NSUserDefaults not appearing first appearence - objective-c

Question

So I've been learning iOS for the past couple months and have recently ran into this problem. I have a settings screen inside my app after a log in process that should save some basic information pertaining to the user. The issue is when the view first appears from a tab bar controller, the static grouped table view is blank with none of the information available for the cell.detailLabel.text. I used NSLog to discover that at first when retrieving the objects from keys, they are null. However, when I select a cell to change it's information and push on another view controller, I can then go back and all the values will appear from previous inputs saved to NSUser defaults. I was curious why this happens and for a solution. Thanks
#import "SettingsController.h"
#import <Parse/Parse.h>
#import "LogInViewController.h"
#import "AddSettings.h"
#import "AddUrination.h"
#import "ChooseAlarmController.h"
#interface SettingsController ()
#end
#implementation SettingsController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
UIBarButtonItem *addUrination=[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(addUrinationView:)];
self.navigationItem.rightBarButtonItem=addUrination;
/*Rename the back button which every pushed on controller will have*/
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:#"Cancel" style:UIBarButtonItemStyleBordered target:nil action:nil];
self.navigationItem.backBarButtonItem = backButton;
NSLog(#"view loaded");
}
-(void)viewWillAppear:(BOOL)animated
{
/*Everytime view appears, we want to repopulate the table with updated content*/
NSLog(#"Settings View appeared,Load the keys");
/*Load every cell with appropiate details*/
NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
NSIndexPath *path=[NSIndexPath indexPathForRow:0 inSection:0];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:path];
cell.detailTextLabel.text=[defaults objectForKey:#"FirstNameKey"];
NSLog(#"%#",cell.detailTextLabel.text);
path=[NSIndexPath indexPathForRow:1 inSection:0];
cell=[self.tableView cellForRowAtIndexPath:path];
cell.detailTextLabel.text=[defaults objectForKey:#"LastNameKey"];
path=[NSIndexPath indexPathForRow:2 inSection:1];
cell=[self.tableView cellForRowAtIndexPath:path];
cell.detailTextLabel.text=[defaults objectForKey:#"NumberOfUrinationsKey"];
[self.tableView deselectRowAtIndexPath:self.tableView.indexPathForSelectedRow animated:YES];
path=[NSIndexPath indexPathForRow:0 inSection:1];
cell=[self.tableView cellForRowAtIndexPath:path];
cell.detailTextLabel.text=[defaults objectForKey:#"StartingAlarmKey"];
path=[NSIndexPath indexPathForRow:1 inSection:1];
cell=[self.tableView cellForRowAtIndexPath:path];
cell.detailTextLabel.text=[defaults objectForKey:#"FinalAlarmKey"];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(IBAction)addUrinationView:(id)sender
{
[self performSegueWithIdentifier:#"AddUrinationSegue" sender:self];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// If Log Out Button is selected
if(indexPath.row==0 && indexPath.section==2){
NSLog(#"Log Out selected");
[PFUser logOut];
UIAlertView *alert=[[UIAlertView alloc]initWithTitle:#"Are You Sure?" message:#"If you would like to change your mind, press cancel. Otherwise choose log out" delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:#"Log Out", nil];
[alert show];
}
NSLog(#"Selected row is %ld %ld", (long)indexPath.section,(long)indexPath.row);
/*Segue depends on which cell is selected. First section segues to text input (AddSettings.h)*/
if((indexPath.section==0 && indexPath.row<2) || (indexPath.section==1 && indexPath.row==2)){
[self performSegueWithIdentifier:#"AddSettingSegue" sender:self];
}
/*Choose alarm controller is selected*/
if(indexPath.section==1 && indexPath.row<2){
[self performSegueWithIdentifier:#"AddAlarmSegue" sender:self];
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
if([segue.identifier isEqualToString:#"AddSettingSegue"]){
AddSettings *settingsController=[segue destinationViewController];
/*index path contains both the section and row of the selected cell*/
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
NSLog(#"Section:%ld Row:%ld",(long)indexPath.section,(long)indexPath.row);
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
settingsController.titleOfController=cell.textLabel.text;
}
if([segue.identifier isEqualToString:#"AddUrinationSegue"])
{
AddUrination *addUrinationView=[segue destinationViewController];
}
if([segue.identifier isEqualToString:#"AddAlarmSegue"]){
ChooseAlarmController *alarm=[segue destinationViewController];
NSIndexPath *indexPath=[self.tableView indexPathForSelectedRow];
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
alarm.titleOfController=cell.textLabel.text;
}
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if(buttonIndex==1){
[self performSegueWithIdentifier:#"UnwindToLogIn" sender:self];
}
}
#end

Answer 1

Add [super viewWillAppear:animated] to the top of your viewWillAppear: override. According to Apple's documentation for viewWillAppear:,
"If you override this method, you must call super at some point in your implementation."
While your application generally won't crash or anything if you omit it, important initialization performed by the base class will not occur unless you call [super viewWillAppear:animated], which may result in unexpected behaviour, such as label values not appearing in your table view cells.
As a best practice, you should always call the super method whenever you override one of Apple's methods, unless you explicitly do not want the default behaviour to occur (eg. overriding touchesBegan:withEvent:). Though there are exceptions, generally overridden initialization methods like viewDidLoad and viewWillAppear: should call their super method at the beginning of the method, while overridden teardown methods like viewWillDisappear: should call their super method at the end.