Correct way to load a Nib for a UIView subclass
I am aware this question has been asked before but the answers are contradicting and I am confused, so please don't flame me.
I want to have a reusable UIView
subclass throughout my app. I want to describe the interface using a nib file.
Now let's say it's a loading indicator view with an activity indicator in it. I would like on some event to instantiate this view and animate in to a view controller's view. I could describe the view's interface no problem programmatically, creating the elements programmatically and setting their frame inside an init method etc.
How can I do this using a nib though? Maintaining the size given in interface builder without having to set a frame.
I've managed to do it like this, but I'm sure it is wrong (it's just a view with a picker in it):
- (id)initWithDataSource:(NSDictionary *)dataSource {
self = [super init];
if (self){
self = [[[NSBundle mainBundle] loadNibNamed:[NSString stringWithFormat:@"%@", [self class]] owner:self options:nil] objectAtIndex:0];
self.pickerViewData = dataSource;
[self configurePickerView];
}
return self;
}
But I'm overwriting self, and when I instantiate it:
FSASelectView *selectView = [[FSASelectView alloc] initWithDataSource:selectViewDictionary];
selectView.delegate = self;
selectView.frame = CGRectMake(0, self.view.bottom + 50, [FSASelectView width], [FSASelectView height]);
I have to manually set the frame rather than have it picked up from IB.
EDIT: I want to create this custom view in a view controller, and have access to control the view's elements. I don't want a new view controller.
Thanks
EDIT: I Don't know if this is best practice, I'm sure it's not, but this is how I did it:
FSASelectView *selectView = [[[NSBundle mainBundle] loadNibNamed:[NSString stringWithFormat:@"%@",[FSASelectView class]] owner:self options:nil] objectAtIndex:0];
selectView.delegate = self;
[selectView configurePickerViewWithData:ds];
selectView.frame = CGRectMake(0, self.view.bottom + 50, selectView.width, selectView.height);
selectView.alpha = 0.9;
[self.view addSubview:selectView];
[UIView animateWithDuration: 0.25 delay: 0 options:UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionCurveEaseInOut animations:^{
selectView.frame = CGRectMake(0, self.view.bottom - selectView.height, selectView.width, selectView.height);
selectView.alpha = 1;
} completion:^(BOOL finished) {
}];
Correct practice still wanted
Should this have been done using a view controller and init with nib name? Should I have set the nib in some UIView initialisation method in the code? Or is what I have done ok?
MyViewClass *myViewObject = [[[NSBundle mainBundle] loadNibNamed:@"MyViewClassNib" owner:self options:nil] objectAtIndex:0]
I'm using this to initialise the reusable custom views I have.
Note that you can use "firstObject" at the end there, it's a little cleaner. "firstObject" is a handy method for NSArray and NSMutableArray.
Here's a typical example, of loading a xib to use as a table header. In your file YourClass.m
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
return [[NSBundle mainBundle] loadNibNamed:@"TopArea" owner:self options:nil].firstObject;
}
Normally, in the TopArea.xib
, you would click on File Owner and set the file owner to YourClass. Then actually in YourClass.h you would have IBOutlet properties. In TopArea.xib
, you can drag controls to those outlets.
Don't forget that in TopArea.xib
, you may have to click on the View itself and drag that to some outlet, so you have control of it, if necessary. (A very worthwhile tip is that when you are doing this for table cell rows, you absolutely have to do that - you have to connect the view itself to the relevant property in your code.)
If you want to keep your CustomView
and its xib
independent of File's Owner
, then follow these steps
- Leave the
File's Owner
field empty. - Click on actual view in
xib
file of yourCustomView
and set itsCustom Class
asCustomView
(name of your custom view class) - Add
IBOutlet
in.h
file of your custom view. - In
.xib
file of your custom view, click on view and go inConnection Inspector
. Here you will all your IBOutlets which you define in.h
file - Connect them with their respective view.
in .m
file of your CustomView
class, override the init
method as follow
-(CustomView *) init{
CustomView *result = nil;
NSArray* elements = [[NSBundle mainBundle] loadNibNamed: NSStringFromClass([self class]) owner:self options: nil];
for (id anObject in elements)
{
if ([anObject isKindOfClass:[self class]])
{
result = anObject;
break;
}
}
return result;
}
Now when you want to load your CustomView
, use the following line of code
[[CustomView alloc] init];
Follow the following steps
- Create a class named MyView .h/.m of type
UIView
. - Create a xib of same name
MyView.xib
. - Now change the File Owner class to
UIViewController
fromNSObject
in xib. See the image below Connect the File Owner View to your View. See the image below
Change the class of your View to
MyView
. Same as 3.- Place controls create IBOutlets.
Here is the code to load the View:
UIViewController *controller=[[UIViewController alloc] initWithNibName:@"MyView" bundle:nil];
MyView* view=(MyView*)controller.view;
[self.view addSubview:myview];
Hope it helps.
Clarification:
UIViewController
is used to load your xib and the View which the UIViewController
has is actually MyView
which you have assigned in the MyView xib..
Demo I have made a demo grab here
Answering my own question about 2 or something years later here but...
It uses a protocol extension so you can do it without any extra code for all classes.
/*
Prerequisites
-------------
- In IB set the view's class to the type hook up any IBOutlets
- In IB ensure the file's owner is blank
*/
public protocol CreatedFromNib {
static func createFromNib() -> Self?
static func nibName() -> String?
}
extension UIView: CreatedFromNib { }
public extension CreatedFromNib where Self: UIView {
public static func createFromNib() -> Self? {
guard let nibName = nibName() else { return nil }
guard let view = NSBundle.mainBundle().loadNibNamed(nibName, owner: nil, options: nil).last as? Self else { return nil }
return view
}
public static func nibName() -> String? {
guard let n = NSStringFromClass(Self.self).componentsSeparatedByString(".").last else { return nil }
return n
}
}
// Usage:
let myView = MyView().createFromNib()
In Swift:
For example, name of your custom class is InfoView
At first, you create files InfoView.xib
and InfoView.swift
like this:
import Foundation
import UIKit
class InfoView: UIView {
class func instanceFromNib() -> UIView {
return UINib(nibName: "InfoView", bundle: nil).instantiateWithOwner(nil, options: nil)[0] as! UIView
}
Then set File's Owner
to UIViewController
like this:
Rename your View
to InfoView
:
Right-click to File's Owner
and connect your view
field with your InfoView
:
Make sure that class name is InfoView
:
And after this you can add the action to button in your custom class without any problem:
And usage of this custom class in your MainViewController
:
func someMethod() {
var v = InfoView.instanceFromNib()
v.frame = self.view.bounds
self.view.addSubview(v)
}