Tutorial by Examples: r

Dart allows to easily filter a list using where. var fruits = ['apples', 'oranges', 'bananas']; fruits.where((f) => f.startsWith('a')).toList(); //apples Of course you can use some AND or OR operators in your where clause.

DRF offers the chance to further customize the behavior of the generic views/viewsets by allowing the creation of custom mixins. How to: To define a custom mixin we just need to create a class inheriting from object. Let's assume that we want to define two separate views for a model named MyM...

To make your APK file as small as possible, you should enable shrinking to remove unused code and resources in your release build. This page describes how to do that and how to specify what code and resources to keep or discard during the build. Code shrinking is available with ProGuard, which dete...

An inner class which is visible to any outside class can be created from this class as well. The inner class depends on the outside class and requires a reference to an instance of it. To create an instance of the inner class, the new operator only needs to be called on an instance of the outer cla...

ember install ember-bootstrap

ember generate ember-bootstrap --bootstrap-version=4 --preprocessor=sass

// ember-cli-build.js /* global require, module */ var EmberApp = require('ember-cli/lib/broccoli/ember-app'); module.exports = function(defaults) { var app = new EmberApp(defaults, { // Add options here 'ember-cli-foundation-6-sass': { 'foundationJs': [ ...

{{#bs-form model=this onSubmit=(action "submit") as |form|}} {{#form.element label="Email" placeholder="Email" property="email" as |el|}} <div class="input-group"> <input value={{el.value}} class="form-control" place...

1. Enable Flat Categories and Products One of the top reasons of Magento speed issues with database read speed. To fasten the read speed of the database you should enable Flat Catalog. This will minify the number of database joins done when showing products and due to that the MySQL query complexit...

To discovery all the available print services, we can use the PrintServiceLookup class. Let's see how: import javax.print.PrintService; import javax.print.PrintServiceLookup; public class DiscoveringAvailablePrintServices { public static void main(String[] args) { discoverPrintS...

To discovery the default print service, we can use the PrintServiceLookup class. Let's see how:: import javax.print.PrintService; import javax.print.PrintServiceLookup; public class DiscoveringDefaultPrintService { public static void main(String[] args) { discoverDefaultPrintSer...

A print job is a request of printing something in a specific print service. It consists, basically, by: the data that will be printed (see Building the Doc that will be printed) a set of attributes After picking-up the right print service instance, we can request the creation of a print job...

Doc is an interface and the Java Print Service API provide a simple implementation called SimpleDoc. Every Doc instance is basically made of two aspects: the print data content itself (an E-mail, an image, a document etc) the print data format, called DocFlavor (MIME type + Representation class...

Sometimes we need to determine some aspects of the print request. We will call them attribute. Are examples of print request attributes: amount of copies (1, 2 etc), orientation (portrait or landscape) chromacity (monochrome, color) quality (draft, normal, high) sides (one-sided, two-sided e...

Bottom up approach for printing the nth Fibonacci number using Dynamic Programming. Recursive Tree fib(5) / \ fib(4) fib(3) / \ / \ fib(3) fib(2...

Given 2 string str1 and str2 we have to find the length of the longest common substring between them. Examples Input : X = "abcdxyz", y = "xyzabcd" Output : 4 The longest common substring is "abcd" and is of length 4. Input : X = "zxabcdezy", y = "y...

For example, we can create a ring-shaped cursor fixed to the center of the screen. To fix the cursor to the screen so the cursor is always present no matter where we look, we place it as a child of the active camera entity. We pull it in front of the camera by placing it on the negative Z axis. When...

We’ll first go over gaze-based interactions. Gaze-based interactions rely on rotating our heads and looking at objects to interact with them. This type of interaction is for headsets without a controller. Even with a rotation-only controller (Daydream, GearVR), the interaction is still similar. Sinc...

The cursor primitive is a reticle that allows for clicking and basic interactivity with a scene on devices that do not have a hand controller. The default appearance is a ring geometry. The cursor is usually placed as a child of the camera. <a-scene> <a-camera> <a-cursor>&...

Also known as gaze-based cursor. If we set the cursor to be fuse-based, the cursor will trigger a click if the user gazes at an entity for a set amount of time. Imagine a laser strapped to the user’s head, and the laser extends out into the scene. If the user stares at an entity long enough (i.e., t...