Using anchors to match a parent view's constraints

Swift extensions are really great, including when working with Auto Layout. We can make a child view fill its superview using constraints, as well as having insets between them. This is very useful when adding a child view controller to its parent within a subview.

extension UIView {
    func attachAnchors(to view: UIView, with insets: UIEdgeInsets = .zero) {
        NSLayoutConstraint.activate([
            topAnchor.constraint(equalTo: view.topAnchor, constant: insets.top),
            rightAnchor.constraint(equalTo: view.rightAnchor, constant: -insets.right),
            bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -insets.bottom),
            leftAnchor.constraint(equalTo: view.leftAnchor, constant: insets.left)
        ])
    }
}

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Thanks for reading and happy coding!

Hi, I hope you enjoyed the article. I am Andrew - a builder of apps and developer tools. Articles on the blog focus on all aspects of Android and iOS development using Kotlin and Swift.

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