I have a strange problem: I got a DetailViewController inside a SplitViewController which holds a button. This button has a Popover segue to a NavigationController and UITableViewController which acts as a notepad. The first time I open the popover, the notepad works excellent, just as expected. However, if I close the popover and then reopen it, it'll fail when I add or delete a note. Functionality is restored once app is restarted.
Add code blamed:
[_objects insertObject:newNote atIndex:0];
Delete code blamed:
[_objects removeObjectAtIndex:indexPath.row];
Almost entire NotesViewController.m class:
#import "NotesTableViewController.h"
@interface NotesTableViewController ()
{
NSMutableArray *_objects;
BOOL firstRun;
}
@end
@implementation NotesTableViewController
@synthesize openSubject;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)awakeFromNib
{
self.clearsSelectionOnViewWillAppear = NO;
self.preferredContentSize = CGSizeMake(320.0, 600.0);
[super awakeFromNib];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Load the notes data
// Create the key
NSString *partOfKey = @"-notes";
NSString *notesKey = [NSString stringWithFormat:@"%@%@", openSubject, partOfKey];
// Do any additional setup after loading the view, typically from a nib
self.navigationItem.leftBarButtonItem = self.editButtonItem;
// Register a class or nib file using registerNib:forCellReuseIdentifier
// o registerClass:forCellReuiseIdentifier: method before calling this method
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"Cell"];
// Load the _objects from NSUserdefaults
_objects = nil;
_objects = [[NSUserDefaults standardUserDefaults] objectForKey:notesKey];
if (openSubject.length == 0) {
// There's currently no subject open, write it in the navigationbar
// Prompt = open subject
// Title = notes header
self.navigationItem.prompt = @"No subject selected";
self.navigationItem.title = @"My Notes";
} else {
// Open the subject
// Prompt = notes header
// Title = open subject
self.navigationItem.prompt = openSubject;
self.navigationItem.title = @"My notes";
}
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)addNote:(id)sender {
// Create a new note
if (openSubject.length == 0) {
// The openSubject is nil, can't add a subject - tell the user
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"No subject" message: @"Please select a subject prior to adding a note" delegate: nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show];
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"New note" message:@"Enter a note" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Add", nil];
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
[alert show];
}
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
// The user created a new subject, add it
if (buttonIndex == 1) {
// Get the input text
NSString *newNote = [[alertView textFieldAtIndex:0] text];
// Check if the note already exist
if ([_objects containsObject:newNote]) {
// Tell the user this note already exists
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Already exists" message: @"This note already exist, sorry" delegate: nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
} else {
// The note doesn't exist, add it
// Initialize objects
if (!_objects) {
_objects = [[NSMutableArray alloc] init];
}
// Add
[_objects insertObject:newNote atIndex:0];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
// Save the new _objects
[self saveObjects];
}
}
}
-(void)saveObjects {
// Create the key
NSString *partOfKey = @"-notes";
// Save the new objects
NSString *notesKey = [NSString stringWithFormat:@"%@%@", openSubject, partOfKey];
[[NSUserDefaults standardUserDefaults] setObject:_objects forKey:notesKey];
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
#warning Potentially incomplete method implementation.
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return _objects.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
NSString *object = _objects[indexPath.row];
cell.textLabel.text = [object description];
return cell;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
[_objects removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
Debugger output:
2014-05-21 20:43:14.564 myApp[263:60b] viewDidAppear 2014-05-21 20:43:15.093 myApp[263:60b] viewDidAppear 2014-05-21 20:43:29.741 myApp[263:60b] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object' * First throw call stack: (0x2d95bfd3 0x38440ccf 0x2d95bf15 0x2d8cfa93 0xf6e29 0x3038eb29 0x3038e7fb 0x3029605f 0x30348377 0x301f76f5 0x3017055b 0x2d9272a5 0x2d924c49 0x2d924f8b 0x2d88ff0f 0x2d88fcf3 0x32789663 0x301db16d 0xf9411 0x3894dab7) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)
Please help me solve this, I have no idea.
Thanks in advance
When you get your array back from NSUserDefaults it returns a immutable array. You'll need to get a mutableCopy or do a _objects = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:notesKey]];