Tutorial by Examples: d

Media queries have an optional mediatype parameter. This parameter is placed directly after the @media declaration (@media mediatype), for example: @media print { html { background-color: white; } } The above CSS code will give the DOM HTML element a white background color wh...

Any predicate function can be used as a spec. Here's a simple example: (clojure.spec/valid? odd? 1) ;;=> true (clojure.spec/valid? odd? 2) ;;=> false the valid? function will take a spec and a value and return true if the value conforms to the spec and false otherwise. One other inte...

Let's say we have the following function: (defn nat-num-count [nums] (count (remove neg? nums))) We can write a spec for this function by defining a function spec of the same name: (clojure.spec/fdef nat-num-count :args (s/cat :nums (s/coll-of number?)) :ret integer? ...

Hibernate can use two types of fetch when you are mapping the relationship between two entities: EAGER and LAZY. In general, the EAGER fetch type is not a good idea, because it tells JPA to always fetch the data, even when this data is not necessary. Per example, if you have a Person entity and th...

Suppose we have an interface: interface IPerson { name: string; age: number; breath(): void; } And we want to create more specific interface that has the same properties of the person, we can do it using the extends keyword: interface IManager extends IPerson { managerId:...

The ng-show directive shows or hides the HTML element based on if the expression passed to it is true or false. If the value of the expression is falsy then it will hide. If it is truthy then it will show. The ng-hide directive is similar. However, if the value is falsy it will show the HTML elemen...

Install jquery via npm : npm install jquery --save Install typings for the library: To add typings for a library, do the following: typings install jquery --global --save Add jquery to angular-cli-build.js file to vendorNpmFiles array: This is required so the build system...

An example XML file <Sample> <Account> <One number="12"/> <Two number="14"/> </Account> <Account> <One number="14"/> <Two number="16"/> </Account&gt...

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...

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...

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...