How to initialize/instantiate a custom UIView class with a XIB file in Swift

Sam's solution is already great, despite it doesn't take different bundles into account (NSBundle:forClass comes to the rescue) and requires manual loading, a.k.a typing code.

If you want full support for your Xib Outlets, different Bundles (use in frameworks!) and get a nice preview in Storyboard try this:

// NibLoadingView.swift
import UIKit

/* Usage: 
- Subclass your UIView from NibLoadView to automatically load an Xib with the same name as your class
- Set the class name to File's Owner in the Xib file
*/

@IBDesignable
class NibLoadingView: UIView {

    @IBOutlet weak var view: UIView!

    override init(frame: CGRect) {
        super.init(frame: frame)
        nibSetup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        nibSetup()
    }

    private func nibSetup() {
        backgroundColor = .clearColor()

        view = loadViewFromNib()
        view.frame = bounds
        view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        view.translatesAutoresizingMaskIntoConstraints = true

        addSubview(view)
    }

    private func loadViewFromNib() -> UIView {
        let bundle = NSBundle(forClass: self.dynamicType)
        let nib = UINib(nibName: String(self.dynamicType), bundle: bundle)
        let nibView = nib.instantiateWithOwner(self, options: nil).first as! UIView

        return nibView
    }

}

Use your xib as usual, i.e. connect Outlets to File Owner and set File Owner class to your own class.

Usage: Just subclass your own View class from NibLoadingView & Set the class name to File's Owner in the Xib file

No additional code required anymore.

Credits where credit's due: Forked this with minor changes from DenHeadless on GH. My Gist: https://gist.github.com/winkelsdorf/16c481f274134718946328b6e2c9a4d8

I tested this code and it works great:

class MyClass: UIView {        
    class func instanceFromNib() -> UIView {
        return UINib(nibName: "nib file name", bundle: nil).instantiateWithOwner(nil, options: nil)[0] as UIView
    }    
}

Initialise the view and use it like below:

var view = MyClass.instanceFromNib()
self.view.addSubview(view)

OR

var view = MyClass.instanceFromNib
self.view.addSubview(view())

UPDATE Swift >=3.x & Swift >=4.x

class func instanceFromNib() -> UIView {
    return UINib(nibName: "nib file name", bundle: nil).instantiate(withOwner: nil, options: nil)[0] as! UIView
}