How to embed a custom view xib in a storyboard sce

Question

I'm relatively new in the XCode/iOS world; I've done some decent sized storyboard based apps, but I didn't ever cut me teeth on the whole nib/xib thing. I want to use the same tools for scenes to design/layout a reusable view/control. So I created my first ever xib for my view subclass and painted it up:

I have my outlets connected and constraints setup, just like I'm used to doing in the storyboard. I set the class of my File Owner to that of my custom UIView subclass. So I assume I can instantiate this view subclass with some API, and it will configured/connected as shown.

Now back in my storyboard, I want to embed/reuse this. I'm doing so in a table view prototype cell:

I've got a view. I've set the class of it to my subclass. I've created an outlet for it so I can manipulate it.

The $64 question is where/how do I indicate that it's not enough to just put an empty/unconfigured instance of my view subclass there, but to use the .xib I created to configure/instantiate it? It would be really cool, if in XCode6, I could just enter the XIB file to use for a given UIView, but I don't see a field for doing that, so I assume I have to do something in code somewhere.

(I do see other questions like this on SO, but haven't found any asking for just this part of the puzzle, or up to date with XCode6/2015)

Update

I am able to get this to kind of work by implementing my table cell's awakeFromNib as follows:

- (void)awakeFromNib
{
    // gather all of the constraints pointing to the uncofigured instance
    NSArray* progressConstraints = [self.contentView.constraints filteredArrayUsingPredicate: [NSPredicate predicateWithBlock:^BOOL(id each, NSDictionary *_) {
        return (((NSLayoutConstraint*)each).firstItem == self.progressControl) || (((NSLayoutConstraint*)each).secondItem == self.progressControl);
    }]];
    // fetch the fleshed out variant
    ProgramProgressControl *fromXIB = [[[NSBundle mainBundle] loadNibNamed:@"ProgramProgressControl" owner:self options:nil] objectAtIndex:0];
    // ape the current placeholder's frame
    fromXIB.frame = self.progressControl.frame;
    // now swap them
    [UIView transitionFromView: self.progressControl toView: fromXIB duration: 0 options: 0 completion: nil];
    // recreate all of the constraints, but for the new guy
    for (NSLayoutConstraint *each in progressConstraints) {
        id firstItem = each.firstItem == self.progressControl ? fromXIB : each.firstItem;
        id secondItem = each.secondItem == self.progressControl ? fromXIB : each.secondItem;
        NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem: firstItem attribute: each.firstAttribute relatedBy: each.relation toItem: secondItem attribute: each.secondAttribute multiplier: each.multiplier constant: each.constant];
        [self.contentView addConstraint: constraint];
    }
    // update our outlet
    self.progressControl = fromXIB;
}

Is this as easy as it gets then? Or am I working too hard for this?

Answer 1

A little bit more swifty version of @brandonscript 's idea with early return:

override func awakeFromNib() {

    guard let xibName = xibName,
          let xib = Bundle.main.loadNibNamed(xibName, owner: self, options: nil),
          let views = xib as? [UIView] else {
        return
    }

    if views.count > 0 {
        self.addSubview(views[0])
    }

}

Answer 2

The "correct" answer is that you are not meant to make re-usable views with corresponding nibs. If a view subclass is valuable as a reusable object it rarely will need a nib to go with it. Take for example every view subclass provided by UIKit. Part of this thinking is a view subclass that is actually valuable wont be implemented using a nib, which is the general view at Apple.

Usually when you use a view in nib or storyboard you will want to tweak it graphically for the given use case anyway.

You might consider using "copy paste" for recreating same or similar views instead of making separate nibs. I this believe accomplishes the same requirements and it will keep you more or less in line with what Apple is doing.

Answer 3

A pretty cool and reusable way of doing this Interface Builder and Swift 4:

1. Create a new class like so:

   import Foundation
   import UIKit
   
   @IBDesignable class XibView: UIView {
   
       @IBInspectable var xibName: String?
   
       override func awakeFromNib() { 
           guard let name = self.xibName, 
                 let xib = Bundle.main.loadNibNamed(name, owner: self), 
                 let view = xib.first as? UIView else { return }    
           self.addSubview(view)
       }
   
   }
   

2. In your storyboard, add a UIView that will act as the container for the Xib. Give it a class name of XibView:

   

3. In the property inspector of this new XibView, set the name of your .xib (without the file extension) in the IBInspectable field:

   

4. Add a new Xib view to your project, and in the property inspector, set the Xib's "File's Owner" to XibView (ensure you've only set the "File's Owner" to your custom class, DO NOT subclass the content view, or it will crash), and again, set the IBInspectable field:

   

One thing to note: This assumes that you're matching the .xib frame to its container. If you do not, or need it to be resizable, you'll need to add in some programmatic constraints or modify the subview's frame to fit. I use snapkit to make things easy:

xibView.snp_makeConstraints(closure: { (make) -> Void in
    make.edges.equalTo(self)
})

Bonus points

Allegedly you can use prepareForInterfaceBuilder() to make these reusable views visible in Interface Builder, but I haven't had much luck. This blog suggests adding a contentView property, and calling the following:

override func prepareForInterfaceBuilder() {
    super.prepareForInterfaceBuilder()
    xibSetup()
    contentView?.prepareForInterfaceBuilder()
}

Answer 4

• Create xib file File > New > New File > iOS > User Interface > View
• Create custom UIView class File > New > New File > iOS > Source > CocoaTouch
• Assign the xib file's identity to the custom view class
• In viewDidLoad of the view controller initialize the xib and its associated file using loadNibNamed: on NSBundle.mainBundle and the first view returned can be added as a subview of self.view.

• The custom view loaded from the nib can be saved to a property for setting the frame in viewDidLayoutSubviews. Just set the frame to self.view's frame unless you need to make it smaller than self.view.

  class ViewController: UIViewController {
  
      weak var customView: MyView!
  
      override func viewDidLoad() {
          super.viewDidLoad()
          self.customView = NSBundle.mainBundle().loadNibNamed("MyView", owner: self, options: nil)[0] as! MyView
          self.view.addSubview(customView)
          addButtonHandlerForCustomView()
      }
  
      private func addButtonHandlerForCustomView() {
          customView.buttonHandler = {
              [weak self] (sender:UIButton) in
              guard let welf = self else {
                  return
              }
              welf.buttonTapped(sender)
          }
      }
  
      override func viewDidLayoutSubviews() {
          self.customView.frame = self.view.frame
      }
  
      private func buttonTapped(button:UIButton) {
  
      }
  }
  

• Also, if you want to talk back from the xib to your UIViewController instance then create a weak property on the custom view's class.

  class MyView: UIView {
  
      var buttonHandler:((sender:UIButton)->())!
  
      @IBAction func buttonTapped(sender: UIButton) {
          buttonHandler(sender:sender)
      }
  }
  

Here's the project on GitHub