
}


- (IBAction)startEditing:(id)sender {
    titleField.enabled = YES;
    authorField.enabled = YES;
    dateField.enabled = YES;
    
    titleField.borderStyle = UITextBorderStyleRoundedRect;
    authorField.borderStyle = UITextBorderStyleRoundedRect;
    dateField.borderStyle = UITextBorderStyleRoundedRect;
    
    editButton.hidden = YES;
    doneButton.hidden = NO;
}


- (IBAction)doneEditing:(id)sender {
    titleField.enabled = NO;
    authorField.enabled = NO;
    dateField.enabled = NO;
    
    titleField.borderStyle = UITextBorderStyleNone;
    authorField.borderStyle = UITextBorderStyleNone;
    dateField.borderStyle = UITextBorderStyleNone;
    
    editButton.hidden = NO;
    doneButton.hidden = YES;
    
    _currentCourse.title = titleField.text;
    _currentCourse.author = authorField.text;
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    [df setDateFormat:@"yyyy-MM-dd"];
    _currentCourse.releaseDate = [df dateFromString:dateField.text];
    
    // 앱 델리게이트 컨텍스트 저장
    AppDelegate *myApp = (AppDelegate *) [[UIApplication sharedApplication] delegate];
    [myApp saveContext];
}


@end