Here is my Objective-C code which I'm using to load a nib for my customised UIView:
-(id)init{
NSArray *subviewArray = [[NSBundle mainBundle] loadNibNamed:@"myXib" owner:self options:nil];
return [subviewArray objectAtIndex:0];
}
What is the equivalent code in Swift?
Now being able to return -> Self in swift helps simplify this a bit. Last confirmed on Swift 5.
extension UIView {
class func fromNib(named: String? = nil) -> Self {
let name = named ?? "\(Self.self)"
guard
let nib = Bundle.main.loadNibNamed(name, owner: nil, options: nil)
else { fatalError("missing expected nib named: \(name)") }
guard
/// we're using `first` here because compact map chokes compiler on
/// optimized release, so you can't use two views in one nib if you wanted to
/// and are now looking at this
let view = nib.first as? Self
else { fatalError("view of type \(Self.self) not found in \(nib)") }
return view
}
}
If your .xib file and subclass share the same name, you can use:
let view = CustomView.fromNib()
If you have a custom name, use:
let view = CustomView.fromNib(named: "special-case")
NOTE:
If you're getting the error "view of type YourType not found in.." then you haven't set the view's class in the .xib file
Select your view in the .xib file, and press cmd + opt + 4 and in the class input, enter your class
let subviewArray = NSBundle.mainBundle().loadNibNamed("myXib", owner: self, options: nil)
return subviewArray[0]
I prefer the below extension
extension UIView {
class var instanceFromNib: Self {
return Bundle(for: Self.self)
.loadNibNamed(String(describing: Self.self), owner: nil, options: nil)?.first as! Self
}
}
The difference between this and the top answered extension is you don't need to store it an constant or variable.
class TitleView: UIView { }
extension UIView {
class var instanceFromNib: Self {
return Bundle(for: Self.self)
.loadNibNamed(String(describing: Self.self), owner: nil, options: nil)?.first as! Self
}
}
self.navigationItem.titleView = TitleView.instanceFromNib
I just do this way :
if let myView = UINib.init(nibName: "MyView", bundle: nil).instantiate(withOwner: self)[0] as? MyView {
// Do something with myView
}
This sample uses the first view in the nib "MyView.xib" in the main bundle. But you can vary either the index, the nib name, or the bundle ( main by default ).
I used to awake views into the view init method or make generic methods as in the proposed answers above ( which are smart by the way ), but I don't do it anymore because I have noticed use cases are often different, and to cover all cases, generic methods become as complex as using the UINib.instantiate method.
I prefer to use a factory object, usually the ViewController that will use the view, or a dedicated factory object or view extension if the view needs to be used in multiple places.
In this example, a ViewController loads a view from nib. The nib file can be changed to use different layouts for the same view class. ( This not nice code, it just illustrates the idea )
class MyViewController {
// Use "MyView-Compact" for compact version
var myViewNibFileName = "MyView-Standard"
lazy var myView: MyView = {
// Be sure the Nib is correct, or it will crash
// We don't want to continue with a wrong view anyway, so ! is ok
UINib.init(nibName: myViewNibFileName, bundle: nil).instantiate(withOwner: self)[0] as! MyView
}()
}
//
// Refactored by Essam Mohamed Fahmi.
//
import UIKit
extension UIView
{
static var nib: UINib
{
return UINib(nibName: "\(self)", bundle: nil)
}
static func instantiateFromNib() -> Self?
{
return nib.instantiate() as? Self
}
}
extension UINib
{
func instantiate() -> Any?
{
return instantiate(withOwner: nil, options: nil).first
}
}
let myCustomView: CustomView = .instantiateFromNib()
You can do this via storyboard, just add proper constraints for view. You can do this easily by subclassing any view from your own let's say BaseView:
Objective-C
BaseView.h
/*!
@class BaseView
@discussion Base View for getting view from xibFile
@availability ios7 and later
*/
@interface BaseView : UIView
@end
BaseView.m
#import "BaseView.h"
@implementation BaseView
#pragma mark - Public
- (instancetype)initWithCoder:(NSCoder *)coder
{
self = [super initWithCoder:coder];
if (self) {
[self prepareView];
}
return self;
}
#pragma mark - LifeCycle
- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self prepareView];
}
return self;
}
#pragma mark - Private
- (void)prepareView
{
NSArray *nibsArray = [[NSBundle mainBundle] loadNibNamed:NSStringFromClass([self class]) owner:self options:nil];
UIView *view = [nibsArray firstObject];
view.translatesAutoresizingMaskIntoConstraints = NO;
[self addSubview:view];
[self addConstraintsForView:view];
}
#pragma mark - Add constraints
- (void)addConstraintsForView:(UIView *)view
{
[self addConstraints:@[[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:self attribute:NSLayoutAttributeBottom
multiplier:1.0
constant:0],
[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self attribute:NSLayoutAttributeTop
multiplier:1.0
constant:0],
[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:self attribute:NSLayoutAttributeLeft
multiplier:1.0
constant:0],
[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeRight
relatedBy:NSLayoutRelationEqual
toItem:self attribute:NSLayoutAttributeRight
multiplier:1.0
constant:0]
]];
}
@end
Swift 4
import UIKit
class BaseView : UIView {
// MARK: - LifeCycle
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
prepareView()
}
override init(frame: CGRect) {
super.init(frame: frame)
prepareView()
}
internal class func xibName() -> String {
return String(describing: self)
}
// MARK: - Private
fileprivate func prepareView() {
let nameForXib = BaseView.xibName()
let nibs = Bundle.main.loadNibNamed(nameForXib, owner: self, options: nil)
if let view = nibs?.first as? UIView {
view.backgroundColor = UIColor.clear
view.translatesAutoresizingMaskIntoConstraints = false
addSubviewWithConstraints(view, offset: false)
}
}
}
UIView+Subview
public extension UIView {
// MARK: - UIView+Extensions
public func addSubviewWithConstraints(_ subview:UIView, offset:Bool = true) {
subview.translatesAutoresizingMaskIntoConstraints = false
let views = [
"subview" : subview
]
addSubview(subview)
var constraints = NSLayoutConstraint.constraints(withVisualFormat: offset ? "H:|-[subview]-|" : "H:|[subview]|", options: [.alignAllLeading, .alignAllTrailing], metrics: nil, views: views)
constraints.append(contentsOf: NSLayoutConstraint.constraints(withVisualFormat: offset ? "V:|-[subview]-|" : "V:|[subview]|", options: [.alignAllTop, .alignAllBottom], metrics: nil, views: views))
NSLayoutConstraint.activate(constraints)
}
}
I provide 2 variants how to add constraints - common one and within visual format language - select any you want :)
Also, by default assumed that xib name has same name as implementation class name. If no - just change xibName parameter.
If you subclass your view from BaseView - you can easily put any view and specify class in IB.
Similar to some of the answers above but a more consistent Swift3 UIView extension:
extension UIView {
class func fromNib<A: UIView> (nibName name: String, bundle: Bundle? = nil) -> A? {
let bundle = bundle ?? Bundle.main
let nibViews = bundle.loadNibNamed(name, owner: self, options: nil)
return nibViews?.first as? A
}
class func fromNib<T: UIView>() -> T? {
return fromNib(nibName: String(describing: T.self), bundle: nil)
}
}
Which gives the convenience of being able to load the class from a self named nib but also from other nibs/bundles.
Here is a clean and declarative way of programmatically loading a view using a protocol and protocol extension (Swift 4.2):
protocol XibLoadable {
associatedtype CustomViewType
static func loadFromXib() -> CustomViewType
}
extension XibLoadable where Self: UIView {
static func loadFromXib() -> Self {
let nib = UINib(nibName: "\(self)", bundle: Bundle(for: self))
guard let customView = nib.instantiate(withOwner: self, options: nil).first as? Self else {
// your app should crash if the xib doesn't exist
preconditionFailure("Couldn't load xib for view: \(self)")
}
return customView
}
}
And you can use this like so:
// don't forget you need a xib file too
final class MyView: UIView, XibLoadable { ... }
// and when you want to use it
let viewInstance = MyView.loadFromXib()
Some additional considerations:
Custom Class set (and outlets/actions set from there), not the File Owner's.Swift 4
Don't forget to write ".first as? CustomView".
if let customView = Bundle.main.loadNibNamed("myXib", owner: self, options: nil)?.first as? CustomView {
self.view.addSubview(customView)
}
If you want to use anywhere
The Best Solution is Robert Gummesson's answer.
extension UIView {
class func fromNib<T: UIView>() -> T {
return Bundle.main.loadNibNamed(String(describing: T.self), owner: nil, options: nil)![0] as! T
}
}
Then call it like this:
let myCustomView: CustomView = UIView.fromNib()
If you want the Swift UIView subclass to be entirely self contained, and have the ability to be instantiated using init or init(frame:) without exposing the implementation detail of using a Nib, then you can use a protocol extension to achieve this. This solution avoids the nested UIView hierarchy as suggested by many of the other solutions.
public class CustomView: UIView {
@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var valueLabel: UILabel!
public convenience init() {
self.init(frame: CGRect.zero)
}
public override convenience init(frame: CGRect) {
self.init(internal: nil)
self.frame = frame
}
public required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
fileprivate func commonInit() {
}
}
fileprivate protocol _CustomView {
}
extension CustomView: _CustomView {
}
fileprivate extension _CustomView {
// Protocol extension initializer - has the ability to assign to self, unlike
// class initializers. Note that the name of this initializer can be anything
// you like, here we've called it init(internal:)
init(internal: Int?) {
self = Bundle.main.loadNibNamed("CustomView", owner:nil, options:nil)![0] as! Self;
}
}
class func loadFromNib<T: UIView>() -> T {
let nibName = String(describing: self)
return Bundle.main.loadNibNamed(nibName, owner: nil, options: nil)![0] as! T
}
Swift 4 - 5.1 Protocol Extensions
public protocol NibInstantiatable {
static func nibName() -> String
}
extension NibInstantiatable {
static func nibName() -> String {
return String(describing: self)
}
}
extension NibInstantiatable where Self: UIView {
static func fromNib() -> Self {
let bundle = Bundle(for: self)
let nib = bundle.loadNibNamed(nibName(), owner: self, options: nil)
return nib!.first as! Self
}
}
Adoption
class MyView: UIView, NibInstantiatable {
}
This implementation assumes that the Nib has the same name as the UIView class. Ex. MyView.xib. You can modify this behavior by implementing nibName() in MyView to return a different name than the default protocol extension implementation.
In the xib the files owner is MyView and the root view class is MyView.
Usage
let view = MyView.fromNib()
The most convenient implementation. Here you need two methods, in order to return directly to the object of your class, not UIView.
extension UIView {
class var viewId: String {
return String(describing: self)
}
static func instance(from bundle: Bundle? = nil, nibName: String? = nil,
owner: Any? = nil, options: [AnyHashable : Any]? = nil) -> Self? {
return instancePrivate(from: bundle ?? Bundle.main,
nibName: nibName ?? viewId,
owner: owner,
options: options)
}
private static func instancePrivate<T: UIView>(from bundle: Bundle, nibName: String,
owner: Any?, options: [AnyHashable : Any]?) -> T? {
guard
let views = bundle.loadNibNamed(nibName, owner: owner, options: options),
let view = views.first(where: { $0 is T }) as? T else { return nil }
return view
}
}
Example:
guard let customView = CustomView.instance() else { return }
//Here customView has CustomView class type, not UIView.
print(customView is CustomView) // true
More powerful version based on Logan's answer
extension UIView {
public class func fromNib(nibName: String? = nil) -> Self {
return fromNib(nibName: nibName, type: self)
}
public class func fromNib<T: UIView>(nibName: String? = nil, type: T.Type) -> T {
return fromNib(nibName: nibName, type: T.self)!
}
public class func fromNib<T: UIView>(nibName: String? = nil, type: T.Type) -> T? {
var view: T?
let name: String
if let nibName = nibName {
name = nibName
} else {
name = self.nibName
}
if let nibViews = nibBundle.loadNibNamed(name, owner: nil, options: nil) {
if nibViews.indices.contains(nibIndex), let tog = nibViews[nibIndex] as? T {
view = tog
}
}
return view
}
public class var nibName: String {
return "\(self)".components(separatedBy: ".").first ?? ""
}
public class var nibIndex: Int {
return 0
}
public class var nibBundle: Bundle {
return Bundle.main
}
}
And you can use like
class BaseView: UIView {
override class var nibName: String { return "BaseView" }
weak var delegate: StandardStateViewDelegate?
}
class ChildView: BaseView {
override class var nibIndex: Int { return 1 }
}
let bundle = Bundle(for: type(of: self))
let views = bundle.loadNibNamed("template", owner: self, options: nil)
self.view.addSubview(views?[0] as! UIView)
All you have to do is call init method in your UIView class.
Do it that way:
class className: UIView {
@IBOutlet var view: UIView!
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}
func setup() {
UINib(nibName: "nib", bundle: nil).instantiateWithOwner(self, options: nil)
addSubview(view)
view.frame = self.bounds
}
}
Now, if you want to add this view as a sub view in view controller, do it that way in view controller.swift file:
self.view.addSubview(className())
My contribution:
extension UIView {
class func fromNib<T: UIView>() -> T {
return Bundle(for: T.self).loadNibNamed(String(describing: T.self), owner: nil, options: nil)![0] as! T
}
}
Then call it like this:
let myCustomView: CustomView = UIView.fromNib()
..or even:
let myCustomView: CustomView = .fromNib()
let nibs = Bundle.main.loadNibNamed("YourView", owner: nil, options: nil)
let shareView = nibs![0] as! ShareView
self.view.addSubview(shareView)
If you have a lot of custom views in your project you can create class like UIViewFromNib
Swift 2.3
class UIViewFromNib: UIView {
var contentView: UIView!
var nibName: String {
return String(self.dynamicType)
}
//MARK:
override init(frame: CGRect) {
super.init(frame: frame)
loadViewFromNib()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
loadViewFromNib()
}
//MARK:
private func loadViewFromNib() {
contentView = NSBundle.mainBundle().loadNibNamed(nibName, owner: self, options: nil)[0] as! UIView
contentView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
contentView.frame = bounds
addSubview(contentView)
}
}
Swift 3
class UIViewFromNib: UIView {
var contentView: UIView!
var nibName: String {
return String(describing: type(of: self))
}
//MARK:
override init(frame: CGRect) {
super.init(frame: frame)
loadViewFromNib()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
loadViewFromNib()
}
//MARK:
func loadViewFromNib() {
contentView = Bundle.main.loadNibNamed(nibName, owner: self, options: nil)?[0] as! UIView
contentView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
contentView.frame = bounds
addSubview(contentView)
}
}
And in every class just inherit from UIViewFromNib, also you can override nibName property if .xib file has different name:
class MyCustomClass: UIViewFromNib {
}
I prefer this solution (based on the answer if @GK100):
In SomeView.swift, I loaded the XIB inside the init or init:frame: CGRect initializer. There is no need to assign anything to "self". As soon as the XIB is loaded, all outlets are connected, including the top level view. The only thing missing, is to add the top view to the view hierarchy:
class SomeView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
NSBundle.mainBundle().loadNibNamed("SomeObject", owner: self, options: nil)
self.addSubview(self.view); // adding the top level view to the view hierarchy
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
NSBundle.mainBundle().loadNibNamed("SomeObject", owner: self, options: nil)
self.addSubview(self.view); // adding the top level view to the view hierarchy
}
...
}
Tested in Xcode 7 beta 4 , Swift 2.0 and iOS9 SDK . The following code will assign xib to the uiview. You can able to use this custom xib view in storyboard and access the IBOutlet object also.
import UIKit
@IBDesignable class SimpleCustomView:UIView
{
var view:UIView!;
@IBOutlet weak var lblTitle: UILabel!
@IBInspectable var lblTitleText : String?
{
get{
return lblTitle.text;
}
set(lblTitleText)
{
lblTitle.text = lblTitleText!;
}
}
override init(frame: CGRect) {
super.init(frame: frame)
loadViewFromNib ()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
loadViewFromNib ()
}
func loadViewFromNib() {
let bundle = NSBundle(forClass: self.dynamicType)
let nib = UINib(nibName: "SimpleCustomView", bundle: bundle)
let view = nib.instantiateWithOwner(self, options: nil)[0] as! UIView
view.frame = bounds
view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
self.addSubview(view);
}
}
Access customview programatically
self.customView = SimpleCustomView(frame: CGRectMake(100, 100, 200, 200))
self.view.addSubview(self.customView!);
Source code - https://github.com/karthikprabhuA/CustomXIBSwift
I achieved this with Swift by the following code:
class Dialog: UIView {
@IBOutlet var view:UIView!
override init(frame: CGRect) {
super.init(frame: frame)
self.frame = UIScreen.mainScreen().bounds
NSBundle.mainBundle().loadNibNamed("Dialog", owner: self, options: nil)
self.view.frame = UIScreen.mainScreen().bounds
self.addSubview(self.view)
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
Don't forget to connect your XIB view outlet to view outlet defined in swift. You can also set First Responder to your custom class name to start connecting any additional outlets.
Hope this helps!
Swift 3 version of Logan's answer
extension UIView {
public class func fromNib(nibName: String? = nil) -> Self {
return fromNib(nibName: nibName, type: self)
}
public class func fromNib<T: UIView>(nibName: String? = nil, type: T.Type) -> T {
return fromNib(nibName: nibName, type: T.self)!
}
public class func fromNib<T: UIView>(nibName: String? = nil, type: T.Type) -> T? {
var view: T?
let name: String
if let nibName = nibName {
name = nibName
} else {
name = self.nibName
}
if let nibViews = Bundle.main.loadNibNamed(name, owner: nil, options: nil) {
for nibView in nibViews {
if let tog = nibView as? T {
view = tog
}
}
}
return view
}
public class var nibName: String {
return "\(self)".components(separatedBy: ".").first ?? ""
}
public class var nib: UINib? {
if let _ = Bundle.main.path(forResource: nibName, ofType: "nib") {
return UINib(nibName: nibName, bundle: nil)
} else {
return nil
}
}
}
try following code.
var uiview :UIView?
self.uiview = NSBundle.mainBundle().loadNibNamed("myXib", owner: self, options: nil)[0] as? UIView
Edit:
import UIKit
class TestObject: NSObject {
var uiview:UIView?
init() {
super.init()
self.uiview = NSBundle.mainBundle().loadNibNamed("myXib", owner: self, options: nil)[0] as? UIView
}
}
Building on the above solutions.
This will work across all project bundles and no need for generics when calling fromNib().
Swift 2
extension UIView {
public class func fromNib() -> Self {
return fromNib(nil)
}
public class func fromNib(nibName: String?) -> Self {
func fromNibHelper<T where T : UIView>(nibName: String?) -> T {
let bundle = NSBundle(forClass: T.self)
let name = nibName ?? String(T.self)
return bundle.loadNibNamed(name, owner: nil, options: nil)?.first as? T ?? T()
}
return fromNibHelper(nibName)
}
}
Swift 3
extension UIView {
public class func fromNib() -> Self {
return fromNib(nibName: nil)
}
public class func fromNib(nibName: String?) -> Self {
func fromNibHelper<T>(nibName: String?) -> T where T : UIView {
let bundle = Bundle(for: T.self)
let name = nibName ?? String(describing: T.self)
return bundle.loadNibNamed(name, owner: nil, options: nil)?.first as? T ?? T()
}
return fromNibHelper(nibName: nibName)
}
}
Can be used like this:
let someView = SomeView.fromNib()
Or like this:
let someView = SomeView.fromNib("SomeOtherNibFileName")
A nice way to do this with Swift is to use an enum.
enum Views: String {
case view1 = "View1" // Change View1 to be the name of your nib
case view2 = "View2" // Change View2 to be the name of another nib
func getView() -> UIView? {
return NSBundle.mainBundle().loadNibNamed(self.rawValue, owner: nil, options: nil).first as? UIView
}
}
Then in your code you can simply use:
let view = Views.view1.getView()
Source: Stackoverflow.com