#238: Migration code

2012-10-16 10:42:15 +02:00 · 2012-10-16 10:42:15 +02:00 · ff1a6eecea
commit ff1a6eecea
parent 01116aa515
15 changed files with 969 additions and 2 deletions
--- a/Photo/CoreDataTableViewController.m
+++ b/Photo/CoreDataTableViewController.m
@ -0,0 +1,177 @@
+//
+//  CoreDataTableViewController.m
+//
+//  Created for Stanford CS193p Fall 2011.
+//  Copyright 2011 Stanford University. All rights reserved.
+//
+
+#import "CoreDataTableViewController.h"
+
+@interface CoreDataTableViewController()
+@property (nonatomic) BOOL beganUpdates;
+@end
+
+@implementation CoreDataTableViewController
+
+#pragma mark - Properties
+
+@synthesize fetchedResultsController = _fetchedResultsController;
+@synthesize suspendAutomaticTrackingOfChangesInManagedObjectContext = _suspendAutomaticTrackingOfChangesInManagedObjectContext;
+@synthesize debug = _debug;
+@synthesize beganUpdates = _beganUpdates;
+
+- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
+{
+    return YES;
+}
+
+#pragma mark - Fetching
+
+- (void)performFetch
+{
+    if (self.fetchedResultsController) {
+        if (self.fetchedResultsController.fetchRequest.predicate) {
+            if (self.debug) NSLog(@"[%@ %@] fetching %@ with predicate: %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), self.fetchedResultsController.fetchRequest.entityName, self.fetchedResultsController.fetchRequest.predicate);
+        } else {
+            if (self.debug) NSLog(@"[%@ %@] fetching all %@ (i.e., no predicate)", NSStringFromClass([self class]), NSStringFromSelector(_cmd), self.fetchedResultsController.fetchRequest.entityName);
+        }
+        NSError *error = nil;
+        [self.fetchedResultsController performFetch:&error];
+        if (error) NSLog(@"[%@ %@] %@ (%@)", NSStringFromClass([self class]), NSStringFromSelector(_cmd), [error localizedDescription], [error localizedFailureReason]);
+    } else {
+        if (self.debug) NSLog(@"[%@ %@] no NSFetchedResultsController (yet?)", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
+    }
+    [self.tableView reloadData];
+}
+
+- (void)setFetchedResultsController:(NSFetchedResultsController *)newfrc
+{
+    NSFetchedResultsController *oldfrc = _fetchedResultsController;
+    if (newfrc != oldfrc) {
+        _fetchedResultsController = newfrc;
+        newfrc.delegate = self;
+        if ((!self.title || [self.title isEqualToString:oldfrc.fetchRequest.entity.name]) && (!self.navigationController || !self.navigationItem.title)) {
+            self.title = newfrc.fetchRequest.entity.name;
+        }
+        if (newfrc) {
+            if (self.debug) NSLog(@"[%@ %@] %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), oldfrc ? @"updated" : @"set");
+            [self performFetch]; 
+        } else {
+            if (self.debug) NSLog(@"[%@ %@] reset to nil", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
+            [self.tableView reloadData];
+        }
+    }
+}
+
+#pragma mark - UITableViewDataSource
+
+- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
+{
+    return [[self.fetchedResultsController sections] count];
+}
+
+- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
+{
+    return [[[self.fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
+}
+
+- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
+{
+	return [[[self.fetchedResultsController sections] objectAtIndex:section] name];
+}
+
+- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index
+{
+	return [self.fetchedResultsController sectionForSectionIndexTitle:title atIndex:index];
+}
+
+- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
+{
+    return [self.fetchedResultsController sectionIndexTitles];
+}
+
+#pragma mark - NSFetchedResultsControllerDelegate
+
+- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
+{
+    if (!self.suspendAutomaticTrackingOfChangesInManagedObjectContext) {
+        [self.tableView beginUpdates];
+        self.beganUpdates = YES;
+    }
+}
+
+- (void)controller:(NSFetchedResultsController *)controller
+  didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
+		   atIndex:(NSUInteger)sectionIndex
+	 forChangeType:(NSFetchedResultsChangeType)type
+{
+    if (!self.suspendAutomaticTrackingOfChangesInManagedObjectContext)
+    {
+        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
+{		
+    if (!self.suspendAutomaticTrackingOfChangesInManagedObjectContext)
+    {
+        switch(type)
+        {
+            case NSFetchedResultsChangeInsert:
+                [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
+                break;
+                
+            case NSFetchedResultsChangeDelete:
+                [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
+                break;
+                
+            case NSFetchedResultsChangeUpdate:
+                [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
+                break;
+                
+            case NSFetchedResultsChangeMove:
+                [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
+                [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
+                break;
+        }
+    }
+}
+
+- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
+{
+    if (self.beganUpdates) {
+        self.beganUpdates = NO;
+        [self.tableView endUpdates];
+    }
+}
+
+- (void)endSuspensionOfUpdatesDueToContextChanges
+{
+    _suspendAutomaticTrackingOfChangesInManagedObjectContext = NO;
+}
+
+- (void)setSuspendAutomaticTrackingOfChangesInManagedObjectContext:(BOOL)suspend
+{
+    if (suspend) {
+        _suspendAutomaticTrackingOfChangesInManagedObjectContext = YES;
+    } else {
+        [self performSelector:@selector(endSuspensionOfUpdatesDueToContextChanges) withObject:0 afterDelay:0];
+    }
+}
+
+@end
+