 Courses from Elijah Manor

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

In this lesson we convert a full-screen layout to use the `react-blessed-contrib` Grid component. Instead of using percents to position our components, we can build our layout by placing our components inside a 12 by 12 grid.

Use the react-blessed-contrib Grid Component to Make a Dashboard Layout

Bite-size video tutorials for badass web developers.

egghead

In this lesson we create a full-screen percentage based layout using `react-blessed`. We start with a Today component, extract out a common Box component, then start adding placeholder components in the terminal using positions via percents.

Create a Full-Screen Dashboard in `react-blessed` using a Percentage Based Layout

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

When needing to format a number I've tended to lean towards [Number.prototype.toFixed()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed), reach for a 3rd party library, or write custom functions. However, with modern browsers, there's a lot of really interesting native capabilities you could start using with [Number.prototype.toLocaleString()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toLocaleString)or [Intl.NumberFormat](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat).

Natively Format JavaScript Numbers

The ability to natively format dates and times using the browser is impressive. You may find yourself not needed to grab libraries such as moment.js or date-fns when doing simple formatting and better yet, the browser support is surprisingly good!

Natively Format JavaScript Dates and Times

In this lesson we focus on ways to position text inside a `react-blessed` `<box>` element. Instead of using a multiline template literal, we use `<text>` elements and provide props of `top`, `right`, and `left` to align content within its container.

Position and Align Text inside a `react-blessed` <box> Element

The text in our terminal node app is a bit boring at the moment. This lessons introduces the [`chalk`](https://npm.im/chalk) and [`gradient-string`](https://npm.im/gradient-string) modules to bring a bit of color to the application. You could manually use [ANSI escape codes](https://en.wikipedia.org/wiki/ANSI_escape_code) to style text, but using a helper library like `chalk` or `gradient-string` makes the task much simpler. 

Change text color with `chalk` and `gradient-string` inside `react-blessed`

While extracting a custom useRequest hook from our Terminal React Dashboard we encounter a run-away useEffect bug. As a result we introduce the [stop-runaway-react-effects](https://github.com/kentcdodds/stop-runaway-react-effects) tool to help detect the bug and then fix the it with useMemo and then the [use-deep-compare-effect](https://github.com/kentcdodds/use-deep-compare-effect) hook.

Extract a custom useRequest hook to simplify fetching data in a react-blessed Application

In this lesson we will be adding weather information to our `react-blessed` Terminal Dashboard using the `weather-js` node module. This module uses an error-first callback style API, but we'll convert it to a promise with `util.promisify` so that we can use it via `async`/`await`.

Fetch the current weather with `weather-js` and display in `react-blessed`

Currently most of the code for our React Terminal Dashboard is all in one big file. This can become a problem as we continue to build the dashboard as it can hard to managed. So, we'll move out each section of our dashboard (which is just one at the moment) into their own React component. Along the way, we'll refactor a useEffect/setTimeout to leverage the useInterval custom hook.

Extract a `react-blessed` Component and Add the `useInterval` Hook

This code at this point in the React Terminal Dashboard series is minimal, but as code starts to accumulate it'll be helpful to statically analyze the validity of our code going forward with ESLint and several plugins that are specific to React.

Add ESLint Rules to a `react-blessed` Application

In order to make text a bit more interesting in a `react-blessed` terminal app, we'll use the `figlet` node module to spice up our text with a bit of fancy ASCII Art. We'll define an array of various fonts and iterate through them every second as we experiment with this feature.

Change text font with `figlet` inside a `react-blessed` Application

In this collection of lessons we will create a developer dashboard in the terminal using react-blessed and react-blessed-contrib. We will discuss various ways to layout the dashboard, show how to change fonts, style with colors, and position text within each widget. Then we will shift focus on creating some widgets to display developer content such as an interactive time log, a pomodoro timer, displaying recent commits, currently running docker containers, and more. Once you know the basics you can create a widget of your own to add to the dashboard.

Build a Terminal Dashboard with React

In this lesson we will start to create a terminal React application with [`react-blessed`](https://github.com/Yomguithereal/react-blessed), which is a custom renderer for React. If you already know how to use React with the DOM, then you should be able to leverage a lot of what you already know to build an app for the terminal.

Bootstrap a `react-blessed` Terminal Application

In this lesson we are going to build a React Teleprompter web application using the [`Web Speech API`](https://developer.mozilla.org/en-US/docs/Web/API/Web_Speech_API). In particular, we'll use the [`SpeechRecognition`](https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognition) interface to recognize the user's voice, match the words to a predefined script, and automatically scroll to the next unspoken position. 

Create a React Teleprompter using SpeechRecognition, string-similarity, and scrollIntoView

In this lesson we focus on toggling animations on and off using the prefers-reduced-motion media query. The sample web app has 3 types of animations (CSS, SVG SMIL, and JavaScript) and we will toggle these animations using different techniques such as @media, matchMedia, and a custom hook.

Use the `prefers-reduced-motion` media query to toggle CSS and JavaScript animations

Cascading Style Sheets bring order and beauty to our applications.

Firefox DevTools has an awesome feature that helps you determine Inactive CSS, to know why it's inactive, it gives you hints on how to fix it, and even links to documentation for additional help.

Understand why CSS has no effect with the Inactive CSS rules indicator in Firefox DevTools

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

node

When you or your team work on various npm or yarn projects it gets hard to remember which one is which. This lesson shows you how to create a custom `npm` zsh function alias to remind yourself to use yarn commands when there is a `yarn.lock` file in the directory.

Make a zsh function alias to enforce using yarn commands when in a yarn project

In this course we start by getting your environment setup for hooks and then we’ll introduce the idea of adding state to a function component and unpacking several ways to interact with that state.

There are a few rules that you need to follow when you start using hooks, but thankfully there's a custom ESLint plugin that’ll help enforce these rules. I’ll show how to setup the hooks plugin and talk about some of the rules that should be followed.

Things get more interesting and involved once we introduce side-effects to our function component with the useEffect hook. We’ll uncover numerous things to consider while using this particular hook.

One of the cool features of hooks is that it’s easy to abstract out code for reuse with custom hooks. The React community has already created lots of custom hooks that you can start playing with today.

Once I've introduced the main concepts of useState and useEffect, I'll start to unpack other hooks such as useRef, useReducer, useContext, useMemo, and useCallback.

Introduction to Reusable State and Effects with React Hooks

Refs have been a handy way to reference DOM elements in Class Components, but did you know you can use refs for other things as well? In this lesson, we’ll examine how to leverage the useRef hook inside a Function Component. We’ll first use this ref to attach to a React element, which you may already be familiar with, but then we’ll examine how to use a ref to simulate a Class instance variable.

Use the React useRef Hook to Reference a DOM Element or Simulate an Instance Variable

As an alternate to useState, you could also use the useReducer hook that provides state and a dispatch method for triggering actions. In this lesson, we’ll centralize logic that is spread across a web application and centralize it using the useReducer hook.


Use the useReducer Hook and Dispatch Actions to Update State 

React changed their Context API in version 16.3 to include Provider and Consumer components. Inside of a Function Component you can leverage the useContext hook to wire-up a consumer instead of using the Render Props Consumer component.


Use the useContext Hook to Wire-up the React Context API 

When comparing two visually similar websites, it can often be challenging to precisely identify the subtle differences between them. To facilitate a rapid analysis of these discrepancies, a practical technique involves leveraging Chrome's integrated developer tools to capture full-page screenshots of each site. Subsequently, these screenshots can be uploaded to a platform like AI Studio. There, the AI can analyze the images and generate a report detailing the variations. This entire process, leveraging a few quick shortcuts, can be completed in under a minute, delivering a comprehensive breakdown of the differences for efficient comparison and analysis.

Quickly Compare Two Sites Using AI Studio with Chrome Full Page Screenshots

It's fairly trivial to create a React project, but there's always a big hurdle between creating it locally and making it shareable so that someone else can run it. This lesson walks you through the process of automating creating a React project locally, creating the repository where it's going to be hosted, and creating shareable links where it can be run so that you can quickly and easily create single one-off demos and shoot them over to your friends and coworkers for sharing your code ideas in a working environment.


```bash
share-react-project() {
  if [[ -z "$1" ]]; then
    echo "Usage: share-react-project <project_name>"
    return 1
  fi

  local project_name="$1"
  local github_username=$(gh api /user --jq '.login')

  echo "Creating Vite project: $project_name"
  pnpm create vite "$project_name" --template react

  cd "$project_name"

  echo "Initializing Git repository"
  git init

  echo "Adding all files to Git"
  git add .

  echo "Creating initial commit"
  git commit -m "Initial commit"

  local codesandbox_link="https://codesandbox.io/p/github/${github_username}/${project_name}"

  echo "Adding CodeSandbox link to README.md"
  echo "" >> README.md
  echo "## CodeSandbox" >> README.md
  echo "[![Open in CodeSandbox](https://assets.codesandbox.io/github/button-edit-blue.svg)](${codesandbox_link})" >> README.md

  echo "Adding README.md to Git"
  git add README.md

  echo "Committing README.md changes"
  git commit -m "Add CodeSandbox link"

  echo "Creating GitHub repository: $github_username/$project_name"
  gh repo create "$github_username/$project_name" --public

  echo "Pushing to remote 'origin'"
  git push -u origin main

  echo "Project '$project_name' created successfully!"
  echo "GitHub repository: https://github.com/$github_username/$project_name"
  echo "CodeSandbox link: $codesandbox_link"
}
```

Automate Creating a Local React Project, GitHub Repository, and Live Hosted Demo in a Single Command

[Verdaccio](https://verdaccio.org/) is a fully featured NPM registry that you can run locally on your machine. It’s a great tool for testing your release process, running end-to-end tests, and simulating real-world scenarios like deploying packages, installing them, and verifying functionality as an end user would.

Nx includes a [generator](https://nx.dev/features/generate-code) that simplifies setting up Verdaccio. To configure it, run:

```shell
npx nx g @nx/js:setup-verdaccio   
```

This command installs the necessary NPM packages and creates a `project.json` file with a `local-registry` target. To start the local registry, open a new terminal window and run:

```shell
npx nx local-registry
```

This will:
- Launch the Verdaccio registry.
- Configure NPM to point to the local Verdaccio server at `http://localhost:4873`.

> **Note:** A `project.json` file provides an advanced way to define scripts, offering more flexibility than a traditional `package.json` for managing complex targets.

Setup local Verdaccio server to release NPM packages

Learn how to spin up a local NPM registry powered by Verdaccio to test deploy your NPM packages.

In TypeScript, developers often begin by defining the structure of their data using type definitions or interfaces, which is a powerful way to ensure type safety. However, as applications grow and become more complex, simply defining the shape of an object might not be enough to guarantee its consistent creation and behavior throughout the codebase. This often leads to situations where objects that are intended to be of a certain "type" might be missing crucial properties or have incorrect data, which can be difficult to track down and debug.

This lesson tackles the question of when and why to move beyond basic type definitions and embrace classes in TypeScript. It demonstrates how classes provide a more robust mechanism for defining object structure, enforcing type constraints, and ensuring consistent object creation. By establishing a clear blueprint for objects, classes not only improve compile-time type safety but also offer runtime benefits and better code organization, ultimately helping developers avoid common pitfalls associated with loosely structured objects in larger TypeScript projects.

Stop Avoiding Classes in TypeScript

Karabiner isn't only for your keyboard. It can also hijack your mouse buttons and enable them to be similar to layers on your keyboard, where holding down a mouse button can allow you to tap keys on your keyboard to trigger commands and macros that can completely revolutionize your workflows. For example, you can hold down the right mouse button and tap on R to go to references in VS Code. Or hold down the right mouse button and tap the left mouse button to chop up videos and Screenflow.

This completely unlocks a whole new world of possibilities and use cases for your mouse as you can hover your mouse over anywhere on the page. And just tapping keys on your keyboard allows you to trigger mouse actions, to trigger keyboard actions, or to trigger macros and applications and terminal commands. and anything that your imagination can come up with. 

Karabiner: Rethinking Right-Click as a Macro Command Center

Make an HTML table more readable on mobile devices by using the ::before pseudo-element. We add labels to each cell, so they appear like cards when the table is viewed on smaller screens. The ::before content is set using a data-label attribute for each cell to enhance mobile viewability without horizontal scrolling.



Create a mobile friendly table with the before pseudo-element

Learn to use CSS ::before pseudo-element for mobile-friendly HTML tables. Add labels to cells for enhanced readability on mobile, avoiding horizontal scroll.

Any app of a decent size has event flows and messages being passed around. At a certain point it becomes complicated to explain it through prose and you want to turn towards diagrams. Now setting aside the time to create diagrams that accurately describe what's happening in your codebase can be quite time consuming. Luckily, with today's AI tools, we can now just do basic walkthroughs with rough recordings over codebase dictating what's going on along the way and then upload that to tools like AI Studio and then ask it to generate diagrams in a text-based format such as Mermaid that will then generate the flowcharts and diagrams for us. So this video walks us through this process of recording a rough video, uploading it to AI Studio and then asking AI Studio to generate the proper Mermaid diagram syntax.

Generate Mermaid Flow Chart Diagrams with Gemini 2.0 from Rough Screen Recordings

I'm a diehard Karabiner user and anytime I start doing something repetitively I always move it into my Karabiner configuration. Sometimes I'll fall into scenarios where I want to trigger a command, but I also want to know if that command succeeded or failed. Since Karabiner can trigger any command, setting up the command is fairly straightforward, but knowing whether it succeeded or failed became much more difficult. Luckily for me there is a package called terminal-notifier that you can install from homebrew and you can pipe the output of your command to terminal-notifier. And have a seamless way of triggering your keyboard shortcut which runs a command and you can be notified of the results.

Use Karabiner to Trigger a Terminal Command and Get Notified of the Results

There are a lot of scenarios when inspecting a site in Chrome where you don't want any click events to fire and you don't want any scripts to run. Or maybe something is animating in and out of the page and you want to capture it at a certain moment. This is a great use case for pausing script execution, which is kind of using the debugger manually by going into the Chrome DevTools and the Sources tab and clicking the pause button to essentially pause the entire page. This will give you a chance to inspect any of the elements and styles you want to inspect. And you don't have to worry about fire and click events or anything that might interrupt your investigation into the elements and styles that you want to find.

Pause Script Execution in Chrome to Easily Inspect Elements

Gemini 2.0 has a context window of a million tokens, and this means that you can upload hundreds of files and allow it to inspect and analyze massive refactors across entire code bases. 

This lesson demonstrates concatenating an entire code base into a single file and then uploading it to AI Studio. Once within AI Studio, we ask it to find the types of tasks that it can evaluate for us. Then we select one of the tasks and ask it to generate instructions for that task. Once those instructions are complete, we then turn them over to Windsurf's Cascade agent, and we allow Windsurf's Cascade to do all of the work for us as we sit back, relax, and let the AI do our jobs.

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