Tutorial by Examples: control

Swift let alert = UIAlertController(title: "Hello", message: "Welcome to the world of iOS", preferredStyle: UIAlertControllerStyle.alert) let defaultAction = UIAlertAction(title: "OK", style: UIAlertActionS...

With UIAlertController, action sheets like the deprecated UIActionSheet are created with the same API as you use for AlertViews. Simple Action Sheet with two buttons Swift let alertController = UIAlertController(title: "Demo", message: "A demo with two buttons", preferredStyle...

In this example we aim to accomplish one of the most common tasks: I have a small DC motor laying around, how do I use my Arduino to control it? Easy, with PWM and serial communication, using the function analogWrite() and the Serial library. The basics Pulse Width Modulation or PWM for short is a...

class UsersController < ApplicationController def index respond_to do |format| format.html { render html: "Hello World" } end end end This is a basic controller, with the addition of the following route (in routes.rb): resources :users, only: [:index] Will...

To set up a controller with user authentication using devise, add this before_action: (assuming your devise model is 'User'): before_action :authenticate_user! To verify if a user is signed in, use the following helper: user_signed_in? For the current signed-in user, use this helper: current_us...

Using the Control.Invoke() method you may move the execution of a method or function from a background thread to the thread that the control was created on, which is usually the UI (User Interface) thread. By doing so your code will be queued to run on the control's thread instead, which removes the...

Once registered a dependency can be retrieved by adding parameters on the Controller constructor. // ... using System; using Microsoft.Extensions.DependencyInjection; namespace Core.Controllers { public class HomeController : Controller { public HomeController(ITestServic...

Usually authentication&authorization processes are performed by built-in cookie and token supports in .net MVC. But if you decide to do it yourself with Session you can use below logic for both page requests and ajax requests. public class SessionControl : ActionFilterAttribute { public o...

Instead of requesting an ILoggerFactory and creating an instance of ILogger explicitly, you can request an ILogger (where T is the class requesting the logger). public class TodoController : Controller { private readonly ILogger _logger; public TodoController(ILogger<TodoController...

While it might seem counterintuitive, you can use logical operators to determine whether or not a statement is run. For instance: File.exist?(filename) or STDERR.puts "#{filename} does not exist!" This will check to see if the file exists and only print the error message if it doesn't....

class PostsController < ApplicationController before_action :set_post, only: [:show, :edit, :update, :destroy] def index @posts = Post.all end def show end def new @post = Post.new end def edit end def create @post = Post.new(post_par...

Accessibility of symbols declared in a module can be controlled using private and public attributes and statement. Syntax of the statement form: !all symbols declared in the module are private by default private !all symbols declared in the module are public by default public !symbols in t...

There is no need to create the whole UI in a single FXML using a single controller. The <fx:include> tag can be used to include one fxml file into another. The controller of the included fxml can be injected into the controller of the including file just as any other object created by the FXM...

The below examples use the new form API introduced in RC3. pw-change.template.html <form class="container" [formGroup]="pwChangeForm"> <label for="current">Current Password</label> <input id="current" formControlName="curr...

The control directive is used with the user controls and appears in the user control (.ascx) files. The basic syntax of Control directive is: <%@ Control Language="C#" EnableViewState="false" %> The attributes of the Control directive are: AttributesDescriptionAutoEv...

The default Angular router allows navigation to and from any route unconditionally. This is not always the desired behavior. In a scenario where a user may conditionally be allowed to navigate to or from a route, a Route Guard may be used to restrict this behavior. If your scenario fits one of the...

Common page and control events are: DataBinding - It is raised when a control binds to a data source. Disposed - It is raised when the page or the control is released. Error - It is a page event, occurs when an unhandled exception is thrown. Init - It is raised when the page or the control is in...

PHP provides an alternative syntax for some control structures: if, while, for, foreach, and switch. When compared to the normal syntax, the difference is, that the opening brace is replaced by a colon (:) and the closing brace is replaced by endif;, endwhile;, endfor;, endforeach;, or endswitch;, ...

Loop control statements are used to change the flow of execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed. The break and continue are loop control statements. The break statement terminates a loop without any furthe...

Now we'll try going for a little more complex example, using the capabilities of the controller to fill in the view. Here is our view: /application/views/hello_world.php <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <titl...