iOS How to access an instance of a viewcontroller

[LT21j]

I have a problem with an app I am creating. FYI I am a newbie and this is my first major project so I might be missing some basic mechanics/ information. But here it is, I am wondering how I can access the instance of the view controller thats created automatically in storyboard via segue. The basic design of the app is that I have a main view but then the user presses a button to go into an information view. This information view contains a table view which contains dynamic table cells. Each cell has a two labels and a button. The way I want to have it is when the user presses the button that I have connected to the custom table view cell class I want it to get the information and then segue to another view controller called schedule view. The problem I am having is that I don't know how to get the instance of of the information view that is automatically created. I'm trying to use the method [self performSegueWithIdentifier"toSchedule" sender: self];


Any help would be much appreciated.

[EDIT]
Here is my code:

#import "TeacherViewController.h"
#import "SchoolStaff.h"
#import "ClassViewCell.h"

@interface TeacherViewController ()

@end

@implementation TeacherViewController

-(IBAction)returned:(UIStoryboard *) segue
{
    //what the heck
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return _classList.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"classViewCell";
    ClassViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    int row = [indexPath row];
    cell.Period.text = _classList[row][0];
    cell.cName.text = _classList[row][1];
    return cell;
}
- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view
    _datTeacher = [[[SchoolStaff sharing]fList]objectAtIndex:2];
    
    _freePeriods.text = _datTeacher.freePeriods;
    _classesTaught.text = _datTeacher.classesTaught;
    _teacherName.text = _datTeacher.tname;
    _department.text = [[NSString alloc] initWithFormat:@"%@%@",_datTeacher.department, @" Department"];
    _wayToReach.text = _datTeacher.toReach;
    _funFact.text = _datTeacher.funFact;
    _room.text = _datTeacher.room;
    _teacherImage.image = [UIImage imageNamed: [[NSString alloc] initWithFormat:@"%@%@",_datTeacher.tname, @".TIF"]];
    _classList = _datTeacher.cList;

}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
	return YES;
}

-(void) segueMethod
{ 
    [self performSegueWithIdentifier:@"toSchedule" sender: self];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return @"Classes:";
}
@end

Here is code for the tableviewcellclass

@interface ClassViewCell : UITableViewCell
@property (strong, nonatomic) IBOutlet UILabel *Period;
@property (strong, nonatomic) IBOutlet UILabel *cName;
- (IBAction)buttonIsPressed:(id)sender;
//Want segue to take place^^
@end

 

[dejo]

You haven't really told us what the problem is, though. Are you getting warnings/errors/crashes? Something else? What's not working?

Also, what resources have you been using to become familiar with the fundamentals of Objective-C / iOS Programming. Please be specific.

 

[Duncan C]

I have a problem with an app I am creating. FYI I am a newbie and this is my first major project so I might be missing some basic mechanics/ information. But here it is, I am wondering how I can access the instance of the view controller thats created automatically in storyboard via segue. The basic design of the app is that I have a main view but then the user presses a button to go into an information view. This information view contains a table view which contains dynamic table cells. Each cell has a two labels and a button. The way I want to have it is when the user presses the button that I have connected to the custom table view cell class I want it to get the information and then segue to another view controller called schedule view. The problem I am having is that I don't know how to get the instance of of the information view that is automatically created. I'm trying to use the method [self performSegueWithIdentifier"toSchedule" sender: self];

Any help would be much appreciated.

Any time you invoke a segue, the system looks for a prepareForSegue:sender: method in the view controller that is triggering the segue.

If you implement that method, it gets called.

That method gets passed a pointer to the segue object. The segue object has properties for both the source and destination view controller. After invoking a segue, you can put code in your prepareForSegue:sender: method that gets the destination view controller and saves a pointer to it.

You can also set up the destination view controller to have a delegate property, and the invoking VC can set itself as the delegate of the invoked VC. This is documented in Apple's docs on segues.

 

[LT21j]

You haven't really told us what the problem is, though. Are you getting warnings/errors/crashes? Something else? What's not working?

Also, what resources have you been using to become familiar with the fundamentals of Objective-C / iOS Programming. Please be specific.

I am have been using various sources. Mostly the apple development API and a book called ios essentials. The reason I'm having trouble is I cannot say [self preformSegueWithIdentifier: @"toSchedule" sender: self] becuase this line takes place in the code of the class tableCellView in the method -(IBAction) buttonPressed: sender (id). So I need to replace the self with and instance of the containing class view controller.

 

[dejo]

...a book called ios essentials.

Can you be more specific? Normally when referencing a book, it's courteous to provide exact title, author, and edition (and chapter and page number, if applicable).

 

[Duncan C]

I am have been using various sources. Mostly the apple development API and a book called ios essentials. The reason I'm having trouble is I cannot say [self preformSegueWithIdentifier: @"toSchedule" sender: self] becuase this line takes place in the code of the class tableCellView in the method -(IBAction) buttonPressed: sender (id). So I need to replace the self with and instance of the containing class view controller.

You need to post an explanation of how your code is structured, and post the code. Are you using storyboards or XIB files? How are you managing your table view? Which object is it's delegate and data source? How are cells created?

It sounds like you have a custom table view cell class, and controls in the cells are triggering actions in the cell object instead of in the view controller.

Is that right?

 

[LT21j]

Can you be more specific? Normally when referencing a book, it's courteous to provide exact title, author, and edition (and chapter and page number, if applicable).

The book is called IPhone IOS 6 Development Essentials by Neil Smyth. But the project I am trying to make is not discussed in the book.

 

[LT21j]

You need to post an explanation of how your code is structured, and post the code. Are you using storyboards or XIB files? How are you managing your table view? Which object is it's delegate and data source? How are cells created?

It sounds like you have a custom table view cell class, and controls in the cells are triggering actions in the cell object instead of in the view controller.

Is that right?

I posted some of the code above. Is that enough?

 

[Duncan C]

I posted some of the code above. Is that enough?

Ok, I'm right that you have a custom cell class.

Here's a way to handle it.

Give your custom cell class a delegate property.

Define a protocol that your cell uses to notify it's delegate (the view controller) about button taps. Create a method

- (void) cell:(UITableViewCell*) cell
  buttonTappedWithIdentifier: (NSString *) identifier;

Then have the buttons in your table view invoke action methods that send a notification to the delegate about which cell was tapped, and a code the delegate can use to figure out what action should be performed.

In the view controller implementation of that method, you can query the table view for the index path of the cell (using the table view method indexPathForCell). Then you can use the identifier code to figure out what to do with the button tap.

In your case, you could have your cell button action send a segue identifier to the delegate (the view controller) and invoke that segue. Then in prepareForSegue you could pass in the indexPath of the cell that was tapped.

 

[MattInOz]

In that case how does tapping the button differ from tapping the cell and reacting to that cell selection?

Couldn't you use the tableview delegate methods:-
– tableView:didSelectRowAtIndexPath:
or if you want two different behaviours
– tableView:accessoryButtonTappedForRowWithIndexPath:

Presenting your new view from one of those.

Your TableviewController (which is normally the delegate) will have a link to the navigation controller it lives within, making it easy to add a new view to the navigation stack. Also avoids the cells from having links back up the tree.

 

[dejo]

The book is called IPhone IOS 6 Development Essentials by Neil Smyth. But the project I am trying to make is not discussed in the book.

Thanks for the clarification.

 

[dejo]

LT21j, I see you edited your original post to include the code. I would like to ask you two things:

1. Please post the code as a followup rather than editing the original post, to help preserve the conversation flow of the thread
2. Please use

    tags when posting code snippets to prevent formatting side-effects. I have taken the liberty of editing your original post to use them.
   [/LIST]

 

[LT21j]

LT21j, I see you edited your original post to include the code. I would like to ask you two things:

1. Please post the code as a followup rather than editing the original post, to help preserve the conversation flow of the thread
2. Please use

    tags when posting code snippets to prevent formatting side-effects. I have taken the liberty of editing your original post to use them.
   [/LIST][/QUOTE]
   
   Oh okay. Thank you for the help. I will do that in the future from now on.