how to set value to textField through a delegate - ios

Question

i have two view controllers, view controller and tableViewController.
ViewController contains a textField and a button. when the button in viewController is clicked, then TableViewController should start.
in TableViewController, there is a list contains 5 rows, each row contains a string value.
What I am trying to do is, hen the user chooses any row in the list in TableViewController, then ViewController scene should start and the value that the user chose should be displayed in the textfield in ViewController.
to achieve this task, I created a protocol in TableViewController with a required method called valueChoosen: (NSString *) value, and this method is implemented in ViewController, and then I set the value to the textField but, at run time the TextField is empty.
please have look at the code below, and let me know why the value passed to the required method of the protocol can not be set to the textfield, what I am doing wrong;
TableViewController:
#import "TableViewController.h"
#interface TableViewController ()
#property NSArray *tableData;
#end
#implementation TableViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.tableData = [NSArray arrayWithObjects:#"Android",
#"iOS",
#"swift",
#"objective-c",
#"openCV",nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(NSInteger) tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section {
return [self.tableData count];
}
-(UITableViewCell *) tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *simpleTableIdentifier = #"SimpleTableItem";
UITableViewCell *cell = [tableView
dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:simpleTableIdentifier];
}
cell.textLabel.text = [self.tableData objectAtIndex:indexPath.row];
cell.imageView.image = [UIImage imageNamed:#"images.jpg"];
return cell;
}
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:
(NSIndexPath *)indexPath {
NSLog(#"%#", [self.tableData objectAtIndex:indexPath.row]);
[self performSegueWithIdentifier:#"unwindSegue" sender:NULL];
[self.delegate valueChoosen:[self.tableData
objectAtIndex:indexPath.row]];
}
#end
ViewController:
#import "ViewController.h"
#import "TableViewController.h"
#interface ViewController ()
#property (strong, nonatomic) IBOutlet UITextField
*textFieldDepartment;
#property (strong, nonatomic) IBOutlet UIButton
*buttonSelectFromTableView;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a
nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"segueToTableView"]) {
//code
TableViewController *table = segue.destinationViewController;
table.delegate = self;
}
}
-(void) valueChoosen: (NSString *) value {
[_textFieldDepartment setText:value];
NSLog(#"value: %#", value);
}
#end

Answer 1

It maybe because you are setting the textfield text in the viewController which is not being displayed. Try assigning the value to a variable using the delegate function and call the delegate function before performing the unwind segue. And on the viewController try setting the textfield text as the variable whose value was set through delegate method from the viewWillAppear method.

Answer 2

Step 1:
create the unwind action in the viewcontroller you want to unwind it.in your case it is ViewController
- (IBAction)unwindFromModalController:(UIStoryboardSegue *)segue{}
Step 2:
Connect to the unwind Action
Control drag from tableviewcell to the Exit sign.
Select the Action you specified.
Add the Identifier to unwind segue.
Step3
Trigger the segue
in your TableViewController.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
self.selectedText = self.tableData[indexPath.row];
[self performSegueWithIdentifier:#"unwindSegue" sender:self];}
Step 4:
Pass Data
Unwind Action
- (IBAction)unwindFromModalController:(UIStoryboardSegue *)segue{
if ([segue.sourceViewController isKindOfClass:[TableViewController class]]) {
TableViewController *vc = segue.sourceViewController;
if (vc.selectedText) {
[_textFieldDepartment setText:vc.selectedText];}
}
}