In my program, I have a UIViewController subclass MyViewController and two subclasses of that view controller.
I want them all to use the same xib so I initiate them as
SubClass *SC = [[SubClass alloc] initWithNibName:#"MyViewController" bundle:nil];
[self presentModalViewController:SC animated:NO];
[SC release];
SubClass is a subclass of MyViewController, which is a subclass of UIViewController. In MyViewController.xib, I have File's Owner set to MyViewController.
If I only was going to have two subclasses, I would probably just duplicate the xib but I plan to have many, many subclasses, all using the same xib.
You can load any XIB with
- (NSArray *)loadNibNamed:(NSString *)name owner:(id)owner options:(NSDictionary *)options
of the NSBundle class. With
NSArray *arr = [[NSBundle mainBundle] loadNibNamed:#"foo" owner:nil options:nil];
you can load all contents of a XIB into an array. The order of the items in the array is the same you defined in Interface Builder without File's Owner and First Responder.
Related
I am stumbling over what I believe is probably a fundamental misunderstanding of how classes work in Objective-C. I am using Storyboards but in this app I wanted to create a simple custom date picker view for a textfield on one of my view controllers. However, I seem to be having a problem accessing any of the properties of the date picker class from my view controller:
First I modeled my CustomDatePicker.xib in IB as follows:
I have created a custom class by sublcassing UIView as follows:
CustomPicker.h
#interface CustomPickerView : UIView
#property (strong, nonatomic) IBOutlet UIDatePicker* datePicker;
#end
CustomerPicker.m
#implementation CustomPickerView
- (id)init
{
self = [super initWithFrame:CGRectMake(0, 0, 320, 258)];
if (self) {
[self addSubview:[[[NSBundle mainBundle] loadNibNamed:#"CustomPickerView" owner:self options:nil] objectAtIndex:0]];
}
return self;
}
In my ViewController:
- (void)viewDidLoad
{
[super viewDidLoad];
self.customPickerView=[[CustomPickerView alloc] init];
// THE MAIN ISSUE IS...
// Following line has no effect on how picker is presented ???
self.customPickerView.datePicker.datePickerMode=UIDatePickerModeTime;
self.dateField.inputView=self.customPickerView;
}
When the textfield is tapped, my CustomDatePicker pops up fine. However, I can't seem to set the .datePickerMode either from the viewDidLoad method of my ViewController. The only way I can change the .datePickerMode is through IB and of course that's not going to work at run-time.
I have wired up the outlet in IB and am able to access the datePicker.date from within the class but not the ViewController.
I have researched and viewed a number of ways to implement this concept. My question isn't how to implement a CustomDatePicker it is "Why can't I access properties of my CustomDatePicker from the ViewController that instantiated it?
I successfully changed the datePickerMode property when I loaded the NIB like this:
- (void)viewDidLoad
{
[super viewDidLoad];
NSArray *nibArray = [[NSBundle mainBundle] loadNibNamed:#"CustomPickerView" owner:self options:nil];
self.customPickerView = (CustomPickerView *)[nibArray objectAtIndex:0];
self.customPickerView.datePicker.datePickerMode = UIDatePickerModeTime;
self.dateField.inputView = self.customPickerView;
}
And you can probably remove your custom view's init method altogether. I've never seen a NIB loaded in the init method like you're doing. While it might be possible, I believe that's what is causing your problem. Loading the NIB in viewDidLoad of the ViewController and setting it directly seems more straightforward.
Please see solution here at:
Objective-C Custom Class Actions and Outlets
My goal is, to have a subclassed UIView (lets call it infoView) designed in his own XIB so that I can present it in many UIViewController's.
The Problem:
So far, when I was adding UIView's to a UIViewController I always had to make an UIViewController the file's owner of the UIView's .xib file to load the view with something like:
...
//this is inside the calling UIViewController's method
// InfoView *infoView is ivar and a subclass of UIView
infoView = nil;
NSArray *bundle = [[NSBundle mainBundle] loadNibNamed:#"InfoView"
owner:self options:nil];
for (id object in bundle) {
if ([object isKindOfClass:[InfoView class]])
infoView = (InfoView *)object;
}
[[self view] addSubview:infoView];
...
But I want to use the same UIView in many different UIViewController's, so I actually don't want a file's owner except maybe the class itself. In ThomasM's question he was setting the UIView itself to be the file's owner but without success.
In the answers there I found a solution to set the file's owner to nil. To do so I had to add all calling UIViewController objects from the Interface Builder object library to the InfoView.xib file and connect them with their infoView outlets.
But this doesn't feel right. So here I would like to collect solutions to
encapsulate a UIView together with his xib-file to use it in many different view controllers. How do you guys handle that?
Thx for any help.
EDIT:
The infoView is something like an overlay which appears when the user presses a button on one of the view controllers. It's NOT the View controllers "main" view. It gives detailed informations about the view of his superviews view controller and will disappear afterwards. I only fill the infoView with different contents threw out all the calling view controllers.
Like Hollance answer was pointing out I am using UINib.
To use it, leave the .xib files owner nil and place all customization of the infoView inside the initWithCoder: method of your InfoView class implementation. This will get called if you obtain the InfoView.xib like:
// here InfoView is the name of the .xib file
UINib *infoNib = [UINib nibWithNibName:#"InfoView" bundle:nil];
NSArray *topLevelObjects = [infoNib instantiateWithOwner:self options:nil];
QInfoView *infoView = [topLevelObjects objectAtIndex:0];
So you want to load a UIView from a nib that you wish to use in more than one UIViewController, and you want to connect it to an outlet on each of those view controllers. Is that correct?
Then make a UIViewController subclass (let's call it FakeViewController) with an IBOutlet property. Set that FakeViewController as the nib's File's Owner and connect your UIView to its outlet.
Done.
You just need to make sure all your other view controllers also have these outlet properties (although they don't need to be IBOutlets), but the nib loader doesn't actually check to make sure the class that you pass into the owner parameter equals the class name you specified in Interface Builder. So you can fake it.
Oh, and if you're OS 4.0 and higher, use UINib to load the nib file.
And yet another way is to create your own "controller" based on NSObject to define your own life-circle (instead of standard UIViewController life-circle).
For example:
BaseSubview.h:
#interface BaseSubview : NSObject {
UIView* _view;
}
#property (nonatomic, retain) IBOutlet UIView* view;
- (void)myMethod;
#end
BaseSubview.m:
#import "BaseSubview.h"
#implementation BaseSubview
#synthesize view = _view;
- (id)init
{
self = [super init];
if (self) {
// ...
}
return self;
}
- (void)dealloc
{
[_view removeFromSuperView];
[super dealloc];
}
- (void)myMethod
{
// view specific logic here
_view.backgroundColor = [UIColor redColor];
}
#end
InfoView.h:
#import "BaseSubview"
#interface InfoView : BaseSubview {
UILabel* _labelInfo;
}
#property (nonatomic, retain) IBOutlet UILabel* labelInfo;
#end
InfoView.m:
#import "InfoView.h"
#implementation InfoView
#synthesize labelInfo = _labelInfo;
- (id)init
{
self = [super init];
if (self) {
// ...
}
return self;
}
- (void)myMethod
{
// view specific logic here
_labelInfo.text = #"current time...";
[super myMethod];
}
#end
InfoView.xib:
file owner is InfoView
assign of outlets as usual
view is parent all other controls (such as labels, etc)
HugeAndComplicatedViewController.h:
// ...
// among other var definitions
InfoView* _infoView;
// ...
HugeAndComplicatedViewController.m, most interesting part:
// when you decide to show your view
// probably in loadView
_infoView = [[InfoView alloc] init];
[[NSBundle mainBundle] loadNibNamed:#"InfoView" owner:_infoView options:nil];
[self.view addSubview:_infoView.view];
// possibly perform specific logic
[_infoView myMethod];
// no need sub-view any more
// probably in dealloc
[_infoView release];
So now you have your own sub-view with logic and design separated from "Huge & Complicated" view-controller. It can have any life-circle you need for your current project.
does infoView need to be a subview?
in your viewController:
-(id) init {
self = [super initWithNibName:#"myNib" bundle:nil];
if (self) {
// code here
}
}
The idea basically is:
Inside of myViewController NIB I have a UIView as a subview, with connections to an IBOutlet on MyViewController class. I want to load the UIView subview from a NIB also. The subView also has a class associated with it. But the subview is not showing. Here is what I do
on MyViewController.h
#interface MyViewController : UIViewController {
IBOutlet SubView *subView; // this outlet is connected to an empty UIView on IB
}
#end
on MyViewController.m
-(id)init {
if ((self = [super init])) {
// load the main view
[[NSBundle mainBundle] loadNibNamed:#"myViewController" owner:self options:nil];
// load the sub view from another NIB
self.subView = [[[NSBundle mainBundle] loadNibNamed:#"subView" owner:self options:nil] objectAtIndex:0];
}
}
the SubView.h is defined as:
#interface SubView : UIView {
}
#end
What am I doing wrong?
What you need to do is set your file owner to be a UIViewController, hook up your view to the view property of the file owner, save your nib. In your code, load your nib like this:
UIViewController* c = [[UIViewController alloc] initWithNibName:#"Foo" bundle:nil];
SubView* subView = [c view];
Should be off to the races.
One final note, is that the type of subView should be the same as whatever is defined as the class name in interface builder. If it's a SubView there, then it's safe to declare it as a SubView* in code.
GianPac - shameless self-promotion, but I did a blog post about this about a month ago. Feel free to ignore the drop-shadow related code.
http://nathanhjones.com/2011/02/20/creating-reusable-uiviews-with-a-drop-shadow-tutorial/
Also, I (thanks to advice from several people) avoid ever having more than one view controller on my 'view'. The method I outline above allows you to accomplish this and still use IB to do the layout/outlets.
This question already has answers here:
UIView and initWithFrame and a NIB file. How can I get the NIB file loaded?
(5 answers)
Closed 7 years ago.
I created a custom UIView subclass, and would prefer to not layout the UI in code in the UIView subclass. I'd like to use a xib for that. So what I did is the following.
I created a class "ShareView" which subclasses UIView. I created a XIB file with its file's owner set to "ShareView". Then I link some outlets I declared in my "ShareView.h".
Next I have a ViewController, MainViewController, which adds the ShareView as a subview. whith this code:
NSArray *arr = [[NSBundle mainBundle] loadNibNamed:#"ShareView" owner:nil options:nil];
UIView *fv = [[arr objectAtIndex:0] retain];
fv.frame = CGRectMake(0, 0, 320, 407);
[self.view addSubview:fv];
But now I get NSUnknownKeyException errors on the outlets I declared in my ShareView.
The reason I did all this is because I want a UIView, with its own logic in a seperate XIB file. I read in several places that ViewControllers are only used to manage a full screen, i.e. not parts of a screen...
So what am I doing wrong? I want my logic for ShareView in a seperate class, so my MainController class doesn't get bloated with logic from ShareView (which I think is an aption to solve this problem?)
ThomasM,
We had similar ideas about encapsulating behavior inside a custom view (say, a slider with companion labels for min/max/current values, with value-changed events also handled by the control internally).
In our current best-practice, we would design the ShareView in Interface Builder (ShareView.xib), as described by Eimantas in his answer. We then embed the ShareView to the view hierarchy in MainViewController.xib.
I wrote up how we embed custom-view Nibs inside other Nibs in our iOS developer blog. The crux is overriding -awakeAfterUsingCoder: in your custom view, replacing the object loaded from MainViewController.xib with the one loaded from the "embedded" Nib (ShareView.xib).
Something along these lines:
// ShareView.m
- (id) awakeAfterUsingCoder:(NSCoder*)aDecoder {
BOOL theThingThatGotLoadedWasJustAPlaceholder = ([[self subviews] count] == 0);
if (theThingThatGotLoadedWasJustAPlaceholder) {
// load the embedded view from its Nib
ShareView* theRealThing = [[[NSBundle mainBundle] loadNibNamed:NSStringFromClass([ShareView class]) owner:nil options:nil] objectAtIndex:0];
// pass properties through
theRealThing.frame = self.frame;
theRealThing.autoresizingMask = self.autoresizingMask;
[self release];
self = [theRealThing retain];
}
return self;
}
You defined owner of the loaded xib as nil. Since file owner in xib itself has outlets connected and is defined as instance of ShareView you get the exception about unknown keys (nil doesn't have outleted properties you defined for ShareView).
You should define the loader of the xib as owner (i.e. view controller responsible for loading the xib). Then add separate UIView object to xib and define it as instance of ShareView. Then when loading the xib.
ShareView *shareView = [[[[NSBundle mainBundle] loadNibNamed:#"ShareView" owner:self options:nil] objectAtIndex:0] retain];
You can also define shareView as an IBOutlet in view controller's interface (and connect the outlet from file owner to that view in the xib itself). Then when you load the xib there won't be any need for reassigning the shareView instance variable since the xib loading process will reconnect the view to the instance variable directly.
I would like to add to the answer. I hope people would improve this answer though.
First of all it DOES work.
XIB:
Result:
I would like to subclass UIView for a long time especially for tableViewCell.
This is how I did it.
It's succesful, but some part is still "awkward" in my opinion.
First I created a usual .h, .m, and xib file. Notice that Apple do not have the check box to automatically create an xib if the subclass you created is not a subclass of UIViewController. Well create those anyway.
#import <UIKit/UIKit.h>
#import "Business.h"
#interface BGUIBusinessCellForDisplay : UITableViewCell
+ (NSString *) reuseIdentifier;
- (BGUIBusinessCellForDisplay *) initWithBiz: (Business *) biz;
#end
Really simple UITableViewCell, that I want to initialize latter with biz.
I put reuseidentifier which you should do for UITableViewCell
//#import "Business.h"
#interface BGUIBusinessCellForDisplay ()
#property (weak, nonatomic) IBOutlet UILabel *Title;
#property (weak, nonatomic) IBOutlet UIImageView *Image;
#property (weak, nonatomic) IBOutlet UILabel *Address;
#property (weak, nonatomic) IBOutlet UILabel *DistanceLabel;
#property (weak, nonatomic) IBOutlet UILabel *PinNumber;
#property (strong, nonatomic) IBOutlet BGUIBusinessCellForDisplay *view;
#property (weak, nonatomic) IBOutlet UIImageView *ArrowDirection;
#property (weak, nonatomic) Business * biz;
#end
#implementation BGUIBusinessCellForDisplay
- (NSString *) reuseIdentifier {
return [[self class] reuseIdentifier];
};
+ (NSString *) reuseIdentifier {
return NSStringFromClass([self class]);
};
Then I eliminated most init codes and put this instead:
- (BGUIBusinessCellForDisplay *) initWithBiz: (Business *) biz
{
if (self.biz == nil) //First time set up
{
self = [super init]; //If use dequeueReusableCellWithIdentifier then I shouldn't change the address self points to right
NSString * className = NSStringFromClass([self class]);
//PO (className);
[[NSBundle mainBundle] loadNibNamed:className owner:self options:nil];
[self addSubview:self.view]; //What is this for? self.view is of type BGCRBusinessForDisplay2. That view should be self, not one of it's subview Things don't work without it though
}
if (biz==nil)
{
return self;
}
self.biz = biz;
self.Title.text = biz.Title; //Let's set this one thing first
self.Address.text=biz.ShortenedAddress;
//if([self.distance isNotEmpty]){
self.DistanceLabel.text=[NSString stringWithFormat:#"%dm",[biz.Distance intValue]];
self.PinNumber.text =biz.StringPinLineAndNumber;
Notice that it's really awkward.
First of all the init can be used in 2 ways.
It can be used to right after aloc
It can be used by we having another existing class and then we just want to init that existing cell to another biz.
So I did:
if (self.biz == nil) //First time set up
{
self = [super init]; //If use dequeueReusableCellWithIdentifier then I shouldn't change the address self points to right
NSString * className = NSStringFromClass([self class]);
//PO (className);
[[NSBundle mainBundle] loadNibNamed:className owner:self options:nil];
[self addSubview:self.view]; //What is this for? self.view is of type BGCRBusinessForDisplay2. That view should be self, not one of it's subview Things don't work without it though
}
Another icky things that I did is when I do [self addSubview:self.view];
The thing is I want self to be the view. Not self.view. Somehow it works nevertheless. So yea, please help me improve, but that's essentially the way to implement your own subclass of UIView.
You can create your custom UIView designed in xib and even make Interface Builder to display it inside other xib files or storyboards in new Xcode 6 using IB_DESIGNABLE. In xib set file owner to your custom class but do not set UIView class to avoid recurrency loading problems. Just leave default UIView class and you will add this UIView as a subview of your custom class view. Connect all your outlets to file owner and in your custom class load your xib like in the code below. You can check my video tutorial here: https://www.youtube.com/watch?v=L97MdpaF3Xg
IB_DESIGNABLE
#interface CustomControl : UIView
#end
#implementation CustomControl
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super initWithCoder:aDecoder])
{
[self load];
}
return self;
}
- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame])
{
[self load];
}
return self;
}
- (void)load
{
UIView *view = [[[NSBundle bundleForClass:[self class]] loadNibNamed:#"CustomControl" owner:self options:nil] firstObject];
[self addSubview:view];
view.frame = self.bounds;
}
#end
If you are using autolayout then you might want to change: view.frame = self.bounds; to:
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[view]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[view]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)]];
To use Yang's pattern with Auto-Layout, you need to add the following somewhere in the -awakeWithCoder: method.
theRealThing.translatesAutoresizingMaskIntoConstraints = NO;
If you don't turn off -translatesAutoResizingMaskIntoConstraints it can cause your layout to be incorrect as well as causing a LOT of debugging nonsense in the console.
EDIT: Auto-layout can still be a pain. Certain constraints aren't respected, but other are (e.g. pinning to the bottom doesn't work but pinning to the top does). We're not exactly sure why, but you can work around this by manually passing constraints from the placeholder to theRealThing.
It's also worth noting that this pattern works just the same way with Storyboards as it does with regular .xibs (i.e. you can create a UI Element in a .xib and drop it into a StoryBoard View controller by following your steps.)
Instead of subclassing UIView why don't you subclass UIViewController. Check out the following link. In that made a "RedView" and "BlueView" UIViewControllers with their xibs and added them to the MultipleViewsController view by creating and instance of the former two classes and adding [self.view addSubview:red.view] and [self.view addSubview:blue.view] in the MultipleViewsController's viewDidLoad method
MultipleControllers in one view
Just add (id)sender to the button pressed function in RedView and BlueView in the code of the above link.
After a litte hunting through the docs I have decided on the following technique using "viewWithTag" to extract sub views from the main root view returned by loadNibNamed:owner:options: To start with I was a little confused as I assumed loadNibNamed:owner:options would return an array containing all my UI items (i.e. labels, buttons etc.) when in fact it seems to return the root view (or root views). Can anyone confirm that I am doing this right, I am just curious if there are other (maybe better) ways to extract and set items from within a xib file?
- (void)loadView {
NSLog(#"HYBRID UI: %s", __PRETTY_FUNCTION__);
NSArray *nibArchive = [[NSBundle mainBundle] loadNibNamed:#"Interface" owner:self options:nil];
NSLog(#"SIZE: %d ARRAY: %#", [nibArchive count], nibArchive);
// UIView
UIView *nibView = [nibArchive lastObject];
[nibView setFrame:[[UIScreen mainScreen] applicationFrame]];
NSLog(#"FRAME: %#", NSStringFromCGRect([nibView frame]));
[self setView: nibView];
// UILabel
UILabel *nibLabel = (UILabel *)[nibView viewWithTag:101];
[nibLabel setText:#"FRINGE"];
[nibLabel setTextColor:[UIColor whiteColor]];
// UIImageView
UIImageView *nibImageView = (UIImageView *)[nibView viewWithTag:102];
[nibImageView setBackgroundColor:[UIColor whiteColor]];
}
cheers gary
loadNibNamed:owner:options: does return an array of all root objects in the NIB. To get to other objects in the hierarchy, you can traverse the hierarchy manually (not a good idea in most cases), use tags as you did or use outlets.
If you declare outlets in your view controller for the view, the label and the image view and connect them in the NIB to the appropriate objects, they will be automatically connected in loadNibNamed:owner:options:.
PS: Why do you load the NIB manually anyway? Can't you init your view controller with initWithNibName:bundle and do the rest of the initialization in viewDidLoad?
It seems like you're making this harder than it needs to be. If you're subclassing UIViewController, just call [super initWithNibName:#"whatever" bundle:nil] in your init, then you won't have to call loadNibNamed:owner:options yourself. And since you're using a nib, you should put your code in viewDidLoad without implementing loadView.
In your interface, set up an IBOutlet for the views you are interested in:
#property (nonatomic, retain) IBOutlet UILabel *titleLabel;
In the nib, set the File's Owner class to your UIViewController subclass, and then you can connect the titleLabel to the actual UILabel.