Tutorial by Examples: e

we can create a new controller with rails g controller command. $ bin/rails generate controller controller_name The controller generator is expecting parameters in the form of generate controller ControllerName action1 action2. The following creates a Greetings controller with an action of hell...

public class App : Application { internal static NavigationPage NavPage; public App () { // The root page of your application MainPage = new RootPage(); } } public class RootPage : MasterDetailPage { public RootPage() { var menuPage = ne...

You can use re.finditer to iterate over all matches in a string. This gives you (in comparison to re.findall extra information, such as information about the match location in the string (indexes): import re text = 'You can try to find an ant in this string' pattern = 'an?\w' # find 'an' either w...

The Windows API GetTickCount function returns the number of milliseconds since the system (computer) was started. The simplest example follows: var Start, Stop, ElapsedMilliseconds: cardinal; begin Start := GetTickCount; // do something that requires measurement Stop := GetTickCount; ...

Appearance : Trying to access an array by a key that does not exist in the array Possible Solution : Check the availability before accessing it. Use: isset() array_key_exists()

Appearance : Happens when your script tries to send a HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client. Possible Causes : Print, echo: Output from print and echo statements will terminate the opportunity to send HTTP hea...

Detailed instructions on adding the required Camel dependencies. Maven Dependency One of the most common ways to include Apache Camel in your application is through a Maven dependency. By adding the dependency block below, Maven will resolve the Camel libraries and dependencies for you. <dep...

Assume an application with a MainActivity which can call the Next Activity using a button click. public class MainActivity extends AppCompatActivity { private final String LOG_TAG = MainActivity.class.getSimpleName(); @Override protected void onCreate(Bundle savedInstanceState) { ...

The below code example will give you an adjusted version of that color where a higher percentage will be brighter and a lower percentage will be darker. Objective-C + (UIColor *)adjustedColorForColor:(UIColor *)c : (double)percent { if (percent < 0) percent = 0; CGFloat r, g, b...

Pan gesture recognizers detect dragging gestures. The following example adds an image to a view controller and lets the user drag it around on screen. Objective-C - (void)viewDidLoad { [super viewDidLoad]; UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNa...

Premise The most confusing thing surrounding pointer syntax in C and C++ is that there are actually two different meanings that apply when the pointer symbol, the asterisk (*), is used with a variable. Example Firstly, you use * to declare a pointer variable. int i = 5; /* 'p' is a pointer to a...

Without Auto Layout, animation is accomplished changing a view's frame over time. With Auto Layout, the constraints dictate the view frame, so you have to animate the constraints instead. This indirection makes animation harder to visualize. Here are the ways to animate with Auto Layout: Change ...

When performing tasks asynchronously there typically becomes a need to ensure a piece of code is run on the main thread. For example you may want to hit a REST API asynchronously, but put the result in a UILabel on the screen. Before updating the UILabel you must ensure that your code is run on th...

Avoid code repetition in constructors by setting a tuple of variables with a one liner: class Contact: UIView { private var message: UILabel private var phone: UITextView required init?(coder aDecoder: NSCoder) { (message, phone) = self.dynamicType.setUp() su...

let mySwitch: UISwitch = { view.addSubview($0) $0.addTarget(self, action: "action", forControlEvents: .TouchUpInside) return $0 }(UISwitch())

@IBOutlet weak var title: UILabel! { didSet { label.textColor = UIColor.redColor() label.font = UIFont.systemFontOfSize(20) label.backgroundColor = UIColor.blueColor() } } It's also possible to both set a value and initialize it: private var loginButton = UIButton() { ...

Move every outlet to an NSObject. Then drag an Object from the library to the controller scene of the storyboard and hook the elements there. class ContactFormStyle: NSObject { @IBOutlet private weak var message: UILabel! { didSet { message.font = UIFont.systemFontOfSize(12) ...

This is similar in syntax to the example that initializes using positional constants, but requires the Then extension from https://github.com/devxoul/Then (attached below). let label = UILabel().then { $0.textAlignment = .Center $0.textColor = UIColor.blackColor( $0.text = "Hell...

//Swift let storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) //Objective-c UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]];

//Swift let initialScreen = storyboard.instantiateInitialViewController() //Objective-c UIViewController *initailScreen = [storyboard instantiateInitialViewController];