Segue from TableViewCell NIB to ViewController - Pls have a look - ios

Question

After hours if trying to solve this error i decided to reach out for
help. I Keep on getting the same error :
"Terminating app due to uncaught
exception 'NSInvalidArgumentException', reason: '***
-[__NSCFConstantString stringByAppendingString:]: nil argument'"
#import <UIKit/UIKit.h>
#interface BrowseTableViewController : UITableViewController
#property (strong) NSMutableArray *emp; //An array to store all the information of clicked entries
#end
#import <CoreData/CoreData.h>
#import "BrowseClickViewController.h"
#import "ItemTableViewCell.h"
#interface BrowseTableViewController ()<UITableViewDelegate, UITableViewDataSource>
#end
#implementation BrowseTableViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.navigationItem.rightBarButtonItem = self.editButtonItem;
[self.tableView registerNib:[UINib nibWithNibName:#"ItemTableViewCell" bundle:[NSBundle mainBundle]] forCellReuseIdentifier:#"Cell1"];
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
// Return YES if you want the specified item to be editable.
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
//add code here for when you hit delete
[_emp removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView reloadData];
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (NSManagedObjectContext *)managedObjectContext
{
NSManagedObjectContext *context = nil;
id delegate = [[UIApplication sharedApplication] delegate];
if ([delegate performSelector:#selector(managedObjectContext)]) {
context = [delegate managedObjectContext];
}
return context;
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSManagedObjectContext *managedObjectContext = [self managedObjectContext];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"Employee"];
self.emp = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy]; // Obtaining all the entries of persistance store to show in Table view
[self.tableView reloadData];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.emp.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell1";
ItemTableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
NSManagedObject *empp = [self.emp objectAtIndex:indexPath.row]; //obtaining the informatio of selected row in empp object
[cell.itemName setText:[NSString stringWithFormat:#"%#", [empp valueForKey:#"name"]]];
[cell.quantityLabel setText:[NSString stringWithFormat:#"%#", [empp valueForKey:#"quantity"]]];
[cell.shopLabel setText:[NSString stringWithFormat:#"%#", [empp valueForKey:#"store"]]];
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
BrowseClickViewController *initViewController = [storyBoard instantiateViewControllerWithIdentifier:#"Click"];
[self.navigationController presentViewController:initViewController animated:YES completion:nil];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{ //Segue which is called when user selects any row, and this segue modifies the value of emp object of BrowseClickViewController with the clicked row details.
if ([segue.identifier isEqualToString:#"recordClicked"]){
NSManagedObject *selectedEmp = [self.emp objectAtIndex:[[self.tableView indexPathForSelectedRow] row]];
BrowseClickViewController *destViewController = segue.destinationViewController;
destViewController.emp = selectedEmp;
}
}
#end
#import <UIKit/UIKit.h>
#import <CoreData/CoreData.h>
#interface BrowseClickViewController : UIViewController
#property (weak, nonatomic) IBOutlet UIScrollView *scroller;
#property (weak, nonatomic) IBOutlet UILabel *barcodeLabel;
#property (weak, nonatomic) IBOutlet UILabel *categoryLabel;
#property (weak, nonatomic) IBOutlet UILabel *nameLabel;
#property (weak, nonatomic) IBOutlet UILabel *priceLabel;
#property (weak, nonatomic) IBOutlet UILabel *quantityLabel;
#property (weak, nonatomic) IBOutlet UILabel *storeLabel;
#property (weak, nonatomic) IBOutlet UIImageView *imagePicture;
#property (strong) NSManagedObject *emp;
#property (weak, nonatomic) NSString *picLabel;
#end
#import "BrowseClickViewController.h"
#import "BrowseTableViewController.h"
#import <CoreData/CoreData.h>
#import "ItemTableViewCell.h"
#interface BrowseClickViewController ()
#end
#implementation BrowseClickViewController
- (NSManagedObjectContext *)managedObjectContext {
NSManagedObjectContext *context = nil;
id delegate = [[UIApplication sharedApplication] delegate];
if ([delegate performSelector:#selector(managedObjectContext)]) {
context = [delegate managedObjectContext];
}
return context;
}
- (void)viewDidLoad {
[super viewDidLoad];
_nameLabel.text=[#"Name:" stringByAppendingString:[self.emp valueForKey:#"name"]];
_barcodeLabel.text=[#"Barcode:" stringByAppendingString:[self.emp valueForKey:#"barcode"]];
_categoryLabel.text=[#"Category:" stringByAppendingString:[self.emp valueForKey:#"category"]];
_priceLabel.text=[#"Price:"stringByAppendingString:[self.emp valueForKey:#"price"]];
_quantityLabel.text=[#"Quantity:" stringByAppendingString:[self.emp valueForKey:#"quantity"]];
_storeLabel.text=[#"Store:" stringByAppendingString:[self.emp valueForKey:#"store"]];
_picLabel=[self.emp valueForKey:#"pic"];
_imagePicture.image=[self loadImage:_picLabel];
}
-(UIImage *)loadImage: (NSString *)name
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithString:name]];
UIImage* image = [UIImage imageWithContentsOfFile:path];
return image;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
#end
#import <UIKit/UIKit.h>
#interface ItemTableViewCell : UITableViewCell
#property (nonatomic, weak) IBOutlet UILabel *itemName;
#property (nonatomic, weak) IBOutlet UILabel *quantityLabel;
#property (nonatomic, weak) IBOutlet UILabel *shopLabel;
#end
#import "ItemTableViewCell.h"
#import "BrowseClickViewController.h"
#implementation ItemTableViewCell
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
}
return self;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
BrowseClickViewController *initViewController = [storyBoard instantiateInitialViewController];
[self.window setRootViewController:initViewController];
}
#end

Answer 1

Most possibly , reason is that some of your appended strings values are nil.Do defensive coding.Check the below code sample and change all your code accordingly.
if([self.emp valueForKey:#"name"])
{
_nameLabel.text=[#"Name:" stringByAppendingString:[self.emp valueForKey:#"name"]];
}