Learn Alpine, Nightmare and Ruby

Welcome to this beginner level series on Alpine JS! 👋🏞

Alpine JS is a rugged, minimal framework for composing JavaScript behaviour in your markup. It brings declarative, reactive, data-driven nature of libraries like React or Vue to your HTML templates.

In this series, you will learn about Alpine's handy **directives**. You'll discover how to define a component scope with `x-data`, run code on mount with `x-init`, attach event listeners with `x-on`, display data with `x-text`, decide wether or not to show an element with `x-show`, iterate through data with `x-for`, retrieve a DOM element with `x-ref`, learn how to achieve _two-way data binding_ with `x-model`, and much more.

You'll also learn how **"modifiers"** can be applied and chained to directives to provide additional functionality: control the animation transition of entering and leaving DOM elements, debounce an event listener, etc.

We'll also touch on what Alpine calls **"magic properties"**, which give you access to native browser events (`$event`), reference to DOM elements (`$refs`), and more.

You'll gradually discover Alpine's API and syntax, from building simple tabs to a mini app that fetches a dog picture based on a "breed" search field. 🐶

**Get ready to breathe some fresh air** - it's time to walk into cool, green Alpine pastures! 🏞

Alpine.js offers you the reactive and declarative nature of big frameworks like Vue or React at a much lower cost.

You get to keep your DOM, and sprinkle in behavior as you see fit.

alpine

Sprinkle declarative, reactive behaviour on your HTML with Alpine JS

Rails is a web-application framework that includes everything needed to create database-backed web applications according to the Model-View-Controller (MVC) pattern.

rails

Expanding on [Part 1](https://egghead.io/lessons/angularjs-rails-todo-api-part-1), this lesson will look at how to bootstrap AngularJS in a rails application as part of the asset pipeline. With Angular available, you'll see how to communicate with the Rails API using $resource.

Rails Todo API Part 2

AngularJS is an open-source JavaScript framework, maintained by Google, that assists with running single-page applications. Its goal is to augment web-based applications with model–view–controller (MVC) capability, in an effort to make both development and testing easier.

angularjs

Rails makes an excellent choice for delivering data to AngularJS via REST apis. In this first lesson of a two part series, you'll see how to create a simple API for CRUD operations on TODOs using Rails. This isn't an introduction to Rails, and assumes you know the basics. 

Rails Todo API Part 1

Nightmare is a high-level browser automation library.

The goal is to expose just a few simple methods, and have an API that feels synchronous for each block of scripting, rather than deeply nested callbacks. It's designed for automating tasks across sites that don't have APIs.

nightmare

Many pages you'll want to grab data from will require you to log in first. This video demonstrates how to log in and grab whatever data off the page you will need.

Scraping Data from Sites with Login Forms with Nightmare

Many websites have more than just simple static content. Dynamic content which is rendered by JavaScript requires browser to be able to scrape data. This video demonstrates how to use Nightmare (which is a wrapper around Electron) to launch a url and scrape dynamic data.

Scraping Dynamic JavaScript Websites with Nightmare

Create a search directive with AngularJS and Rails. You'll want to take a look at the related [Rails TODO API Part 1](https://egghead.io/lessons/angularjs-rails-todo-api-part-1) and [Rails TODO API Part 2](https://egghead.io/lessons/angularjs-rails-todo-api-part-2). This is **not** a Rails how-to, so some knowledge there is expected to get up and running.

Search Directive with Rails

Jekyll is a parsing engine bundled as a ruby gem used to build static websites from dynamic components such as templates, partials, liquid code, markdown, etc. Jekyll is known as "a simple, blog aware, static site generator".

jekyll

[Jekyll](https://jekyllrb.com/) is a static site generator built in [Ruby](https://www.ruby-lang.org/en/) and available to generate and host websites on [GitHub Pages](https://pages.github.com/). In this course, you'll install the Jekyll gem, use the command line tool to generate a new project, inspect the scaffolded project, and finally, serve the starter website.

Install Jekyll and generate initial, scaffolded website

In this lesson, we define a "count" state value with the `x-data` directive provided by Alpine JS. This defines a new scoped component, which can have access to this state.

We then display the "count" value in our HTML with the `x-text` directive, which updates an element's `innerText` value.

We also hook up buttons with click event listeners with `x-on:click`, which allows us to modify the count value as desired.

Update a count state value with the x-on event listener directive in Alpine JS

In this lesson, we create a set of tabs with Alpine JS, where only the content of the currently active tab is visible. To do this, we define an `activeTab` state value with `x-data. We then wire up our buttons to change the value of `activeTab` on click, and use `x-show` to determine if the tab content should be visible or not, based on the value of `activeTab`.

We also take control of the `class` attribute with `x-bind`, and we conditionally output an "active" class based on, you guessed it, the value of `activeTab`.

Toggle visibility and styles based on state with `x-show` and `x-bind` in Alpine JS

In this lesson, we move the component definition to a function, defined in a script tag in the HTML document.

We then iterate through an Array of Objects with the `x-for` directive in Alpine JS. We use a `<template>` tag to wrap the HTML element we want to repeat for each item, and put the `x-for` directive on that template tag.

We also define a "computed" property by adding a method on our function, which checks if a given ID matched the currently active tab id. This computed property allows us to determine wether or not to apply the "active" classname to our tab buttons.

Iterate through data with the `x-for` attribute in Alpine JS

In this lesson, we smoothen the transitions between tabs by applying a `transition` modifier to our `x-show` directive.

We see how we can ignore the leaving elements, and focus the animation on the entering elements. We tweak the transition duration and origin by chaining additional modifiers to our `x-show` directive.

Control enter and leave transitions with the `x-show.transition` modifier in Alpine JS

In this lesson, we see how the `x-model` directive makes achieving "two-way data binding" effortless in Alpine JS.

We see what it would take to recreate the same functionality with an `x-bind` directive for the input value, as well as an `@input` event listener which, thanks to an access to the browser's native events via the `$event` magic property, sets the state value to `$event.target.value`.

Keep a DOM input and state value in sync with the `x-model` directive in Alpine JS

In this lesson, we learn how to retrieve a DOM element via the `x-ref` directive in Alpine JS, which gives us a reference to the element it is applied on. In our case, an input field.

We can then use the `$refs` object, and reach for the ref we need to target.

This allows us to trigger the focus state of the input field, with the `.focus()` method.

Focus an input field on button click with `x-ref` and the `$refs` property in Alpine JS

In this lesson, we learn how the `x-init` directive in Alpine JS lets us run a JavaScript expression once the component has initiated.

We see the nuances that allow us to trigger that code before Alpine performs initial DOM updates, or after these updates have been made.

Focus in input field on page load with `x-init` in Alpine JS

In this lesson, we build a little app that fetches dog photos from the dog.ceo API, based on a "breed" search field. We want the API call to happen again when the search value changes, and to do so we use the `$watch` property from Alpine JS, which lets us define what state property we want to watch, and what callback function to run when a change happens.

We also use the `debounce` modifier on the `x-model` property to avoid firing an API call on each keystroke.

Refetch API data when a state value changes with the `$watch` property in Alpine JS

Welcome to this beginner level series on Alpine JS! 👋🏞

Alpine JS is a rugged, minimal framework for composing JavaScript behaviour in your markup. It brings declarative, reactive, data-driven nature of libraries like React or Vue to your HTML templates.

This is the series intro video. Let's get started!

Series Intro - Beginner Level Alpine JS

If you make a mistake when naming your database column, and have data that you want to keep unchanged. You can use the change method with the rename_column definition in your migrations files to update a single column name in your database.

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