Can't get a tableviewcontroller to reload after adding a new element - ios

Question

So I've been trying this for a while now and it is completely frustrating me but here is a brief summary of what I am trying to do. I have a LocationTableViewController with a plus button on the top right to add new locations to the table view. When that happens, I enter the LocationEditViewController where I can enter the name of the location I want to add. After adding my text and hitting the save location button I want the code to bring me back to the LocationTableViewController and there in my table I see my newly added location. Posted below is the code of the two view controllers. Hopefully you guys can help me thanks a ton!!
#import <UIKit/UIKit.h>
#import "Location.h"
#import "User.h"
#interface LocationEditViewController : UIViewController <UITextFieldDelegate>
#property (strong, nonatomic) Location *location;
#property (strong, nonatomic) User *user;
#property (strong, nonatomic) UITextField *locationNameField;
- (void)saveLocation:(id) sender;
#end
#import "LocationEditViewController.h"
#interface LocationEditViewController ()
#end
#implementation LocationEditViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.title = #"Edit";
self.location = [[Location alloc] init];
self.user = [[User alloc] init];
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
UILabel *locationLabel = [[UILabel alloc] init];
locationLabel.frame = CGRectMake(20,15,50,30);
locationLabel.text = #"Name:";
[self.view addSubview:locationLabel];
self.locationNameField = [[UITextField alloc] init];
self.locationNameField.frame = CGRectMake(15,50,290,30);
self.locationNameField.borderStyle = UITextBorderStyleBezel;
self.locationNameField.keyboardType = UIKeyboardTypeDefault;
self.locationNameField.delegate = self;
[self.view addSubview:self.locationNameField];
UIButton *saveLocationButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
saveLocationButton.frame = CGRectMake(15,400,290,50);
[saveLocationButton setTitle:#"Save Location" forState:UIControlStateNormal];
[saveLocationButton addTarget:self action:#selector(saveLocation:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:saveLocationButton];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return YES;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)saveLocation:(id)sender {
self.location.name = self.locationNameField.text;
NSMutableArray *tempArray = [[NSMutableArray alloc] initWithArray:self.user.createdLocations];
[tempArray addObject:self.location];
self.user.createdLocations = [[NSArray alloc] initWithArray:tempArray];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Location Added"
message:#"This location is now accessable in the locations tab"
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
[self.tabBarController.tabBar.items[1] setBadgeValue:[NSString stringWithFormat:#"%i",self.user.createdLocations.count]];
[self dismissViewControllerAnimated:YES completion:^{
[[NSNotificationCenter defaultCenter] postNotificationName:#"somethingAddedNotification" object:nil];
}];
}
/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
#end
Here is the LocationTableViewController code:
#import <UIKit/UIKit.h>
#import "User.h"
#interface LocationTableViewController : UITableViewController
#property (strong, nonatomic) NSArray *locations;
#property (strong, nonatomic) User *user;
#property (strong, nonatomic) id _observer;
- (void) addLocationPressed;
#end
#import "LocationTableViewController.h"
#import "LocationEditViewController.h"
#import "LocationViewController.h"
#interface LocationTableViewController ()
#end
#implementation LocationTableViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
self.title = #"Locations";
self.user = [[User alloc] init];
UIBarButtonItem *addLocationButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(addLocationPressed)];
self.navigationItem.rightBarButtonItem = addLocationButton;
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
//Location *loc = [[Location alloc] init];
//self.user.createdLocations = #[loc];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (void) addLocationPressed
{
LocationEditViewController *locationEditVC = [[LocationEditViewController alloc] init];
[self presentViewController:locationEditVC animated:YES completion:nil];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.user.createdLocations.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
if(cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"Cell"];
}
cell.textLabel.text = [self.user.createdLocations[indexPath.row] name];
NSLog(#"%#", [self.user.createdLocations[indexPath.row] name]);
return cell;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
LocationViewController *locationVC = [[LocationViewController alloc] init];
locationVC.location = self.user.createdLocations[indexPath.row];
[self.navigationController pushViewController:locationVC animated:YES];
}
- (void)viewWillAppear:(BOOL)animated {
__observer = [[NSNotificationCenter defaultCenter] addObserverForName:#"somethingAddedNotification"
object:nil
queue:nil
usingBlock:^(NSNotification *notification)
{
[self.tableView reloadData];
}];
}
- (void)viewWillDisappear:(BOOL)animated {
[[NSNotificationCenter defaultCenter] removeObserver:__observer];
}
For additional information here is the user class where I am getting the array
#import <Foundation/Foundation.h>
#import "Location.h"
#interface User : NSObject
#property (strong, nonatomic) Location *profilePhoto;
#property (strong, nonatomic) NSString *location;
#property (strong, nonatomic) NSArray *createdLocations;
-(id) initWithTitle: (Location *) aLoc
detail: (NSString *) aDet
filename: (NSArray *) aLocList;
//-(id)initWithJSON;
//+(NSString *)getPathToArchive;
//+(User *)getUser;
//+(void)saveUser:(User *)aUser;
#end
#import "User.h"
#import "Location.h"
#implementation User
- (id)init;
{
self = [self initWithTitle: [[Location alloc] init]
detail: #"Temp"
filename: [[NSArray alloc] init]];
return self;
}
-(id) initWithTitle: (Location *) aLoc
detail: (NSString *) aDet
filename: (NSArray *) aLocList
{
self = [super init];
if (self) {
self.profilePhoto = aLoc;
self.location = aDet;
self.createdLocations = aLocList;
}
return self;
}
#end
and the Locations class if necessary
#import <Foundation/Foundation.h>
#interface Location : NSObject
#property (strong, nonatomic) NSString *name;
#property (strong, nonatomic) NSString *detail;
#property (strong, nonatomic) NSString *filename;
#property (strong, nonatomic) NSString *thumbnail;
-(id) initWithTitle: (NSString *) aTitle
detail: (NSString *) aDetail
filename: (NSString *) aFilename
thumbnail: (NSString *) aThumbnail;
#end
#import "Location.h"
#implementation Location
-(id)init
{
self = [self initWithTitle:#"Title"
detail:#"Detail"
filename:#"placeholder.jpg"
thumbnail:#"placeholder.jpg"];
return self;
}
-(id)initWithTitle:(NSString *)aTitle
detail:(NSString *)aDetail
filename:(NSString *)aFilename
thumbnail:(NSString *)aThumbnail
{
self = [super init];
if (self) {
self.name = aTitle;
self.detail = aDetail;
self.filename = aFilename;
self.thumbnail = aThumbnail;
}
return self;
}
#end
Hopefully you guys can help me! Thanks again!!!

Answer 1

Have you set a breakpoint on...
[self.tableView reloadData];
...in your observer block? Does it get hit? Separately, Drew Crawford is wary of that API you are using (http://sealedabstract.com/code/nsnotificationcenter-with-blocks-considered-harmful/).

Answer 2

Like the comment said, this is definitely a problem, and may in fact be the root cause. You must use the __weak reference inside the block or else NSNotificationCenter owns a strong reference to self and self owns a strong reference to NSNotificationCenter, and you have a retain cycle.
- (void)viewWillAppear:(BOOL)animated {
__weak LocationTableViewController *weakSelf = self;
__observer = [[NSNotificationCenter defaultCenter] addObserverForName:#"somethingAddedNotification"
object:nil
queue:nil
usingBlock:^(NSNotification *notification)
{
[weakSelf.tableView reloadData];
}];
}