TableviewController delegate not returning value - ios

Question

I have a tableview controller that is a static table used for request data. When someone selects a row, it displays a new tableview controller with options using a modal segue, the user selects a option and then presses the 'hecho' (done) button and the value should be returned to the first table view controller, but it just not happening. If I inspect the delegate it just says null. What could I be doing wrong?
The story board
First table
AgregarCitaTableViewController.h
#import <UIKit/UIKit.h>
#import "SeleccionarPacienteTableViewController.h"
#interface AgregarCitaTableViewController : UITableViewController <SeleccionarPacienteTableViewControllerDelegate>
#end
AgregarCitaTableViewController.m
#import "AgregarCitaTableViewController.h"
#import "SeleccionarPacienteTableViewController.h"
#interface AgregarCitaTableViewController ()
{
NSDictionary *datosPaciente;
}
#end
#implementation AgregarCitaTableViewController
- (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;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)paciente:(NSDictionary *)paciente
{
datosPaciente = paciente;
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
cell.detailTextLabel.text = [datosPaciente objectForKey:#"nombre"];
}
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if( [segue.identifier isEqualToString:#"listaPacientes"] )
{
SeleccionarPacienteTableViewController *viewController = segue.destinationViewController;
viewController.delegate = self;
}
}
Second Table
SeleccionarPacienteTableViewController.h
#protocol SeleccionarPacienteTableViewControllerDelegate <NSObject>
-(void)paciente:(NSDictionary *)paciente;
#end
#interface SeleccionarPacienteTableViewController : UITableViewController
{
id delegate;
}
#property(nonatomic,assign)id<SeleccionarPacienteTableViewControllerDelegate> delegate;
#end
SeleccionarPacienteTableViewController.m
#import "SeleccionarPacienteTableViewController.h"
#interface SeleccionarPacienteTableViewController ()
{
NSMutableArray *todosPacientes;
NSDictionary *paciente;
NSInteger checkmarkedRow;
}
#end
#implementation SeleccionarPacienteTableViewController
#synthesize delegate = _delegate;
- (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 *hecho = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:#selector(hecho)];
[[self navigationItem] setRightBarButtonItem:hecho];
UIBarButtonItem *cancelar = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:#selector(cancelar)];
[[self navigationItem] setLeftBarButtonItem:cancelar];
//Llamada asincrona, cargar las citas
[self performSelectorInBackground:#selector(cargarDatos) withObject:nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#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
{
#warning Incomplete method implementation.
// Return the number of rows in the section.
return todosPacientes.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
// Configure the cell...
NSDictionary *object;
object = todosPacientes[indexPath.row];
cell.textLabel.text = [object objectForKey:#"nombre"];
if(checkmarkedRow == indexPath.row){
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}else
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//Guardar nombre del paciente selccionado
paciente = todosPacientes[indexPath.row];
// In cellForRow... we check this variable to decide where we put the checkmark
checkmarkedRow = indexPath.row;
// We reload the table view and the selected row will be checkmarked
[tableView reloadData];
// We select the row without animation to simulate that nothing happened here :)
[tableView selectRowAtIndexPath:indexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
// We deselect the row with animation
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
- (void) cargarDatos
{
//Path donde se encuentra el plist con los datos
NSString *path = [[NSBundle mainBundle]pathForResource:#"pacientes" ofType:#"plist"];
//Guardamos las citas en un NSMutableArray
todosPacientes = [[NSMutableArray alloc]initWithContentsOfFile:path];
}
- (void) hecho
{
/*Is anyone listening
if([delegate respondsToSelector:#selector(paciente:)])
{
//send the delegate function with the amount entered by the user
[delegate paciente:paciente];
}*/
[self.delegate paciente:paciente];
[self dismissViewControllerAnimated:YES completion:nil];
}
- (void) cancelar
{
[self dismissViewControllerAnimated:YES completion:nil];
}
#end
Solution:
Im not really sure how it worked or even if this is the real solution. I used the anwer of Hani Ibrahim and it didn't work but what he said was right. Then i just changed [delegate paciente:paciente] in the hecho method for [self.delegate paciente:paciente] and it worked.
I hope this can help someone.

Answer 1

The problem is that your seque display UINavigationController and not SeleccionarPacienteTableViewController
Change this method
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if( [segue.identifier isEqualToString:#"listaPacientes"] )
{
SeleccionarPacienteTableViewController *viewController = segue.destinationViewController;
viewController.delegate = self;
}
}
to be
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if( [segue.identifier isEqualToString:#"listaPacientes"] )
{
UINavigationController *navController = segue.destinationViewController;
SeleccionarPacienteTableViewController *viewController = [navController.viewControllers objectAtIndex:0];
viewController.delegate = self;
}
}
You have another problem
When doing this
#property(nonatomic,assign)id<SeleccionarPacienteTableViewControllerDelegate> delegate;
and this
#synthesize delegate = _delegate;
Then Your property will work with an instance variable called '_delegate' as you are saying #synthesize delegate = _delegate;
However this code
#interface SeleccionarPacienteTableViewController : UITableViewController
{
id delegate;
}
defines a new instance variable called delegate which is completely different than your property
So to access your property you can use self.delegate or _delegate and NOT delegate as it is another instance variable !

Answer 2

I think the problem is in prepareForSegue. The destinationViewController is a UINavigationController and not a SeleccionarPacienteTableViewController.
You have to access the first child of the destinationViewController to get your SeleccionarPacienteTableViewController.
Replacing segue.destinationViewController with [segue.destinationViewController topViewController] will probably solve your problem.