Passing data from a dynamic table to a static table - ios

Question

I'm a newbie in IOS,
I've been strugling with passing data from child to parent tableview. I have defined the parent table view as static, four cells are connected to other table views. These tableviews has data i would like when selected to be passed to my static cell accordingly. I read a lot of solutions about passing data, using delegates and segue but none of them seem to be working for me. i.e. a repeat cell in static table view has two labels and the UILabel Repeat, I don't want that to change and repeatDetail this is the one that when a disclosure indicator is triggered and a new tableview is presented with the data to choose to be able when i click back button to have the seleted data in my repeatDetail Label. My static table is embeded in Navigation controller using storyboard. I would like when data is selected in FirstChildViewController to modify selected data i.e. Monday to Mon in RootViewController. However in my code after selecing data in child checkmark is there but as soon
as I move back to RootVC nothing is showing,and when i go back to Child no selction is howing either.
1. Save the selected Data in Child, only change when there is new selection
2. Use short week names when sending to RootVC
3. repeatDetail to have the selected data
Without writting too much let me show what i have done.
in RootViewController.h // RootViewController is static
#import "FirstChildViewController"
#interface RootViewController: UITableViewController <repeatProtocol> //RootViewController COnfirms to the delegate
#property repeat, repeatDetail;
#end
next on my RootViewController.m
#implementaion RootViewController
#sysnthesis repeat,repeatDetail;
- (void) viewDidload
{
repeat.text = #"Repeat"
repeatDetail= //not show how call this label from 1stViewController
}
-(void) selectedValue:(NSString *)string //protocol method
{
FirstChildViewController *RVC =[[FirstChildViewController alloc] init];
RVC.delegate =self;
[self selectedValue:string]; //This part confuses me, i know i have to implement the delegate method but not sure if i implement it correctly.
}
-(void) didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
}
in FirstChildViewController.h
#class FirstChildViewController
#protocol repeatProtocol <NSObject>
#required
-(void) selectedValue:(NSString *)string;
#end
#interface FirstChildViewController: UITableViewController
{
NSArray *tableData;
id <repeatProtocol > repeatDelegate;
NSString *selectedDay;
}
#property (retain) id <repeatProtocol> repeatDelegate;
in FirstChildViewController.m
#synthesize tableData;
#synthesize repeatDelegate;
- (void) viewDidLoad
{
[super viewDidLoad]
tableData= [NSArray alloc] initWithArrays:#"Sunday",#"Monday",#"Tuesday",#"Wednesday",#"Thursday",#"Friday",#"Saturday";
}
- (int)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 7;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"RepeatCell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"RepeatCell"];
}
cell.textLabel.text = [tableData objectAtIndex:indexPath.row]//strings from an array here;
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = {tableView cellForRowAtIndexPath:indexPath];
cell.accessaryType = UITableViewCellAccessaryCheckMark;
[tableView deselectRowAtIndexPath:indexPath animated:YES];
if([self.delegate respondsToSelector:#selector(selectedValue:)])
{
[self.myDelegate selectedValue:selectedDay];
NSLog(#"string passed");
}
[self dismissViewControllerAnimated:YES completion:nil];
NSLog(#"FirstChildViewController dismissed");
}
#end

Answer 1

It's a little hard to sort out what's happening from your description; so I'll restate what I think the issue is.
You have a UITableView that displays something like settings that you which to modify in a series of distal view controllers. But you're unsure of what mechanism to use when returning that data to the static table view. Basically, you want to capture that data when the distal controller finishes. I won't deal with how you're displaying it in the root view controller, because it's unclear from your code sample.
Nonetheless, I'd favor not using a formal delegate protocol at all. It's just one datum going back - so a protocol seems like a wasted formality. I'd use a completion block.
So your FirstViewController interface could look like
typedef void(^WeekdayCompletionBlock)(NSString *dayName);
#interface FirstViewController : UIViewController
#property (nonatomic, strong) WeekdayCompletionBlock completionBlock;
#end
When you instantiate your FirstViewController, just provide it with a completion block. Since I think you are using Storyboards, you'd do this in prepareForSegue: method of your RootViewController.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
UIViewController *destinationController = segue.destinationViewController;
if( [destinationController isKindOfClass:[FirstViewController class]] ) {
[(FirstViewController *)destinationController setCompletionBlock:^(NSString *returnString){
// do something here with your string
// maybe you must reload your table
// it depends on where your returning data needs to display
}];
}
}
Finally, you need to execute that block when the user passes control back to the RootViewController. For example, is there a Save button or the like? There you would just execute the completion block, e.g. self.completionBlock(myNewDayOfWeekString)

Answer 2

Alternatively, you can create a global NSString in rootVC.h:
NSString *returnString;
Include rootVC.h in firstVC.h if you haven't already done that. This allows returnString to be accessible from firstVC.m:
#import "rootVC.h"
You can assign returnString in firstVC.m:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
...
returnString = <selected value>;
}
And show the returnString in rootVC.m below as NSBum pointed out:
-(void) viewDidload
{
repeat.text = #"Repeat";
repeatDetail.text = returnString;
}