The transform property gives us a way to position and alter elements. It comes in two settings: 2-Dimensional and 3-Dimensional. Each of those comes with different settings and properties, we’ll take a look at both of them in this tutorial.

Syntax-wise, transform property has multiple sub-properties which declare how the element should be transformed. For instance, in the example above, we used the scale property. But there are a number of these like rotate, translate and skew in addition to scale. Let's look at 2D transforms first.

2D Transforms

2D transforms work on x-axis and y-axis, while 3D transforms work on x-axis, y-axis, and z-axis.

Let's look at the four 2D Transform properties:

2D rotate

A preprocessor is a tool that transforms one type of code into another type. In this tutorial, we will look into two popular preprocessors: one for HTML (called Haml) and the other one for CSS (called Sass). Haml and Sass are much more easier to write, and provide a few very useful features out-of-the-box which are not available in HTML or CSS. Thus, by writing in Haml or Sass, and then using a preprocessor to convert your code into HTML or CSS respectively, you can simplify your development process quite a lot.

Haml

Haml stands for HTML abstract markup language. It aims to provide a good structure and makes your HTML code DRY (Don't Repeat Yourself), logical, and easier to read. We will see an example below to see how it does this.

Installation

Basic Authentication

If you were to publish your blog online, anyone would be able to add, edit and delete articles or delete comments.

Rails provides a very simple HTTP authentication system that will work nicely in this situation.

In the ArticlesController we need to have a way to block access to the various actions if the person is not authenticated. Here we can use the Rails http_basic_authenticate_withmethod, which allows access to the requested action if that method allows it.

To use the authentication system, we specify it at the top of our ArticlesController in app/controllers/articles_controller.rb. In our case, we want the user to be authenticated on every action except index and show, so we write that:

class ArticlesController < ApplicationController
   http_basic_authenticate_with name: "dhh", password: "secret", except: [:index, :show]

ES7, officially known as ECMAScript 2016, was finalized in June 2016.

Compared to ES6, ES7 is a tiny release for JavaScript, containing just two features:

• Array.prototype.includes
• Exponentiation Operator

Array.prototype.includes()

This feature introduces a more readable syntax for checking if an array contains an element.

With ES6 and lower, to check if an array contained an element you had to use indexOf, which checks the index in the array, and returns -1 if the element is not there.

Since -1 is evaluated as a true value, you could not do for example

if (![1,2].indexOf(3)) {