I have a mainwindow.xib file with a UITabBarController as the base view controller of the app. So inside the UITabBarController I've added about 10 sub UIViewController objects as tabs. Most of them are just a UITableViewController subclass or a UINavigationController containing a UITableViewController subclass.
In this design, each UIViewController is fully loaded on app startup, including calling the viewDidLoad method of each view controller. Is there any way to get around that? Since the view controllers are just UITableViewControllers with no other outlets, it seems excessive to create a NIB for each tab (which I assume would allow the viewDidLoad to only get called when the user first switches to the tab? Or am I wrong on that?)
Anyway, my question mainly, is: how is it conventionally done? If you have 10 different view controllers on one UITabBarController, do you put them all in mainwindow.xib? If so, should each have its own NIB, and if not, where do you put them, and how do you add them to the tab bar?
What you want to do is to define the UIViewController views in a different xib file for each view - the reason they all get instantiated is that when the xib loads, all objects held in the xib load - and that means all your views and view controllers since you have defined them there.
In MainWindow.xib where you have the tab bar defined, you can still set within each tab the view controller type that will be called and also the XIB file to use for that type (create a new project with the "TabBar application" template and the second default view will be like this).
Then as you press tabs the view controllers will be instantiated from the different XIB files you have defined.
Note that this means if you are using IB to add buttons to the navigation bar, you have to do that back in the TabBar xib and not in the xib you use to define the view. You can still link actions to the view controller definition within the tab.
The way Apple suggests doing it for pure NIB files is how you say: Each sub-view in its own NIB file.
Instead of doing this, I would create the UITabBarController programmatically. That way you can define all your simple views in code, and still load complex views from NIB files.
Personally, I prefer creating as many of my views programatically as possible. The compiled code has a smaller footprint than the NIB files and I feel like I have more control. I mostly use Interface Builder to mock up applications.
Related
I have an WizardSequenceViewController with an IBOutlet WizardView *_wizardView. In many WizardSequenceViewController.xib file I have the view outlet connected to the File's Owner - WizardSequenceViewController. I have a subview of that view defined with the class attribute set to WizardView. I have connected that WizardView to the outlet in the File's Owner. Finally, in my WizardView.xib I have a UILabel that I have placed in the file to test if the view is being rendered. When I select the WizardSequenceViewController from my tab bar, I see the superview view but not the subview _wizardView. When I set a breakpoint in my -(id)initWithCoder method in my WizardView.m file I see it stop there, so I know that it is calling that initializer (and thus it should be using the xib to load that file). I have tried many iterations and variations to get this thing to work but I can't and I am going crazy. Does anybody have any ideas?
From Apple doc "View Controller Basics, About Custom View Controllers":
The one-to-one correspondence between a view controller and the views in its view hierarchy is the key design consideration. You should not use multiple custom view controllers to manage different portions of the same view hierarchy. Similarly, you should not use a single custom view controller object to manage multiple screens worth of content.
Note: If you want to divide a view hierarchy into multiple subareas and manage each one separately, use generic controller objects (custom objects descending from NSObject) instead of view controller objects to manage each subarea. Then use a single view controller object to manage the generic controller objects.
Maybe you can't do a view-and-subview outlet setup in a view controller. And I'm not sure assigning the subview outlet to a separate NSObject subclass would work either, because how would you present it? Could you write your subview programmatically, using initWithFrame and addSubview, instead of making it an outlet? Or, if you really want to set it up graphically, could you assign it to a separate view controller as owner? Then the top view controller will call presentModal on the sub view controller. Or, if all you need is a UILabel as a subview, just add the label to the main view?
Even I faced a similar issue. But got it resolved by following steps given in the following link. Hope it helps.
http://blog.yangmeyer.de/blog/2012/07/09/an-update-on-nested-nib-loading
I have created Storyboard with several views calling each other, now I need to create the code
I notice that XCode didn't created .h and .m controller files for each View from storyboard.
Should I create them manually?
Should I keep only one controller? (or few depending of separation of concerns on MVC)
Is there a pattern for developing this?
thanks
The usual approach is one view controller pr. screen full of content. You can imagine having one view controller for a tableview, with any sort of content, and then another view controller that presents that content in a new screen full of content if a row is pressed.
Normally when you have subviews inside of your view controllers, you wire them up in interfacebuilder. Then for instance if you want to populate a view that has a uiimageview and a uiactivityindicatorview inside it, you can control their behavior and how their populated from the view controllers code. You could also if you want something very generic and you feel that one view will probably take up a lot of code in your view controller, create a uiview subclass for it, and then set the class in interface builder.
Did this help? Please let me know if you need more clarification.
It's entirely up to you whether you have a ViewController for each view. If you have many views I would recommend it. Even if you have 2 or 3 views you probably still should. Things can get really confusing when each view has a different task but all have similar IBOutlets.
TLDR; Personally, I would say it was good practice to have a ViewController for each view if each view has a separate task.
I want to use generally the old .xib files in my iPhone application. But when it comes to tableViewController storyboard is a lot more convenient in order to make custom cells etc. Is it possible to make a .xib based application and in the middle of it, to use a storyboard for a UITableViewController and its DetailedViewController only?
You can use a storyboard for any part of a program. Storyboards are not an all or nothing concept. You can have just one view controller in a storyboard, or a small network that just represents a subsection of your app.
To use just one view controller from a storyboard:
Add a new storyboard to your existing project.
Add a single view controller to the storyboard.
Assign an identifier to the view controller in the inspector.
Use the UIStoryboard class to load the storyboard resource
Use -[UIStoryboard instantiateViewControllerWithIdentifier:] to create a new instance of that view controller.
Install the view controller some place in your app by doing something like pushing it on to a navigation controller, or run it modally.
Both can work fine together (Storyboards and Nib files). In the TVC that is part of your storyboard, just instantiate the destination VC in code and use the usual initWithNibName method to load the nib file.
You can add a storyboard to any project, but the point of storyboards is to centralize your XIB files into one location rather than having 10 XIB files you can have 1 .storyboard file that contains 10 scenes representing your views. This shows your connections to other scenes, and you can manage all the seques and transitions of each scene. So is it possible, yes you could add a storyboard to your project, but I would recommend you design you entire application in a storyboard if you want to use them.
In a navigation based application, when I want to create and use other uiviews and uitableviews I need to create their controller and views. in an example I saw that I can simply create a new controller with .xib file, design it, and just call that xib file from my navigationcontroller.
In another example, some stuff was going on also in the mainwindow.xib and some new controllers and navigation items were added from the mainwindow.xib.
What is the difference between these methods? when and why I should need to open and edit the mainwindow.xib file to add a controller?
The mainwindow.xib is your UIWindow component which you can see as a representation of your iphone screen, it will always be there no matter what. In your examples when you are showing your view controller dirrctly that is because the controller is already a subview of your UIWindow which is the mainwindow.xib in the Interface Builder.
There really is no difference between the 2 methods, in the first one you are adding your controller as a subview progrmatically using:
[window addsubview:mynavcontroller]
And in the second one youbare doing it thru interface builder, you may use whichever method you feel more comfortable with.
You do not really need a controller to show a view, however they can be handy if you want to do any extra stuff such as rotating your view or loading certain data when the view is loading. That being said you could add your view as a subview of your window and it would still work.
I'm having a problem setting a View Controller nib's default View Outlet in Interface Builder. Here's my setup:
I have a TabBar based application where I load a Navigation Controller as a modal view...
MyNavCtrlrSubClass *menu = [[MyNavCtrlrSubClass alloc]initWithNibName:#"MenuController" bundle:nil];
[tabBarController presentModalViewController:menu animated:anim];
MenuController itself is structured as follows:
MenuController.xib
File's Owner (MyNavCtrlrSubClass : UIViewController)
Navigation Controller (UINavigationController)
Navigation Bar (UINavigationBar)
Root View Controller (Nib Name is set to load AnotherViewController.nib)
Navigation Item -> (UINavigationItem)
This all works fine, except that when MyNavCtrlrSubClass is loaded, I get the following error:
Loaded the "MenuController" nib but the view outlet was not set
It's clear why this is happening - File's Owner doesn't have an outlet connection for its view. The question is what should I set as its view, and does something have to be set in the first place? The Navigation Bar is the only candidate in MenuController.xib, but doing this will just size the UINavigationBar itself to the fullscreen mode, so to speak.
I'm obviously missing something in IB, but what? MyNavCtrlrSubClass.m has no code itself, except an IBOutlet for the UINavigationController. Am I making a mistake trying to set this up entirely in IB? The idea is to keep the modal Navigation Controller in one nib, and all the views it loads in separate nibs, but since MenuController is just a container for the navigation and contains no views itself, I'm obviously designing it wrong. :)
If you're wondering why I'm not designing it some other way, it's because I'm trying to obey my (possibly mistaken) perception of how IB asks you to build an ideal hierarchy.
Any help would be greatly appreciated.
I think you might not be understanding how the File's Owner is meant to be used in a NIB file. I've written up a response describing the file's owner under another question.
When you invoke this line:
[[MyNavCtrlrSubClass alloc] initWithNibName:#"MenuController" bundle:nil]
You create an instance of MyNavCtrlrSubClass, and tell it to load #"MenuController". Then in the MenuController.xib file, there is a second unrelated UINavigationController with things inside of it. When MenuController.nib is loaded at runtime, that second navigation controller will be created.
A second problem is that telling a UINavigationController to load a NIB file isn't really sensible because navigation controllers create and manage their own views. You really want to create the root view controller, and tell that view controller to load a NIB file.
Try this:
MyRootViewController *rootController = [[[MyRootViewController alloc] initWithNibName:#"AnotherViewController" bundle:nil] autorelease];
MyNavCtrlrSubClass *menu = [[MyNavCtrlrSubClass alloc] initWithRootViewController:rootController];
Where your XIB File looks like this:
File's Owner (Class set to MyRootViewController, view outlet connected to subsequent UIView)
UIView
Subview A
Subview B
After you're confortable with how all of this is working, you might also consider instantiating the navigation controller and root view controller in one XIB file like you were starting to do in the code you posted.
The crux of this question is stated by Travis himself: "How would you load Navigation Controller nib, designing as much as possible in Interface Builder?" And also from the example, it looks like this means the UINavigationController and associated UIViewControllers.
With this interpretation, the answer is you cannot fully configure a UINavigationController and it's UIViewControllers in a single XIB. Yes it is intuitive to want to do this so you are not crazy.
When I say you cannot do this, I mean the most commonly used framework methods do not have a way to handle this. There is no [UINavigationController alloc] initWithMegaNibName. Yes you could stuff almost anything in a single XIB and write code to hydrate objects in special ways, but I don't think that's what you're looking for.
You could use two or more XIBs as Jon suggested, but then things are less self contained and so you have many folks who find it simpler to do part, or all, of the controllers in code.
Unfortunately there is not a 1:1 correspondance between Interface Builder capability and code like there is on other dev platforms. I generally prefer to be able let designers participate as much as possible in creating assets, but most of them I know do not code objective-c.
In IB, in the MenuController nib add a UIView and set that view as the outlet. You will need to set that view for a UIViewController. Here is a quick link to an Apple page showing a basic setup. Not sure if it will help you at your current stage though.