How does a table view controller communicate with its detail view? - objective-c

Question

I have a table view, and if a certain row is tapped, the detail view will show up. But how does the detail view know which row was tapped ?
So for instance, I have a MainController which displays names. If I tap "Johnny" The next screen should show a label with the string "Johnny". How would I do that ?
[EDIT - Added code]
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
ArticleView *article = [self.storyboard instantiateViewControllerWithIdentifier:#"ArticleView"];
[article.myLabel setText:#"random"];
[self.navigationController pushViewController:article animated:YES];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
NSDictionary *info = [json objectAtIndex:indexPath.row];
cell.textLabel.text = [info objectForKey:#"username"];
cell.textLabel.backgroundColor = nil;
cell.textLabel.textColor = [UIColor whiteColor];
cell.detailTextLabel.backgroundColor = nil;
cell.detailTextLabel.textColor = [UIColor whiteColor];
cell.detailTextLabel.text = [info objectForKey:#"user_pic"];
// Configure the cell...
return cell;
}
ArticleView.h
#interface ArticleView : UIViewController
#property (weak, nonatomic) IBOutlet UILabel *myLabel;
#end
ArticleView.m
-> Synthesizing properties

Answer 1

You could pass a object (i.e. the String Jonny) to the detail view controller as a property.
#interface ArticleViewController : UIViewController
#property (retain) ArticleView *articleView;
#end
//Don't forget to synthesize name
in the tableview controller
-(void)tableView:(UITableView *)tableview didSelectRowAtIndexPath:(NSIndexPath)indexPath
{
NSDictionary *info = [json objectAtIndex:indexPath.row];
ArticleViewController *articleViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"ArticleViewController"];
articleViewController.articleView = articleView;
[self.navigationController pushViewController: articleViewController animated:YES];
}

Answer 2

the table view delegate has the method tableView:didSelectRowAtIndexPath:, in this method you present your detail view so you know which row was selected from the indexPath parameter and can pass any info you need when you create the new view controller

Answer 3

Assuming you're talking iPhone here, I would have a property name on my detail view:
#propery (nonatomic, retain) NSString * name;
and an init method as follows:
- (id) initWithName: (NSString *) name
{
self = [super initWithNibName: #"<view-controller-nib-name>" bundle: nil];
if (self) {
self.name = name;
}
return self;
}
and then set name label in viewDidLoad
In the tableView:didSelectRowAtIndexPath: method, get the name referenced by the index path, create and init a detail view controller using initWithName:, then push on the nav stack.