Using Xcode 4.3.1, ipad app for iOS 5.1, no core-data
On my storyboard I have a master-detail project. The master obviously has a TableView, and that works fine: by selecting an item in the master tableview my detail data is set in the detail view controller by the template code call setDetailItem (which I call from 'didSelectRowAtIndexPath'). That works fine.
My DetailView/Scene contains (another) UITableView (amongst other, also some TextFields etc.)
This UITAbleView's datasource and delegate are connected to the detail view controller.
In the detail viewcontroller's interface file I adde the protocols UITableViewDataSource and UITableViewDelegate (next to the pre-configured UISplitViewControllerDelegate).
I implemented the methods numberOfSectionsInTableView, numberOfRowsInSection, cellForRowAtIndexPath, didSelectRowAtIndexPath methods in the detail view controller.
However, these are only called when the master tableview's list is build up, not when I select an item in the master list/tableview. When I select an item in the master list/tableview the detail data get's set in the detail viewcontroller, but for instance the 'cellForRowAtIndexPath' in the detail controller is never called, and the detail TableView is not updated/initialised. (The textfield in the detail view however is loaded with the correct data).
I guess I am missing something. Do I have to give the tableview a kick at the point I prepared it's data? And if so, how...? The tableview itself is not connected to an outlet or action, should it?
Thanks!
You need to implement a custom delegate (one-to-one communication) from RootView to Detailview.
Like the following,
Implement the Delegate in RootView,
#protocol RootViewControllerDelegate <NSObject>
-(void)didchangeSelectionInRootViewList:(id)toItem;
#end
And call the delegate when needed as (in your case on table view didSelectRowAtIndexPath),
//a delegete need in caes of splitview to refresh the detailview.
-(void)callDelegate:(id)sender {
if(self.delegate && [self.delegate respondsToSelector:#selector(didchangeSelectionInRootViewList:)]) {
[self.delegate didchangeSelectionInRootViewList:sender];
}
}
And don't forgot to set the delegate in Rootview as detailview while creating splitview controller.
And also catch the delegate in Detailview and reload the TableView with sufficient data to load.
thanks,
Naveen Shan
Related
I'm having a little issue with an app I've completed. The problem is with a search view controller presented modally.
I have a search button that when tapped presents the SearchViewController modally.
I have 3 different controllers it can be presented from.
MainViewController > CollectionViewController > DetailViewController
This is actually how the controllers are in the hierarchy.
The results are always displayed on the collection view controller. Basically the collection view is refreshed and the remaining cells show are the result of the search.
Searching from collection view controller:
In the collection view controller, when the search is tapped. The search view controller is presented modally. Search text is entered and a list of matches is shown. When a row is tapped then the search view controller is dismissed and notifies the collection view controller using delegation the collection view is them refreshed with the results.
Searching from detail view controller:
In the detail view controller, when the search is tapped. The detail view controller is popped off the stack revealing the collection view controller. I use delegation to notify the collection view controller that the detail view controller was popped of the stack after the tap of a search button. Immediately the search view controller is opened making it possible to search as if we originally presented the search view controller from the collection view controller.
My issue arises when trying to search from my main view controller. Right now things are working but it doesn't have a very professional feel to it. Let me explain.
To get search working from my main view controller I use delegation. So in the method connected to the search button I perform this segue:
- (void)searchButtonTapped
{
[self performSegueWithIdentifier:#"garmentsCollectionSegue" sender:nil];
}
The protocol is defined in my interface file:
#class VAGMainTableViewViewController;
#protocol VAGMainTableViewControllerDelegate <NSObject>
- (void)mainTableViewControllerDisappearedwithTitleForObject:(NSString *)titleString;
- (void)searchButtonOnMainTableViewControllerTapped;
#end
#interface VAGMainTableViewController : UITableViewController
#property (nonatomic, weak) id<VAGMainTableViewControllerDelegate> aDelegate;
In my preparation before segue I have this:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
[self setADelegate: [segue destinationViewController]];
[[self aDelegate] searchButtonOnMainTableViewControllerTapped];
}
Here I set the delegate and also make a call to the delegate method, making the collection view controller aware of the button tap in my main view controller.
Finally in my collection view controller when the tap is detected a call to the method that presents the search view controller modally is made. Search view controller is presented.
In collection view controller
- (void)searchButtonOnMainTableViewControllerTapped
{
[self searchButtonTapped];
}
- (void)searchButtonTapped
{
VAGSearchViewController *svc = [[self storyboard] instantiateViewControllerWithIdentifier:#"searchPageSB"];
svc.delegate = self;
[self presentViewController:svc animated:NO completion:nil];
}
The search view controller notifies the collection view controller it was dismissed using delegation. This is when the querying and refresh of the collection view controller is done and the result of the search is shown.
- (void)searchViewControllerDismissed:(VAGSearchViewController*)searchViewController withTitleForObject:(NSString *)titleString
{
_searchTitleString = titleString;
[self setObjects:nil];
[self performQuery];
}
Ok so this works but it doesn't look professional because for a split second after the push to the collection view controller from the main view controller the collection view is shown before the search view controller is presented.
The feel I'm aiming for is a snappy one. So I'd prefer if the search view controller would be presented instantly.
Hopefully my detailed post give you an idea of what I'm doing.
There is a much more efficient way to do this. The problem is I can't figure it out.
Would appreciate some help
Thanks for your patience
You can do one thing did not push Collection view controller when search button is tapped.
After pushing modalviewControler if search done then you Call the delegate in MainviewController and Then push collection Viewcontroller with no animation in DelegateMethod. its look what you want
I want to make my code more modular and flexible.
So rather than setting a the tableViewDelegate as the UIViewController, I have a subclass of UITableViewController as the tableView data source and delegate.
Basically, the original UIViewController provides the view for the subclass of UITableViewController.
That way similar tables can be used by several UIViewController's subclasses.
In some cases, UIViewController's provide the tableView and I just switch the tableView delegate at run time.
Works well.
Here is the code for BGTableViewDelegateMother that inherits from UITableViewController (that inherits from UIViewController.
#implementation BGTableViewDelegateMother
-(void) setDelegate:(id<BGTableViewDelegateMother>)delegate
{
_delegate=delegate;
self.view = self.delegate.tvDelegated; //So that viewWillAppear would work fine
[self view]; //load the view view didload is not called either
self.delegate.tvDelegated.delegate =self;
self.delegate.tvDelegated.dataSource=self;
}
Okay. The UITableViewController.view is used for one thing. Now that it points to the correct tableView, I expect viewWillAppear to be called. It's not
I think everytime the tableView will be shown, I should at least reloadData
-(void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];//never called
[self.delegate.tvDelegated reloadData];
}
This code never called. Even though the view will indeed appear. Why?
viewDidLoad is also never called.
Make the table view controller a child view controller of your view controller while its view is linked (and it is the data source) and could be on screen. This tells the view controller hierarchy that the table view needs to know about the appearance callbacks.
Is it possible to embed (add as subview) a UITableViewController into another View Controller programmatically? I found a few answers here on StackOverflow but none worked for me with ARC and iOS6 SDK.
I know you can do this easily with Navigation and TabBar controllers but I am more curious about adding tableviews to a regular View controller. I need my tableview to occupy the lower part of the available screen space (I need the rest for other purposes, for which neither tab nor navigation types are suitable).
When I tried to do it, however, it did not work. I instantiated a subclassed UITableViewController, but when I added it to my self.view as a subview, the compiler said I tried to use "incompatible pointer types." Not only that, my instantiated UITableViewController does not have a .frame property, so I cannot set it dimensions, which would be the whole point of this exercise.
Building upon ogres answer, you should add the tableViewController's view as a subview, but it is not everything. The tableViewController is a viewController and it needs to know its parent and its children, to do its viewController-job correctly. I do not know any details here, but there is an entire talk about this from WWDC 2011 called "Implementing UIViewController Containment".
One problem I have experienced when only adding the view as a subview is that target actions don't seem to work. Tapping a UIButton or similar causes either a EXC_BAD_ACCESS or a unrecognized selector sent to instance.
So I recommend that you do something like this:
UIViewController *vc = //Your tableViewController
[self addChildViewController:vc]; //Important
[self.view addSubview:vc.view];
//If you want to set the frame, set the frame of the tableViewController's view
vc.view.frame = ...
yes , you can use tableview in another view without any problems
UITableViewController, but when I added it to my self.view as a subview
are you trying to add viewcontroller as subview or its view ? ( viewcontroller.view )
UITableViewController does not have a .frame property,
of course it does not have .frame property , it is a view CONTROLLER , you should see .view.frame
I have a UISplitViewController with the master view set up like this:
UITabBarController
Tab1:
UINavigationController -> UIViewController -> UIViewController
Tab2:
UINavigationController -> UIViewController
Each of the UIViewControllers is a table view, and when the user chooses a row in the last one, an image is shown in the detail view, which contains a UIScrollView.
The tab bar Controller is the UISplitViewControllerDelegate and handles putting up the button on a toolbar at the top of the scroll view.
The problem is, I want to add code to dismiss the popover when the user makes their choice. The pointer to the popover has to be saved in the tab bar controller when the button goes up, and then used to dismiss the popover several view controllers down the line when the user makes their final selection. There doesn't seem to be any way for the view controller that needs that pointer to get at it, without doing something gross like storing it in the App Delegate.
I don't see other people asking this question, which leads me to believe that I've once again overlooked something simple. Please enlighten me!
It sounds like your tab bar controller is already a subclass of UITabBarController, which means that you've already got some custom code in there. I would suggest that the tab bar controller is the primary owner of the popover, and it is the table view controller's responsibility to simply notify the tab bar controller that a selection has been made. The tab bar controller can respond to that message by dismissing the popover. You can take advantage of the fact that UIViewController already has a method for accessing the tab bar controller that contains a given controller.
So it would look something like this:
#interface MyTabBarController : UITabBarController
- (void)itemWasSelected;
#end
#implementation MyTabBarController {
UIPopoverController *popover;
}
- (void)itemWasSelected {
[popover dismissPopoverControllerAnimated:YES];
}
#end
//////////////
#implementation TableController
- (void)tableView:(UITableView *)tv didSelectRowAtIndexPath:(NSIndexPath *)path {
// Do whatever else you want to do
MyTabBarController *tabController = (MyTabBarController *)self.tabBarController;
[tabController itemWasSelected];
}
With this solution, the table controller doesn't have to know anything about the popover; it just has to know that it's going to be presented inside a MyTabBarController, which seems a reasonable thing for it to know.
You could create a singleton class to track your popover status and then make it available to all classes equally and easily. That way it could easily be updated and accessed from any code without having to go straight to overburdening the app delegate even though thats basically the same idea but a bit cleaner in its own singleton.
This one is probably something simple, still learning the ins-and-outs on this but I've run out of searches for this one with no available answer.
I've got a UIViewController with several elements displayed on it, one such element is a UITableView. The UITableView has it's own class and is allocated in the UIViewControllers viewWillAppear
- (void)viewWillAppear:(BOOL)animated
{
UITableView *insideTableView = [[UITableView alloc] init];
tableView.delegate = insideTableView;
tableView.dataSource = insideTableView;
}
Everything is working fine in regards to the tableview. Today I am experimenting with a few additions, one of which is a new view popup on cell selection within that tableview.
Inside my TableView Class, I have the following:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"Cell Pressed, Present View");
PopupView *popupView = [[PopupView alloc] initWithNibName:#"PopupView" bundle:nil];
popupView.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:popupView animated:YES];
}
Now it gets called fine, verified by the NSLog, however the view doesn't appear. I know the problem is related to the fact that I want PopUp to appear over the TableViews Parent rather than itself.
I'm just not sure how to properly call it in this instance.
The delegate is a UIViewController which doesn't have its view property set, which is why presentModalViewController:: doesn't work.
You need the view controller containing the table view to present the modal view controllers, but note that that view controller is not the parent of the table view delegate. This is because you have no view controller hierarchy in place.
The easiest way to fix this is to put those methods inside the view controller whose view contains the table view. Alternatively the table view delegate needs to hold a reference to the view controller so it can call presentModalViewController:: on it.
The latter approach can lead to retain cycle, so you have to use a non-retaining reference. The nicest implementation is the delegate pattern.
Also, you don't want to do the instantiation in viewWillAppear: because that can be called multiple times during the lifecycle of a view controller. Put the code in viewDidLoad and balance it in dealloc. Right now you are leaking memory every time your view appears, which when your modal view controller is working will be every time the modal view controller is presented and dismissed.