R.swift/Documentation/Examples.md

Examples

On this page you'll find examples of the kind of resources R.swift supports and how you can use them. We aim to keep this page up to date and complete so this should be a overview of all possibilities.

Runtime validation

Call R.assertValid() to call all validation methods that R.swift generates, this will check:

• If all images used in storyboards are available
• If all view controllers with storyboard identifiers can be loaded

The assertValid() method does nothing when in release mode, only in debug mode it will perform checks and assert if a check fails. If you want more control you can also use try R.validate() which will throw a detailed error about the problems that occur and will always perform checks, even in release builds.

Note: The validation methods are there to perform checks that can't be done at compile time, it's recommended to put R.assertValid() in your AppDelegate.

Images

R.swift will find both images from Asset Catalogs and image files in your bundle.

Vanilla

let settingsIcon = UIImage(named: "settings-icon")
let gradientBackground = UIImage(named: "gradient.jpg")

With R.swift

let settingsIcon = R.image.settingsIcon()
let gradientBackground = R.image.gradientJpg()

Custom fonts

Vanilla

let lightFontTitle = UIFont(name: "Acme-Light", size: 22)

With R.swift

let lightFontTitle = R.font.acmeLight(size: 22)

Resource files

Vanilla

let jsonURL = NSBundle.mainBundle().URLForResource("seed-data", withExtension: "json")
let jsonPath = NSBundle.mainBundle().pathForResource("seed-data", withExtension: "json")

With R.swift

let jsonURL = R.file.seedDataJson()
let jsonPath = R.file.seedDataJson.path()

Colors

Vanilla

label.backgroundColor = UIColor(red: 0.9, green: 0.9, blue: 0.9, alpha: 0.5)
label.textColor = UIColor(red: 0.3, green: 0.3, blue: 0.3, alpha: 1.0)

With R.swift

// Colors are extracted from the *.clr files that are in your Xcode project
label.backgroundColor = R.color.appColors.backgroundColor()
label.textColor = R.color.appColors.textColor()

There are some points to keep in mind when using Color palettes, see About Colors

Localized strings

Vanilla

let welcomeMessage = NSLocalizedString("welcome.message", comment: "")
let settingsTitle = NSLocalizedString("title", tableName: "Settings", comment: "")

// Formatted strings
let welcomeName = String(format: NSLocalizedString("welcome.withName", comment: ""), locale: NSLocale.currentLocale(), "Alice")

// Stringsdict files
let progress = String(format: NSLocalizedString("copy.progress", comment: ""), locale: NSLocale.currentLocale(), 4, 23)

With R.swift

// Localized strings are grouped per table (.strings file)
let welcomeMessage = R.string.localizable.welcomeMessage()
let settingsTitle = R.string.settings.title()

// Functions with parameters are generated for format strings
let welcomeName = R.string.localizable.welcomeWithName("Alice")

// Functions with named argument labels are generated for stringsdict keys
let progress = R.string.localizable.copyProgress(completed: 4, total: 23)

Storyboards

Vanilla

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let initialTabBarController = storyboard.instantiateInitialViewController() as? UITabBarController
let settingsController = self.instantiateViewControllerWithIdentifier("settingsController") as? SettingsController

With R.swift

let storyboard = R.storyboard.main()
let initialTabBarController = R.storyboard.main.initialViewController()
let settingsController = R.storyboard.main.settingsController()

Segues

Vanilla

// Trigger segue with:
performSegueWithIdentifier("openSettings", sender: self)

// And then prepare it:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
  if let settingsController = segue.destinationViewController as? SettingsController,
    segue = segue as? CustomSettingsSegue
    where segue.identifier == "openSettings" {
      segue.animationType = .LockAnimation
      settingsController.lockSettings = true
  }
}

With R.swift

// Trigger segue with:
performSegueWithIdentifier(R.segue.overviewController.openSettings, sender: self)

// And then prepare it:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
  if let typedInfo = R.segue.overviewController.openSettings(segue: segue) {
    typedInfo.segue.animationType = .LockAnimation
    typedInfo.destinationViewController.lockSettings = true
  }
}

Tip: Take a look at the SegueManager library, it makes segues block based and is compatible with R.swift.

Nibs

Vanilla

let nameOfNib = "CustomView"
let customViewNib = UINib(nibName: "CustomView", bundle: nil)
let rootViews = customViewNib.instantiateWithOwner(nil, options: nil)
let customView = rootViews[0] as? CustomView

let viewControllerWithNib = CustomViewController(nibName: "CustomView", bundle: nil)

With R.swift

let nameOfNib = R.nib.customView.name
let customViewNib = R.nib.customView()
let rootViews = R.nib.customView.instantiateWithOwner(nil)
let customView = R.nib.customView.firstView(owner: nil)

let viewControllerWithNib = CustomViewController(nib: R.nib.customView)

Reusable table view cells

Vanilla

class FaqAnswerController: UITableViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    let textCellNib = UINib(nibName: "TextCell", bundle: nil)
    tableView.registerNib(textCellNib, forCellReuseIdentifier: "TextCellIdentifier")
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let textCell = tableView.dequeueReusableCellWithIdentifier("TextCellIdentifier", forIndexPath: indexPath) as! TextCell
    textCell.mainLabel.text = "Hello World"
    return textCell
  }
}

With R.swift

class FaqAnswerController: UITableViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    tableView.registerNib(R.nib.textCell)
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let textCell = tableView.dequeueReusableCellWithIdentifier(R.nib.textCell.identifier, forIndexPath: indexPath)!
    textCell.mainLabel.text = "Hello World"
    return textCell
  }
}

Reusable collection view cells

Vanilla

class RecentsController: UICollectionViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    let talkCellNib = UINib(nibName: "TalkCell", bundle: nil)
    collectionView?.registerNib(talkCellNib, forCellWithReuseIdentifier: "TalkCellIdentifier")
  }

  override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("TalkCellIdentifier", forIndexPath: indexPath) as! TalkCell
    cell.configureCell("Item \(indexPath.item)")
    return cell
  }
}

With R.swift

class RecentsController: UICollectionViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    collectionView?.registerNib(R.nib.talkCell)
  }

  override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(R.reuseIdentifier.talkCell, forIndexPath: indexPath)!
    cell.configureCell("Item \(indexPath.item)")
    return cell
  }
}