amlcurran

05-24 17:44:17.270    1388-1388/com.amlcurran.messages D/StrictMode﹕ StrictMode policy violation; ~duration=233 ms: android.os.StrictMode$StrictModeDiskReadViolation: policy=2335 violation=2
            at android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:1135)
            at libcore.io.BlockGuardOs.open(BlockGuardOs.java:106)
            at libcore.io.IoBridge.open(IoBridge.java:393)
            at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
            at java.io.FileOutputStream.<init>(FileOutputStream.java:73)
            at com.android.server.pm.Settings.writePackageRestrictionsLPr(Settings.java:1062)
            at com.android.server.pm.PackageManagerService.findPreferredActivity(PackageManagerService.java:3086)
            at com.android.server.pm.PackageManagerService.chooseBestActivity(PackageManagerService.java:2945)
            at com.android.server.pm.PackageManagerService.resolveIntent(PackageManagerService.java:2886)

amlcurran

<link rel="import" href="../core-icon-button/core-icon-button.html">
<link rel="import" href="../core-toolbar/core-toolbar.html">
<link rel="import" href="../core-header-panel/core-header-panel.html">

<polymer-element name="my-element">

  <template>
    <style>    
      :host {
        position: absolute;

amlcurran

class FirstViewController: UIViewController, UITableViewDelegate {
    
    private let items : [String] = [ /* some items */]
    private let tableView = UITableView()
    
    /* lots of other methods */
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        tableView.delegate = self

amlcurran

class FirstViewController: UIViewController, UITableViewDelegate {
    
    private let items : [String] = [ /* some items */]
    private let tableView = UITableView()
    
    /* lots of other methods */
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        tableView.delegate = self

amlcurran

class FirstViewController: UIViewController {
    
    private let items : [String] = [ /* some items */]
    private let tableView = UITableView()
    
    /* lots of other methods */
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        tableView.delegate = self

amlcurran

class FirstViewController: UIViewController {
    
    private let items : [String] = [ /* some items */]
    private let tableView = UITableView()
    private var delegate : UITableViewDelegate!
    
    /* lots of other methods */
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)

amlcurran

var string: String = "hello"
string = nil // fails to compile - trying to assign nil to a non-optional value

var optionalString: String? = "hello"
optionalString = nil // compiles fine, as we've declared this to be an optional string

amlcurran

let optionalString: String? = nil

let count = optionalString?.utf8.count // count is an optional Int

amlcurran

func doSomething(optionalString: String?) {
  if let string = optionalString {
    let count = string.utf8.count // string is not optional and can be used normally
  }
}

func doSomething(optionalString: String?) {
  guard let string = optionalString else {
    // this closure is called if optionalString was nil
    return

amlcurran

// this is less descriptive and more difficult to read
if (user.getState() == LoginState.LOGGED_IN && articleList.getQueue().size() > 0) {
  uploadArticles();
}

// this is much easier to read and know what's happening
if (user.isLoggedIn() && articleList.hasQueuedArticles()) {
  uploadArticles();
}