SeamgenKit provides a set of extension methods and helper classes for making iOS development using Swift easier.
Other great Cocoapods:
- SwiftDate - Date utilities
iOS 9.3 or later.
SeamgenKit is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'SeamgenKit', :git => 'https://github.com/seamgen/SeamgenKit-Swift.git'Objects confroming to this protocol can be customized at initialization time. The only requirements is that a class must implement init() or init(frame: CGRect). UIView and NSObject conform to this protocol by default.
let label = UILabel(frame: .zero) {
$0.text = "Hello World"
$0.textAlignment = .center
}
let stackView = UIStackView {
$0.addArrangedSubview(label)
}Simplifies working with Optionals in swift.
// Default empty values
let emptyArray: [Double]? = .emptyValue // []
let emptyDict: [String: Int]? = .emptyValue // [:]
let emptySet: Set<Int>? = .emptyValue // Set([])
let emptyString: String? = .emptyValue // ""
// Check if an object is empty
emptyArray?.isEmpty // true
emptyDict?.isEmpty // true
emptySet?.isEmpty // true
emptyString?.isEmpty // true
// Return nil if the object is empty
let result = emptyString?.nilIfEmpty() // returns nil
// Return an empty value if the object is nil
let nilString: String? = nil
let emptyResult = nilString.valueOrEmpty // returns ""A UIButton subclass that allows positioning of the image view relative to the title label.
A wrapper for converting a remote notification device token to a string representation:
class AppDelegate {
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let token = APNSToken(deviceToken)
print(token.string) // prints "790bc691 eea10194 d80cea25 49d2d8ec 0fb439d1 54242532 db4edecf 97f9e092"
print(token.data) // prints "32 bytes"
}
}Convert to String and Int values:
// To Int:
true.intValue // returns 1
false.intValue // returns 0
// To String:
true.stringValue() // returns "true"
false.stringValue() // returns "false"
// in a specific format:
true.stringValue(as: .yesNo) // returns "yes"
false.stringValue(as: .yN) // returns "n"Or specify your own formats:
extension BoolStringFormatter {
/// Custom "yep" or "nope" formatter.
static let yepNope = BoolStringFormatter(t: "yep", f: "nope")
}
true.stringValue(as: .yepNope) // returns "yep"
false.stringValue(as: .yepNope) // returns "nope"Scale sizes while maintaing aspect ratio:
let size = CGSize(width: 100, height: 50)
let fit = size.scaledTo(fit: CGSize(width: 50, height: 50)) // returns { w: 50, h: 25 }
let fill = size.scaledTo(fill: CGSize(width: 100, height: 100) // returns { w: 200, h: 100 }Simplify delayed async dispatch by making DispatchTime conform to ExpressibleByIntegerLiteral and ExpressibleByFloatLiteral
DispatchQueue.main.asyncAfter(deadline: 5) { ... } // Executes after 5 seconds.Convert any FloatingPoint value to and from radians and degrees:
let radians = 90.0.degreesToRadians // returns 1.5707
let degrees = Double.pi.radiansToDegrees // returns 180Generate a map image with a pin annotation at a given coordinate:
let snapshot = MKMapSnapshot(...)
let coord = CLLocationCoordinate2D(33.132, -117.123)
// Creats the image from the snapshot with the pin annotation at the coordinate.
let image = snapshot.imageWithAnnotation(atCoordinate: coord)Constants have been defined for UILayoutPriority:
/// Use this:
constraint.priority = .high
// instead of:
constraint.priority = UILayoutPriorityDefaultHighAdjust the priority of a constraint inline using withPriority(_:):
button.leftAnchor.constraint(equalTo: view.leftAnchor).withPriority(.required).isActive = trueActivate a constraint inline using activated():
// Assigns and activates the constraint simultaneously:
self.constraint = button.leftAnchor.constraint(equalTo: view.leftAnchor).activated()
// instad of:
let constraint = button.leftAnchor.constraint(equalTo: view.leftAnchor)
constraint.isActive = true
self.constraint = constraintValue conversion from String to Int, Double, Float:
"100".intValue // returns 100
"Foo".intValue // returns 0
"".intValue // returns 0and to Bool. Any number greater than 0 will return true.
// Numbers > 0 return true.
"0".boolValue // returns false
"1".boolValue // returns true
"5".boolValue // returns true
// Case insensitive
"TRue".boolValue // returns true
"true".boolValue // returns true
"yes".boolValue // returns true
"y".boolValue // returns true
// All other values return false.Checking the contents of the string:
"Abc123".containsNumbers // returns true
"Abc123".containsLetters // returns true
"Abc123".isAlphaNumeric // returns true
"Abc123".isNumeric // returns false
"Abc123".isAlphabetic // returns false
"123".isNumeric // returns true
"Abc".isAlphabetic // returns true
"Abc123".numbers // returns "123"
let set = CharacterSet(charactersIn: "bc")
"Abc123".includingCharactersIn(set) // returns "bc"There are convenience methods on UITableView and UICollectionView that simplify registration and dequeueing of cells and supplementary views using the ReusableView protocol.
The old way:
class Cell: UITableViewCell { }
class Header: UITableViewHeaderFooterView { }
tableView.register(Cell.self, forCellReuseIdentifier: "cell")
tableView.register(Header.self, forHeaderFooterViewReuseIdentifier: "header")
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! Cell
let header = tableView.dequeueReusableHeaderFooterView(withIdentifier: "header") as! HeaderThe easier way:
// Conform to ReusableView
class Cell: UITableViewCell, ReusableView { }
class Header: UITableViewHeaderFooterView, ReusableView { }
tableView.register(Cell)
tableView.register(Header)
let cell: Cell = tableView.dequeueCell(for: indexPath)
let header: Header = tableView.dequeueView()Use UIDevice.current to access TouchID helper methods.
To check if TouchID is available:
let result = UIDevice.current.isTouchIDAvailableTo prompt for TouchID authentication:
import LocalAuthentication
UIDevice.current.authenticateWithTouchID("Log In") { success, error in
if let error = error as? LAError {
switch error.code {
case .userCancel:
// Handle user cancellation.
break
default:
// Handle other error types.
break
}
}
// Handle success
}Provides a number of properties for getting information about the current application:
UIApplication.shared.displayName // "My Great App"
UIApplication.shared.version // "1.0"
UIApplication.shared.buildNumber // "33"
UIApplication.shared.bundleIdentifier // "com.seamgen.myGreatApp"
UIApplication.shared.isATSEnabled
// true if ATS has not been explicitly disable in the info.plistAnd provides an easy way to launch the Settings.app by calling:
UIApplication.shared.launchSettingsApp()Convenience property for starting/stopping animation:
let loadingIndicator = UIActivityIndicatorView()
// Use:
loadingIndicator.animate = self.isLoading
// Instead of:
if self.isLoading {
loadingIndicator.startAnimating()
} else {
loadingIndicator.stopAnimating()
}Convenience properties for setting common values for UIControlState.normal:
let button = UIButton()
button.title = "Submit"
button.titleColor = .red
button.attributedTitle = NSAttributedString(...)
button.image = UIImage(...)Create colors from RGBA values or HEX strings:
let rgbColor = UIColor(r: 255, g: 255, b: 255, alpha: 1.0)
let hexColor = UIColor(hex: "#FFF")
let hexColor = UIColor(hex: "#FF00FF") // RGB
let hexColor = UIColor(hex: "#FF00FF55") // RGBACreate a UIImage from a color:
let image = UIImage(color: .red) // returns a 1x1 pixel red image.
let image = UIImage(color: .red, size: CGSize(width: 100, height: 100)) // returns a 100x100
// More options:
let image = UIImage(color: .red,
borderColor: .blue, borderWidth: 2,
cornerRadius: 8, corners: nil,
size: CGSize(width: 100, height: 100))Save an image to disk (as a JPEG)
let image = UIImage(...)
let url = URL(...)
image.writeJPEG(to: url)Scaling
let image = UIImage(...)
let newSize = CGSize(width: 100, height: 100)
// Scale the image to 100x100 without maintaining the aspect ratio.
image.scaledTo(size: newSize)
// Produce an image where both dimensions are < 100. Aspect is maintained.
image.scaledTo(fitSize: newSize)
// Produce an image where the smallest dimension is == 100. Aspect is maintained.
image.scaledTo(fillSize: newSize)Rotation
let image = UIImage(...)
image.rotated(.left) // Rotates the image -90°
image.rotated(.right) // Rotates the image 90°
image.rotated(.byDegrees(30)) // Rotates the image 30°
image.rotated(.byRadians(.pi)) // Rotates the image 180°Fill an image with a color. This method uses the alpha channel as a mask. The result is similar to tinting a template image in a UIImageView.
let image = UIImage(...)
image.filled(with: .red)Add multiple subviews in one line of code:
let v1 = UIView()
let v2 = UIView()
let v3 = UIView()
let viewsToAdd = [v1, v2, v3]
let view = UIView()
let stack = UIStackView()
// Variadic:
view.addSubviews(v1, v2, v3)
stack.addArrangedSubviews(v1, v2, v3)
// or via an array:
view.addSubviews(viewsToAdd)
stack.addArrangedSubviews(viewsToAdd)Methods for presenting basic alerts to the user:
// Display a localized error message to the user with an 'OK' button:
self.presentAlert(withError: error)
self.presentAlert(withError: error, title: "Uh-oh", defaultButtonTitle: "Got It")
// Display a generic alert with a title, message, and button:
self.presentAlert(withTitle: "Account Deleted")
self.presentAlert(withTitle: "Account Deleted", message: "Your account has been deleted.")
self.presentAlert(withTitle: "Account Deleted", message: "Your account has been deleted.", defaultButtonTitle: "OK")
// Present an alert that executes an action when dismissed:
self.presentAlert(withTitle: "Account Deleted", message: nil, defaultButtonTitle: nil) {
// Handle OK button tapped.
}Or present a "Not Implemented" alert to the user if work has not been completed:
// Generic alert:
self.presentNotImplementedAlert()
// More information:
self.presentNotImplementedAlert("Will be implemented in JIRA-12")Methods for creating URLs that launch the native OS applications for phone, email, sms, and maps:
// Dial a phone number:
if let url = URL(phoneCallTo: "760-555-1212") {
UIApplication.shared.openURL(url) // Initiates a phone call.
}
// Compose an Email
if let url = URL(emailTo: "devs@seamgen.com", subject: "SeamgenKit", body: nil, cc: nil) {
UIApplication.shared.openURL(url) // Launches Mail.app
}
// Compose an SMS
if let url = URL(smsTo: "760-555-1212") {
UIApplication.shared.openURL(url) // Launches Messages.app
}Or use the MapURLBuilder for launching the native Maps app:
// View an address:
let url = MapURLBuilder(address: "123 Fake Street San Diego CA, 92101").url
// Execute a search query:
let url = MapURLBuilder(searchFor: "Italian Food").url
// Mark a location with a pin:
let coord = CLLocationCoordinate2D(33.132, -117.123)
let url = MapURLBuilder(pinAt: coord, label: "Seamgen Office"
// Get directions from your current location:
let url = MapURLBuilder(directionsTo: "123 Fake Street", from: nil, transportType: .drive).urlUIApplication also has convenience methods for creating and opening these URLs immediately:
UIApplication.shared.dial("760-555-1212")
UIApplication.shared.composeSMS(to: "760-555-1212")
UIApplication.composeEmail(to: "devs@seamgen.com")Sam Gerardi, sgerardi@seamgen.com
SeamgenKit is available under the MIT license. See the LICENSE file for more info.