Tutorial by Examples: a

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...

File app.routes Protected routes have canActivate binded to Guard import { provideRouter, Router, RouterConfig, CanActivate } from '@angular/router'; //components import { LoginComponent } from './login/login.component'; import { DashboardComponent } from './dashboard/dashboard.component'; ...

File main.ts (or boot.ts) Consider the examples above: Create the guard (where the Guard is created) and Add guard to route configuration, (where the Guard is configured for route, then APP_ROUTER_PROVIDERS is exported), we can couple the bootstrap to Guard as follows import { bootstrap }...

You can use the ** keyword argument unpacking operator to deliver the key-value pairs in a dictionary into a function's arguments. A simplified example from the official documentation: >>> >>> def parrot(voltage, state, action): ... print("This parrot wouldn't", ac...

Consider the following dictionaries: >>> fish = {'name': "Nemo", 'hands': "fins", 'special': "gills"} >>> dog = {'name': "Clifford", 'hands': "paws", 'color': "red"} Python 3.5+ >>> fishdog = {**fish, **dog}...

Create an interface decorated with a ServiceContract attribute and member functions decorated with the OperationContract attribute. namespace Service { [ServiceContract] interface IExample { [OperationContract] string Echo(string s); } } Create a concrete...

$(window).load() was deprecated in jQuery version 1.8 (and completely removed from jQuery 3.0) and as such should not be used anymore. The reasons for the deprecation are noted on the jQuery page about this event Caveats of the load event when used with images A common challenge developers attem...

Two ways to replace: by regex or by exact match. Note: the original String object will be unchanged, the return value holds the changed String. Exact match Replace single character with another single character: String replace(char oldChar, char newChar) Returns a new string resulting from...

There are two kinds of boolean operators in Elixir: boolean operators (they expect either true or false as their first argument) x or y # true if x is true, otherwise y x and y # false if x is false, otherwise y not x # false if x is true, otherwise true All of booleans...

Equality: value equality x == y (1 == 1.0 # true) value inequality x == y (1 != 1.0 # false) strict equality x === y (1 === 1.0 # false) strict inequality x === y (1 !== 1.0 # true) Comparison: x > y x >= y x < y x <= y If types are compatible, comparison uses natural o...

An explicit intent is used for starting an activity or service within the same application package. In this case the name of the intended class is explicitly mentioned: Intent intent = new Intent(this, MyComponent.class); startActivity(intent); However, an implicit intent is sent across the sys...

Pretty much every header file should follow the include guard idiom: my-header-file.h #ifndef MY_HEADER_FILE_H #define MY_HEADER_FILE_H // Code body for header file #endif This ensures that when you #include "my-header-file.h" in multiple places, you don't get duplicate declara...

Router enables navigation from one view to another based on user interactions with the application. Following are the steps in implementing basic routing in Angular 2 - Basic precaution: Ensure you have the tag <base href='/'> as the first child under your head tag in your index.htm...

functions.php: // We add the action twice, once for logged in users and once for non logged in users. add_action( 'wp_ajax_my_action', 'my_action_callback' ); add_action( 'wp_ajax_nopriv_my_action', 'my_action_callback' ); // Enqueue the script on the front end. add_action( 'wp_enqueue_script...

Attach an Event Handler Since version 1.7 jQuery has the event API .on(). This way any standard javascript event or custom event can be bound on the currently selected jQuery element. There are shortcuts such as .click(), but .on() gives you more options. HTML <button id="foo">b...

Let's start with example. Here is a very simple example HTML. Example HTML <html> <head> </head> <body> <ul> <li> <a href="some_url/">Link 1</a> </li> &l...

If you want your script to wait until a certain resource was loaded, such as an image or a PDF you can use .load(), which is a shortcut for shortcut for .on( "load", handler). HTML <img src="image.jpeg" alt="image" id="image"> jQuery $( "#imag...

You can create a UIColor from a hexadecimal number or string, e.g. 0xff00cc, "#FFFFFF" Swift Int Value extension UIColor { convenience init(hex: Int, alpha: CGFloat = 1.0) { let r = CGFloat((hex >> 16) & 0xff) / 255 let g = CGFloat((hex >> 08) &amp...

When you need to iterate over the list of jQuery elements. Consider this DOM structure: <div class="container"> <div class="red one">RED 1 Info</div> <div class="red two">RED 2 Info</div> <div class="red three"...

For the character entity character(len=5), parameter :: greeting = "Hello" a substring may be referenced with the syntax greeting(2:4) ! "ell" To access a single letter it isn't sufficient to write greeting(1) ! This isn't the letter "H" but greeting(1:...