Drawing custom view in Interface Builder, and loading it in code

I am kind of ashamed that after all this time I still get this stuff wrong, so here’s the memo post. To make up for my silliness the code is in Swift 👍.

Drawing a custom view in Interface Builder

The workflow to draw a custom view in IB in it’s own .xib is the same you would use when dealing with scene subview in a Storyboard, mainly drag and drop stuff.

The important thing to keep in mind is that the subviews need to be connected to the outlets of the view itself, rather than the file owner, as one would usually do when working on a view controller.

Loading the image from code

To get an instance of the custom view via code you cannot simply call initWithFrame:, because that wouldn’t load the content of the .xib in the view.

This is how you can get an instance of custom view drawn in Interface Builder:

let view = NSBundle.mainBundle().loadNibNamed("View", owner: self, options: nil).first as! UIView

Usually this code would be called either from a view or a view controller, which is the owner: self parameter.

Also note the as! forced unwrap. We can do that because we are sure, or at least should be, that the main bundle contains a nib named View.