Learn Docker, Tweenlite and Xstate

Jotai's state management is primitive and flexible. This gives you room to build, compose, and share state throughout your application exactly how you need it.

This flexibility can become hard to manage when you have complex requirements that span across a number of states your application can be in.

Jotai lets you leverage other state management solutions through integrations so that you can solve the problem you're facing exactly how you need to.

One of those integrations is XState. XState gives you a safe abstraction to enumerate and handle the complex states your application can be in.

With Jotai + XState, you get the flexibility and ease of use of Jotai with the power of XState.

XState is a sophisticated library to provide a better and safer abstraction for state management. 

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

Complex State Management in React with Jotai and XState

Statecharts are a formalism for modeling stateful, reactive systems. This is useful for declaratively describing the behavior of your application, from the individual components to the overall application logic.

xstate

Sometimes adding initial values through the jotai Provider is not what you want. Provider will create a whole new store with atom values

One way to initialize a state machine inside Jotai is to turn our initial `lightAtom` into a function `createLightAtom`. This function will take an `initial` property that we can pass to `createLightMachine` when we declare the function. We will then useEffect to initialize our lightMachine.

There is a small limitation with this pattern, the machine is initialized with it's default value and then over ridden with the value we pass in the effect. The initial render will use that default value while the second render will have the value we passed in.


Initialize a Xstate Machine with Jotai Atom in Atom Pattern

We currently have a machine that displays a circle of green. When you click it, it will cycle through green, yellow, and Red.

What if you wanted to pass XState initial values from Jotai, you'll need to use the `initialValues` prop on Jotai Provider and pass a list of pair (atom and value) to it.

To do this we'll refactor the creation of the lightMachine to be a function that accepts an atom as an initial value.

One note to be aware of is that this initial value will only be set when the XState machines instantiate.


Provide XState with Initial Values through Jotai Provider

Sometimes you need to display values in specific ways throughout your application based on the state that you are managing. The way to do this is to derive your state so you don't have to track multiple stateful items.

In Jotai, this is accomplished by creating an atom, getting the value from another atom that you are managing (in this case from Xstate), and using that value how you need it in your derived atom. This atom will be re-evaluated every time the managed state changes.

This pattern is great to use if you have complex state managed in something like Xstate but need a derived state value that is not strongly tied to that managed state. The pattern works the same for async and synchronous function calls as well as pulling in multiple atoms and libraries to use in your derived state.


Derive Jotai Atom State from Complex State Managed in Xstate 

Jotai has a primitive and flexible API, because of this it's up to you on how you manage your state within an atom. 

Sometimes your state is complex enough to warrant a sophisticated library for safer abstraction. This is where you can install xstate to your application and Jotai will work seamlessly with the state machines that you define using `atomWithMachine`.

This allows you to consume the machine like any other atom in your components with `useAtom`. 

As an added bonus, I'll show you how to use xstate's visualizer to develop and interact with your state machine in dev tools. 


Handle Complex State in Jotai with XState using atomWithMachine

Docker containers wrap a piece of software in a complete filesystem that contains everything needed to run: code, runtime, system tools, system libraries – anything that can be installed on a server. This guarantees that the software will always run the same, regardless of its environment.

docker

The end is nigh. Your application is almost ready, and you will need to deploy it. And with the deployment, the endless tweaking to get everything running on your production servers. 

If only there were a way to test everything first. That is where containers will come in to save the day. With containers, you not only run your code in an environment similar to the production server, but you also run your code in precisely the same environment. 

In this talk, the attendees will learn about how to create container friendly applications and how to use containers to share their code with their team.

Containers for Software Developers

While "It works on my computer" might give you an excuse to close a bug ticket in the backlog, it doesn't really work when you're working on a team.

You need to ensure that your application can run regardless of what hardware your teammates are running or libraries they have installed.

Docker solves this problem by collecting everything your application needs to run into a container.

Containers aren't just for source code. They can hold configuration, scripts, and even their own filesystem. It's similar to a Virtual Machine, without having to bring a full operating system along for the ride.

Because containers run in isolation, there is some configuration involved to allow for files to be saved and containers to communicate with one another.

One of the most useful ways to get your head around Docker is to see it in action.

Follow along with Joel Lord as he works through the process of preparing an application to run in separate containers for the frontend and backend of an application that searches for gifs and re-encodes them with a caption supplied by the user.

You'll see how to configure the separate containers to communicate with one another, work with environment variables, and persist data to your local machine. Along the way, you'll pick up some tips on useful commands and bash scripting. Finally, you'll learn how to use Docker Compose to make it easy to run multiple containers simultaneously.


Containerize Full-Stack JavaScript Applications with Docker

Now that all three tiers of your application are available in containers, you'll need to push those images to container registries. Registries are the container equivalent to repositories for your code. Registries can be public or private. 

In this lesson, we'll use Docker Hub to push our images. Docker Hub repositories allow you share container images with your team, customers, or the Docker community at large.

Docker images are pushed to Docker Hub through the `[docker push](https://docs.docker.com/engine/reference/commandline/push/)` command. A single Docker Hub repository can hold many Docker images (stored as **tags**).

Images pushed to a public registry can be downloaded by using the `docker pull` command. Once they have the image downloaded, they can use Docker run to start each container just like you did in the previous steps.

Push a Docker Container Image to Docker Hub

In the last lesson [Create a Custom Image with a Dockerfile running Node.js](https://egghead.io/lessons/docker-create-a-custom-image-with-a-dockerfile-running-node-js?pl=introduction-to-docker-afaf), our backend stopped working again because it couldn’t find the database.

One of the advantages of running containers is that they run in isolation. As far as the container is concerned, nothing exists outside of it. It behaves as if it was its own operating system. This is why the backend can’t find the database on "localhost". The two containers are running on the same host but as far as the backend is concerned, there is no database. The same goes for the database. It can’t see anything outside of what is running in its container therefore it can’t see the backend application running.

When you need a way for multiple containers to talk to each other, Docker has a tool called networks to help you. We'll use a network to allow our backend to successfully connect to the database.

Allow Containers to Communicate through Docker Networks

You will learn how to create your own images that will include all the source code of your application, along with a specific version of Node.js and all the dependencies that are needed. Once you are done, you will be able to share this image with other people and this will ensure that everyone is running the same environment. It will event let people that don’t have Node.js run this server. This will also have the added benefit of cleaning up everything once you close the application.

You'll notice that we will run into the same error stating we can't connect to the database. This is expected and we'll fix this in [Allow Container to Communicate through Docker Networks](https://egghead.io/lessons/docker-allow-container-to-communicate-through-docker-networks)

Create a Custom Image with a Dockerfile running Node.js

First, we'll see how you can have different run-times installed in a docker container that isn't dependent on your system's current installs. You don't need anything but docker to run these containers! We will demonstrate this by installing the latest version of Node.js in a docker container and compare that to the version of Node.js I'm running on my machine.

Next, you'll see how to pass environment variables to containers. This is important because you will use these variables for API calls as well as configuring databases, and more!

Use Environment Variables for Docker Containers

In this lesson, you will learn how to start basic containers and how to use them in your day to day developer life. You will also learn how to start a database container that can be used with the demo application for this course.

Running Your First Container

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

First, we'll get a tour of the application and what it does then we will start configuring a fresh project. 

The application UI is simple. It asks for a keyword and will search and display a random GIF from Giphy. Once you are satisfied with the image, you will be able to add a caption to it. The server will deconstruct the GIF frames, add the caption and re-create the GIF for you. Everything is then saved to a database so that all the users can benefit from your creations.

The tech involved to do this is a Vue frontend, Node.js backend, and MySQL database. I'll walk you through cloning, installing dependencies, configuring the giphy API key that we use, and starting the application. You'll notice at the end we'll need to configure the database. We'll get an error but this is expected!

Configure and Run a Node.js API Powered by a Vue Application

Now that you have three containers ready to be used, you will learn how to create a docker-compose.yaml file. By using Docker Compose, you will be able to share a single YAML file and anyone will be able to run your application.

Docker-compose is part of the Docker tools suite and is an application that will take a YAML file to start all of your containers with one single command. 

Using Compose is basically a three-step process:

1. Define your app’s environment with a `Dockerfile` so it can be reproduced anywhere.
2. Define the services that make up your app in `docker-compose.yml` so they can be run together in an isolated environment.
3. Run `docker-compose up` and Compose starts and runs your applications. 

Compose works in all environments: production, staging, development, and testing.

Use Docker Compose To Share An Entire Application

Introduction for the lesson on using environment variables in a front-end container

Mini talk - Access Environment Variables in a Dockerfile to Build a Front-End Container

In this small talk, the instructor explains why you need to use a multi-step build to prepare your front-end container.

Mini talk - Containerize the Front End of an Application with a Multi-Step Docker Build

Docker containers that are running on your local machine can't communicate with each other. In this mini talk, the instructor explains why and shows a demonstration of Docker networks.

Mini talk - Allow Containers to Communicate through Docker Networks

This course will take you through the process of preparing an application that's configured for development to deployed on a Kubernetes cluster.

First, you will need to tweak your application so that it can run in containers. Then, you will see how you can use containers to complement your application and run a database without even installing the actual software. Eventually, you will create a whole environment with your containers that will enable you to start all the applications with a single command. This can be useful to share the application with your colleagues.

We'll make sure you have the correct software installed on your machine to get started.

You will need a few software installed:

- [Node.js](http://nodejs.org)
- [Docker](http://docker.com/) or [Podman](http://podman.io/)
- [git](http://git-scm.com/)

As well as an [API key from giphy](http://developers.giphy.com/)

Course Intro: Containerize Full-Stack JavaScript Applications with Docker

Running our server as a Non-Root user is very important for testing things such as quality assurance. Many things can get missed when using a privileged account such as your root user account. Here we need to set up and change the Nginx configuration to run as a Non-Root user. 

This container uses two steps. The first step uses a container to build the production version of your VueJs application. This container won’t be deployed on a server, its purpose is to create the necessary files for the second step. It's fine to leave this container running as root. 

In the next step of the build, the Nginx server is the one that will need to run as a non-root user because it is actually run on servers you want to deploy to. To do so, you will first need to change the Nginx configuration to run the build using the Nginx user with files modified for that user to access them.

Run an Nginx Image as Non-Root Within a Multi-Step Docker Build Process

Starting up our server and running the curl command `curl localhost:3000/health`, we find that we get an error. Our server is complaining about us not having a database. Since this is a fresh install, we have no data at all. SQL comes with a file called `init.sql` inside of your `db` folder that will create a database, add the necessary tables for our application, and prepopulate the table with a single entry. We just have to put it in the folder that MySQL will use to populate the database!

Integrate a MySQL Docker Container Into an Application

Running MySQL in a Docker Container is great for being able to emulate various environments. The more advanced containers will include a bunch of executables and runtimes that will allow you to do run more intricate commands. These commands can be very useful for sharing with other teams for testing purposes. It doesn't matter what runtimes they have on their end, by using the `docker` command, you'll be able to specify what runtimes to use to execute your code. 

Run MySQL in Docker Container

I've been using Cursor for a very long time and their "Agent" feature in Composer is fairly new, so I'm still getting used to it. But since Windsurf recently got onto the stage with their Cascade agent, they've slowly been gaining the mind share on the UX for coding agents. I decided to put them to the test by putting Windsurf and Cursor on the exact same screen side by side trying to accomplish the same task and to see which workflow I would prefer. I've been a diehard Cursor user for over a year now, so it's going to take a lot for me to switch to a different IDE. But I just have to say, even from this simple demo, Windsurf is looking pretty nice.

This lesson is just going to walk through creating a CLI using both tools to print out inspirational quotes and to explore how they approach the step-by-step of installing packages and running commands and setting up all the files we need to get this running.

Windsurf Cascade vs. Cursor Composer Agent Side-by-Side Comparison

This TypeScript tutorial explains how to use generics, allowing for different types to be passed as arguments. It discusses the use of shorthand syntax in generics and illustrates with examples. This method is useful for library creation, providing type safety and control to the user.

```typescript
interface PhotoMetadata<T> {
  title: string;
  takenAt: Date;
  customData: T;
}

// Function that processes a photo with custom metadata
function processPhoto<T>(photo: PhotoMetadata<T>): {
  processedTitle: string;
  daysSinceCapture: number;
  customDataSummary: T;
} {
  const today = new Date();
  const daysSinceCapture = Math.floor(
    (today.getTime() - photo.takenAt.getTime()) / (1000 * 60 * 60 * 24)
  );

  return {
    processedTitle: photo.title.toUpperCase(),
    daysSinceCapture,
    customDataSummary: photo.customData
  };
}

// Example usage with different custom data shapes
type CameraSettings = {
  iso: number;
  aperture: string;
  shutterSpeed: string;
}

type LocationData = {
  latitude: number;
  longitude: number;
  locationName: string;
}

// Using with camera settings
const photoWithCamera: PhotoMetadata<CameraSettings> = {
  title: "Sunset at beach",
  takenAt: new Date('2024-01-15'),
  customData: {
    iso: 100,
    aperture: "f/2.8",
    shutterSpeed: "1/1000"
  }
};

// Using with location data
const photoWithLocation: PhotoMetadata<LocationData> = {
  title: "Mountain vista",
  takenAt: new Date('2024-02-01'),
  customData: {
    latitude: 45.5231,
    longitude: -122.6765,
    locationName: "Mount Hood"
  }
};

const processedCameraPhoto = processPhoto(photoWithCamera);
const processedLocationPhoto = processPhoto(photoWithLocation);

processedCameraPhoto.customDataSummary.iso
processedLocationPhoto.customDataSummary.longitude

```

Basic Explanation of Typescript Generics

A very basic explanation of generic function arguments

I've been using Cursor as my primary editor for over a year now, but recently I've heard wonderful things about Windsurf AI Agent features. I decided to record myself building out something I've always wanted to make, but never made the time for.

In this lesson, I demonstrate how to leverage Windsurf's powerful agent process to create a fun word-guessing game inspired by Heads Up. Watch as I build an interactive application featuring category selection and word navigation, complete with data hosting on GitHub Gists and deployment to GitHub Pages - all in under 30 minutes (before editing the lesson down to 12 minutes)!

What makes this project particularly exciting is how Windsurf eliminates the typical friction points of development. While this game was always on my project wishlist, the overhead of setup, configuration, and deployment made it hard to justify the time investment. Windsurf's agent process handles all these pain points seamlessly, from managing URLs to orchestrating deployment.

This lesson perfectly showcases how AI agents can help developers bring their backlog of project ideas to life, transforming what would typically be time-consuming tasks into efficient, enjoyable development experiences.

Build a Word Game with Windsurf's Cascade AI Agent



Discover how to harness the power of Cursor IDE's Composer Agent feature to optimize your code. In this lesson, you'll witness an AI agent doing all the work to generate test suites, implement performance benchmarks, and create optimized function variations - all without writing a single line of code. You'll learn how to validate performance improvements through data-driven benchmarking, ensuring that optimizations are backed by concrete metrics rather than speculation. This hands-on demonstration showcases a groundbreaking approach to automated function development that combines the precision of test-driven development with the efficiency of AI-powered optimization.


Agent-Driven Development in Cursor: Testing, Benchmarking, and Optimizing Functions

This course is aimed for using `zod` effectively in projects based on TypeScript (both browser and node.js). The benefits you gain with this course is not just simply coding, but also understanding when/why/how should you perform runtime validation.

`zod` is the missing piece to TypeScript's capabilities, which can guarantee type-safety only in compile-time.

`zod` can be used whenever the compiler cannot guarantee what happens in runtime. And... it's a very frequent usecase, such as HTTP calls, websockets, etc.

In this course you get quickly up and running by:
1. using `zod` with primitives and objects
2. adapting `zod` quickly to existing projects thanks to automatic generators
3. changing the strategy frm type-first to schema-first
4. using error-throwing `parse` or non-error-throwing `safeParse` basing on your needs
5. applying `zod` to the most common usecase - validating API responses
6. handling errors the most convenient way (out of many!)

Take advantage of runtime validation with `zod`. Take advantage of the detailed lessons in this course 🔥

Effective Runtime Type Checks with Zod


Cursor can now automatically run commands in the terminal and walk step-by-step towards building out your entire project. You give it a goal, then it will suggest the commands you need to run and the files that you need to create and you can work with it to achieve what you're building. This lesson does a quick walkthough of using a Cursor Agent to build a project from scratch and guide it along the way. Cursor Agents definitely feel like a sneak peek at the future of programming!

Cursor Agents Initial Impressions - Allow an AI to Build Your Entire Project

Mock Service Worker is an API mocking library that allows you to write client-agnostic mocks and reuse them across any frameworks, tools, and environments.



Mocking WebSocket APIs with Mock Service Worker


While using anonymous functions might seem convenient, they can create difficulties when trying to identify performance bottlenecks during profiling. This lesson will demonstrate how named functions make it easier to pinpoint and address performance issues, ultimately leading to more efficient and debuggable code. Learning this practice will greatly improve your ability to locate and fix performance issues in complex projects.

Always Name Functions in JavaScript


When attempting to load the same module twice in JavaScript you'll hit a cache and code won't re-run. In scenarios where you actually do want to have state in your modules, you'll have to use a cache-busting technique by passing a query parameter to a dynamic import. This lesson walks through how to add a query parameter, how to add the appropriate types for loading dynamic modules in TypeScript, and when these techniques are valuable.

Import the Same JavaScript Module Multiple Times with Cache Busting



The include keyword in GitHub Actions empowers you to add custom variables to your matrix strategy, providing flexibility beyond standard configurations. In this video, we'll explore how include allows you to define specific combinations of variables, enhancing control over your workflow runs. You'll see how this feature enables you to tailor jobs for unique environments or scenarios not covered by the default matrix options. By leveraging include, you can efficiently manage complex build processes with greater precision. This technique helps you streamline your CI/CD pipeline, making it more adaptable to your project's evolving needs.

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