tableView not updating in iphone - iphone

Question

I am developing an app which is similar to the settings app in iphone.
In my first VC i have a 4 rows upon selection it takes to the second VC. my second VC displays list of items. Once the user selected, the selected text should be displayed on the firstVC adjacent to the one selected.
How to achieve it with the help of dictionary objects or in other way.!Thanks in advance...

Answer 1

I did a similar task a few days back and here is how I accomplished that. Note, there might be many alternatives to achieving what you want.
KeyPoint: UITableView is dependent upon its DataSource (array or dictionary) for its data to be displayed in cell as well as number of sections and rows per section.
Now, initially your DataSource has values that are displayed as default. Upon tapping the row, initialize and push the 2ndViewController on navigation stack. In this 2ndViewController, you must somehow update the 1stViewController's DataSource (replacing original values).
Approach 1
You can use Protocols & Delegates
Create a protocol as following.
#protocol MyTableDelegate
- (void) dismissWithData:(NSString*)data;
Create a delegate reference in 2ndViewController, Call that delegate method and pass the selected data
#interface 2ndViewController : UIViewController
#property (assign) id<MyTableDelegate> delegate;
#property (assign) NSIndexPath *ip;
// Also synthesize it
#implementation 2ndViewController
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[self.delegate dismissWithData:#"Second Table Selection"];
[self.navigationController popViewControllerAnimated:YES];
}
Now in 1stViewController, implement the TableView & Protocol Method
#interface 1stViewController : UIViewController <MyTableDelegate>
#implementation 1stViewController
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
2ndViewController *controller = [[2ndViewController alloc] initWithNib....];
// Set the Delegate to Self
controller.delegate = self;
self.ip = indexPath;
// Push Controller on to Navigation Stack
}
- (void) dismissWithData: (NSString*) data
{
// We Will Store NSIndexPath ip in didSelectRowAtIndex method
// Use the ip to get the Appropriate index of DataSource Array
// And replace it with incoming data // Reload TableView
[self.dataSource replaceObjectAtIndex:[ip row] withObject:data];
[self.tableView reloadData];
}
Approach 2
You could also pass the data source to 2ndViewController in the didSelectRowAtIndexPath method..
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
2ndViewController *controller = [[2ndViewController alloc] initWithNib....];
controller.dataArray = self.dataSource;
// Push Controller on to Stack
}
Then in the same didSelectRowAtIndexPath method of 2ndViewController, update the data source, and call
[self.navigationController popViewControllerAnimated:YES];
also, you need to reload your tableview in 1stController's ViewWillAppear method
- (void)ViewWillAppear:(BOOL)animated
{
[self.tableView reloadData];
[super ViewWillAppear:animated];
}

Answer 2

I think you need to call [self.tableView reloadData] in viewDidAppear. If possible do go through this link Reload UITableView when navigating back?

Answer 3

The array that you are using in your first VC. Pass that array to the second VC, update it there in the secondVC class and write this statement "[firstVC.tableView reloadData]" in the viewWillAppear method of your firstVC class.
This will update your array of firstVC class in secondVC class when user selects anything in secondVC class, and than when user naivgates back table view of firstVC is reloaded. So that the update array is reflected in table view.