I am using Storyboard in my app and I want to pass data from one view to another view.
Instead of using segues I am using instantiateViewControllerWithIdentifier. In this case I am instantiate from my first TableViewController to a NavigationController which has a second TableViewController attached because I need the navigation in the second TableViewController. Now I want to pass data from my first TableviewController, depending which row was clicked, to my second TableviewController. In this case newTopViewController would be my NavigationController but my problem is now how to pass data from firstTableViewController to the secondTableviewController.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *identifier = [NSString stringWithFormat:#"%#Top", [menuArray objectAtIndex:indexPath.row]];
UIViewController *newTopViewController = [self.storyboard instantiateViewControllerWithIdentifier:identifier];
}
If you instantiate a navigationController, you can use the viewControllers property to get the inner viewController of the navigation controller.
Something like this:
UINavigationController *navigationController = [self.storyboard instantiateViewControllerWithIdentifier:identifier];
MBFancyViewController *viewController = navigationController.viewControllers[0];
// setup "inner" view controller
viewController.foo = bar;
[self presentViewController:navigationController animated:YES completion:nil];
newTopViewController.anyVariableToShow= anyVariableToSend;
I do this pretty often on a few of my apps...
//Create new VC
CookViewController *detailViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"CookVC"];
//Set recipe
[detailViewController setRecipe:recipe];
//Pop over VC (can be pushed with a nav controller)
[self presentPopupViewController:detailViewController animationType:MJPopupViewAnimationFade];
If you aren't using a navigation controller or segues, then I think you need to reconsider your app design.
Actually it's not just a data pass problem as this is a program control and data transfer question together.
Even you would have to rethink about your app's concept, as you'd like to use storyboard without the meaning of storyboard, it's up to you and I hope you have good reason to do what you do.
So when you decided not to use segue you lost the new and comfortable way of instantiating a new controller and transferring data with it and you have to do the transfer of control and the data in two distinct steps. When you instantiate another scene in storyboard (like you do with instantiateViewControllerWithIdentifier:) you just instantiated a new controller and transferred the control but not the data. Just think about it as you instantiated a new controller from a xib in an old way (so you have to use initWithCoder: or awakeFromNib in the second view controller as the storyboard will not call initWithName:bundle:), but did not do anything more.
So you will have a new controller (it named in the identity part of the second storyboard) which is hanging in the universe without any relationship or connection with anything else (as the storyboard picture illustrates it nicely) and you could do with it what you'd like.
So you'd like to do something and you need data from the previous storyboard (ViewController). What you need is making available those data to the second storyboard(ViewController), and as you know there are lot of solution for this which were available long time before even storyboard is existed.
So regarding your code, the "data transfer" is depending on your design, whether the two controllers are subclasses of each other or whatsoever...
If you don't like to deal with subclassing and like to decoupling them as much as possible, the best way just make a property of your data in the first controller and refer to them from the second (after importing the first's .h file) and just refer to it in it's viewDidLoad or in initWithCoder: or anywhere where you need them, as
secondViewControllerdata = firstViewControllerdata.thatDataProperty
Of course you can do the same in reverse and make a property of the second controller and refer to it in your first view controller.
You can define some parameter in UIViewController to receive data:
#property (assign) int param1;
#property (retain) NSMutableArray *param2;
and use below to pass the data:
[newTopViewController setParam1:XX];
[newTopViewController setParam2:XX];
Related
I have 2 view controllers . First one is UIview controller and second one is table view controller.
I want to send data 2nd (table view controller) to first(uiview Controller) after the selection of rows of 2nd view controller.
For this i have written a delegate protocol.
But my delegate protocol is not working...
I figured out the problem.The object of second view controller that i am creating.
address = [[second_viewcontroller alloc] init];
address.delegate = self;
is different from self of second_viewcontroller view controller page.
How to make this two same.
self = [[second_viewcontroller alloc] init];
your problem my delegate protocol is not working... I figured out the problem.The object of second view controller that I am creating. address=[[second_viewcontroller alloc]init]; address.delegate=self; is different from self of second_viewcontroller view controller page.
It's clear say that way you create the second_viewcontroller object is not right.
You have to create the object from ViewController storyboard identifier.
First give the Storyboard ID to ViewController from Storyboard.Follow this step to Giving the Storyboard ID.
Select the particular ViewController in Storyboard.
Go to IdentityInspector.
Under IdentityInspector, There is identity section and add the Storyboard ID In "Storyboard ID" Field.
Syntax For Creating a ViewController Object.
Second_viewController *aVC = [self.storyboard instantiateViewControllerWithIdentifier:#"Second_viewController"];
aVC.delegate = self;
I assume that you are calling the Second_ViewController from storyboard instead of doing programmatically.
In that case, the correct instance of Second_ViewController can be accessed in prepareForSegue. For that, you need to set a Storyboard segue identifier, eg "Second_ViewController"
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"Second_ViewController"]) {
SecondViewController *aSecVC = segue.destinationViewController;
// Register the Delegate to self.So when we call the delegate method from secondVC, SendMessage will be call of ViewController
aSecVC.delegate = self;
}
}
If you use alloc-init or instantiateViewControllerWithIdentifier, when you are using a storyboard push segue, it will create another instance.
Yes as your instantiating a new instance of the second view controller. From what I could make out from your question, I guess if you obtain the instance of your secondViewController from the Navigation Stack it should work
I created a sample project for you to get the basic knowledge of how to pass data backward using NSUserDefaults. try this in GitHub. hope this will help to you. project url Pass data backward using NSUserDefaults in Objective-C
In my app, I need to go to another UIViewController with a button click, but when I did it in the new UIViewController it displays only what I set programmatically.
I used:
NewSubject *NewS = [[NewSubject alloc] initWithNibName:nil bundle:nil];
[self presentViewController:NewS animated:YES completion:nil];
"NewSubject" is the UIViewController I need to go too, however I want the computer to display also the stuff I set by the Storyboard.
Have you set in the Storyboard, in the NewSubject View Controller, in the third tab (Show Identity Inspector) the StoryBoard ID?
You should set it to some name, such as "NewSubject" and use it as follow:
NewSubject *NewS = [self.storyboard instantiateViewControllerWithIdentifier:#"NewSubject"];
[self.navigationController pushViewController:NewS animated:YES];
I want the computer to display also the stuff I set by the Storyboard.
If you're using a storyboard, -initWithNibName:bundle: is the wrong method to use. You can use UIStoryboard's -instantiateViewControllerWithIdentifier: method to create a new view controller that's defined in a storyboard, but the more typical approach is to have your button trigger a segue between the two view controllers.
Try this:
While editing your storyboard, control-drag from your button to the new view controller. A popup menu should appear that lets you choose how you want to transition between the view controllers -- push (push the new controller onto the top of the navigation stack), modal (present the view controller modally), etc. Pick the appropriate one.
In simple cases, you're done -- there's no need to write any code just to get the transition to happen. The segue takes care of creating the new view controller and performing the transition for you. However, you often want to pass some data from the existing view controller to the new one. If that's the case, implement -prepareForSegue:sender: in the existing view controller -- this method gives you a chance to pass whatever data you need. It'll look something like this:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// It doesn't hurt to check that it's the segue that you expect
if ([segue.identifier isEqualToString:#"MySegueIdentifier"]) {
NewViewController *newVC = segue.destinationViewController;
// This is your chance to set properties or call methods to pass data to the new view controller
newVC.foo = self.foo;
newVC.bar = self.bar;
}
}
I want to send a UITableViewCell at indexPath.row from one controller to another. I can remove the row using removeObjectAtIndex, but unable to send the removed row into another controller.
I'm trying to store the removed row in an NSMutableArray in one controller, but don't know how to populate it in another controller.
Below is the code -
ViewController *view= [self.storyboard instantiateViewControllerWithIdentifier:#"ViewController"];
view.anotherviewArray= [self.arrayFromAFNetworking objectAtIndex:indexPath.row];
If anyone can give me an idea, it would be helpful.
I believe it's bad practice to retain UI elements and pass them around your app. You should instead have some kind of a model containing your data, and pass this model from one view controller to the other. I'd recommend checking out tableview frameworks such as the free Sensible TableView framework, as they do an excellent job of providing such a model for you automatically.
I personally think that it's wrong approach to pass UI object as parameter to another controller.
As I would do it is create some object that encapsulates data model from this cell and pass this object to another view controller.
#interface DataObject : NSObject
#property id field1;
#end
UI part of cell can be easily copied in Interface Builder, so I don't see problem in that. Probably it would be great to have cell class that could fill necessary field from the object with data. This class you can use in both view controller that have to show the same cell
#interface CustomTableViewCell : UITableViewCell
- (void)customizeCellWithDataObject:(DataObject *)dataObject;
#end
I hope it makes sense to you
Assuming that you DO want to set the other data source with only this row, you need to pass it as an array.
view.anotherviewArray= [NSArray arrayWithObject:[self.arrayFromAFNetworking objectAtIndex:indexPath.row]];
But it's hard to tell from the little code that you have provided. I assume that since you are instantiating the viewController you are also transitioning to it below the provided code. If you are trying to set the array for a viewController already presented, you need to access that one, not create another, perhaps by having saved a reference to it an ivar within the current viewController or another accessible class.
I would also not name a ViewController view, it is confusing to anyone reading the code later on.
Editing for my comment below about traversing the hierarchy. Here is some code that I used in one iPad project to return the final presented viewController. This method is in the appDelegate. It is somewhat specific to my project, where there is only one navigationController. But you can adapt it to yours. You would test for a viewController that is of the class of your target view controller.
- (UIViewController *)topViewController {
UIViewController *rootViewController = self.window.rootViewController;
UIViewController *topViewController = rootViewController.presentedViewController;
while (topViewController && topViewController.presentedViewController) {
topViewController = topViewController.presentedViewController;
if ([topViewController isKindOfClass:[UINavigationController class]]) {
UIViewController *presentedViewController = [(UINavigationController *) topViewController topViewController];
if (presentedViewController) {
topViewController = presentedViewController;
}
}
}
return topViewController;
}
The other approach is to set a property to it when it is created and presented. We don't have enough code to get a good idea of your app as a whole. Where are you creating the ViewController instance that you are displaying? By that I mean where you are calling a segue to it, or pushing it onto a navigationController or call presentViewController. Wherever that is, you need to set a property or ivar to it. Let's say that you use a property in your appDelegate as a very generic case.
In your MyAppDelegate.h file you have
#property(nonatomic,strong) ViewController *viewController;
Wherever you first create it you set that property
MyAppDelegate *appDelegate = (MyAppDelegate*)[[UIApplication sharedApplication] delegate];
appDelegate.viewController = [self.storyboard instantiateViewControllerWithIdentifier:#"ViewController"];
I now think you are trying to add this to a mutableArray in the other ViewController. Then replacing your code from the tableViewCell above you would use
MyAppDelegate appDelegate = (MyAppDelegate)[[UIApplication sharedApplication] delegate];
[appDelegate.viewController.mutableDataArray addObject:self.arrayFromAFNetworking objectAtIndex:indexPath.row];
[appDelegate.viewController.tableView reloadData];
I will say that it is not great practice to use the appDelegate for the property. But it is a generic answer that would work. It's best to put it in a class which is common to the viewControllers that you are passing data between. Perhaps a single parent which holds these two viewControllers?
I still haven't grasped this transfer with the structure below. I have read many posts, and have seen the same unanswered post by others, but no resolution.
I will try to simplify the question to make it easier for all.
The structure of the project is:
UITabbar with tab1 and tab2
Tab1 has a Nav controller-->ViewController1
Tab2 has a Nav controller -->ViewController2
In viewcontroller1 (tab1) I have object X.
In ViewCOntroller2 (tab2) I want to display object X.
Don't worry about displaying, that's the easy part.
Question: How do you pass object X from tab1 to tab2. (what is the general pattern).
If you want to do it using prepareForSegue, is this ok, or is there a better way.
If using prepareForSegue, where do you drag the segue to?
The tabbarcontroller
OR*****
2. to the second VC
Hopefully this is clear enough. With this in mind how would you perform the transfer?
Using the segue 1:
I tried doing this:
//(From View controller 1)
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"CreateObjectXToDisplayObjectX"])
ViewController2* vc2 = [[ViewController2 alloc] init];
UITabBarController* tbc = [segue destinationViewController];
vc2 = (ViewController2 *)[[tbc customizableViewControllers] objectAtIndex:1];
//Crash here with with [MainNavigationControllerDesign setViewController1Delegate:]: unrecognized selector sent to instance 0x1064ef70'
vc2.viewController1Delegate=self;
vc2.objectXAtViewController2 = _objectXFromViewController1;
}
}
So, how is this Object X transfer accomplished?
Thank you in advance
You don't want to use segues in this way. Segues always instantiate new controllers when you go to them, but you already have these controllers embedded in the tab bar controller. If you were setting this up in code, I would say use a delegate, but if you set this up in IB, it's hard to do that. From VC2, you can get a reference to VC1's navigation controller with self.tabBarController.viewControllers[0]. VC1 will be that navigation controller's topViewController, so, putting that together, and adding a cast, you can access VC1 like this:
ViewController1 *vc1 = (ViewController1 *)[self.tabBarController.viewControllers[0] topViewController];
Once you have that reference, you can access any of vc1's properties. Don't forget to import ViewController1.h into ViewController2's .m file.
I have a pretty simple question. Say you have 2 view controllers A and B. A is a UITableView with STATIC CELLS. That is A is built using storyboard objects only as opposed to programmatically. B is also a UITableView but built programmatically with DYNAMIC CELLS. So I wired up Segues (with identifiers set in the storyboard) from each cells in A to the B Tableview.
Now what I would like to have is to know which segue has been pushed when a row in A is selected. I know this can easily be done if I create the cells in view A programmatically and use the prepare/perform segue methods. But since the contents in A will never change, I do not want to go that route. Reason why I am trying to find out how to check which segue has been pushed when I select a given row in A. Ideally there would be some for of a method DIDPERFORMSEGUE: (Segue identifier) I could call from the B Viewcontroller.
Thanks very much for your help and suggestions.
In your "A" TableView, you should be able to peek at which row was poked, and then push that information to your "B" table. For example:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if([[segue identifier] isEqualToString:#"UITableView_B"]){
BTableViewController *vc = (BTableViewController *)[segue destinationViewController];
NSIndexPath *path;
path = [self.tableView indexPathForSelectedRow];
[vc setSelectedPath:path];
}
}
Hope that helps. Best of luck.
Edit: Probably obvious, but in the above "self.tableView" is an outlet pointing at the UITableView.
Update
Personally, I'd bite the bullet and make a class for "A", but in the interest of hacking - it should be possible to reach back and get data from the previous view. This is 'bad code' (imo) and assumes you're using a Navigation Controller - and that the previous view is an "A" table, etc... Without further ado - is should be possible to just do this:
NSArray * views = [self.navigationController viewControllers];
NSUInteger prevViewIndex = [views count] - 2;
UIViewController * previousView = [views objectAtIndex:prevViewIndex];
ATableViewController * aTableViewController = (ATableViewController *) previousView;
NSIndexPath *path = [aTableViewController.tableView indexPathForSelectedRow];
I can't say I've needed to do this myself, but if you really don't want to change the source view controller or if you have a frequent need to identify the segue from the destination view controller, one way to do it would be to create your own UIStoryboardSegue subclass. A segue already knows about the destination view controller, so it's a simple matter to give the destination a chance to inspect the segue. Something like this should do the trick:
#interface MyStoryboardSegue : UIStoryboardSegue
#end
#implementation MyStoryboardSegue
- (void)perform
{
[super perform]
if ([self.destinationViewController respondsToSelector:#selector(didPerformSegue:)]) {
[self.destinationViewController didPerformSegue:self];
}
}
#end
It's not a great solution if you're already using UIStoryboardSegue subclasses for other reasons. And in fact, I haven't even tested the code, so perhaps there are some snags I haven't thought of yet. The point, however, is that if you want a segue to notify the destination when it executes, you can probably arrange it.