Learn Electron, Scss 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

Sass is the most mature, stable, and powerful professional grade CSS extension language in the world.

scss

Learn the essentials of enabling semantic form validation HTML and styles in preparation to use our form design system with the validation solution of your choice.

We will add an SVG to our form descriptions when the error class is applied and look at a workaround to style the SVG through a Sass function.

Create Accessible Styles for Invalid Form Fields

Let's add a key missing element to our form design system - the submit button! Learn how to reset browser styles, and use our theme system to create accessible styles across `:hover`, `:focus`, and `:disabled` states.

Create Custom CSS Styles for Form Submit Buttons

Often we can improve the user experience by grouping related fields, such as first and last name. In these cases, it's appropriate to include `<fieldset>`. We'll first learn how to semantically create the fieldset HTML. Then, we'll set up a series of scalable classes that are flexible for various layout configurations. The layout classes will also be intrinsically responsive - meaning, they will respond to their parent container _or_ the viewport without the use of media queries!

Define Semantic Fieldset HTML and Create CSS Styles For Responsive Form Layout

In the last two lessons, we set up the initial state styles for radio buttons and checkboxes. Now we'll add styles for the focus and disabled states using our existing Sass mixins. We'll do this by layering box-shadow effects of a white border and blurred primary color.

We'll also learn about an up and coming pseudo selector - `:focus-within` - that will be used to apply styles to the label of a control in a `:focus` state.

Create Custom Radio Button and Checkbox CSS Styles for Focus and Disabled States

We'll setup the layout structure for our custom radio button and checkbox styles using CSS grid. These input types will share the `.form-control` component styles. This lesson will apply the initial styles to prepare for creating custom visual control styles.

Similar to focus states for selects, we will need to add a wrapping span and nested span to our radio buttons and checkboxes to apply visual styles to these native elements.

Create A Layout Structure with CSS Grid For Radio Buttons and Checkboxes

In the previous lesson, we set up the initial state styles for form selects and multi-selects. Now we'll add styles for the focus and disabled states, inclusive of a workaround necessary due to the lack of a parent selector in CSS.

The way we will get around this for our focus styles is to add a sibling span element to apply the styles and position those styles on top of the Select element.

Create Custom Select CSS Styles for Focus and Disabled States

We'll begin to apply our theme styles for our text inputs by creating the `.form-field` component. We'll make use of the Sass feature of "mixins" to create `:focus` and `:disabled` styles that can be reused. While creating the `:focus` and `:disabled` states we'll discuss the importance of contrast and keyboard access for accessibility.

An important take-away is that you need at least a 3:1 contrast ratio between your border and background AS WELL AS a 3:1 contrast ratio between your border and focus state.

Use Sass Mixins to Style Inputs with Accessible Contrast and Keyboard Access

Using modern CSS and in particular CSS grid and `clip-path` we can define cross-browser compatible custom select CSS styles inclusive of the dropdown arrow. We'll continue ensuring all styles are re-themeable by using the Sass functions we've already created within our form design system. We will style both the default single select, and a multi-select using `multiple`.

Create Custom Form Select and Multi-select CSS Styles

Learn how to begin addressing browser inconsistencies by resetting base styles across text inputs, textareas, and selects. We'll also review a few quirks related to mobile browsers and responsive design when dealing with form fields. And we'll uncover how to normalize `<select>` which was formerly one of the trickiest fields but is vastly easier now thanks to modern CSS through the `appearance` property.

Create Reset Styles to Normalize Form Fields Cross-Browser

We'll make a starting point for our form layout styles by creating `.form-group` which will add a bit of `margin` between fields. This will be our first design system component, and we'll also include styles for the `label` contained in this class.

Create the `form-group` Component Styles

We'll define the color palette and create the basic screen styles for our project in addition to Sass helpers for our form design system. 

We will set up Sass variables for the initial them and learn how to use the !default flag to allow our system to be easily overridden from project to project, making our form styles ultra transferable and reusable. You'll also learn how to leverage Sass color functions for ease of theming. We'll map the Sass variables to CSS variables so that as we build up our system we can use CSS variables for the most flexibility in our theming.

Initialize the Form Design System Setup with Sass and CSS Variables

View a preview of the form fields we'll be creating in this course, inclusive of custom CSS styles for text inputs, textareas, selects, multiselects, radio buttons, and checkboxes. Then get an overview of the base project and key parts of the Eleventy build process in regards to compiling with Dart Sass and use of Nunjucks for project template scaffolding. 

Prior experience with Eleventy or Nunjucks is not required, but you may also enjoy learning how to [create an Eleventy site from scratch](https://egghead.io/playlists/build-an-eleventy-11ty-site-from-scratch-bfd3?af=2s65ms) in less than 20 mins in my other egghead collection.

Course Introduction: Accessible Cross-Browser Form Field CSS Styles

Joel and David chat about the big ideas and the essential questions of State Management and State Machines. Additionally, David also gives a walkthrough of XState, XState Visualizer, and the upcoming dev tools for XState.

## Key Terms

**XState -** is a library for creating, interpreting, and executing finite state machines and statecharts, as well as managing invocations of those machines as actors.

**State Machines** - a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of states at any given time.

**Combinatorial Explosion -**  is the rapid growth of the complexity of a problem.

## Resources

- [davidkpiano/xstate](https://github.com/davidkpiano/xstate)

- [David K. 🎹](https://twitter.com/DavidKPiano)

- [davidkpiano - Overview](https://github.com/davidkpiano)

- [Stately Newsletter](https://www.stately.dev)

## Visuals Explanation

![](https://res.cloudinary.com/dg3gyk0gu/image/upload/v1618253832/transcript-images/state-management-2021-descriptions/state-machine-states-events-transitions-actions.jpg)

Source: [https://www.stately.dev](https://www.stately.dev/)

**These notes include:** highlights, expansion of key terms, code blocks, and links to additional resources. **They follow the same structure as the recording.**

## What are the big ideas of State Management?

- It all comes down to applying big ideas from the past, for example, State Machines.
- One of the biggest problems related to State Machines is performance.
- The problems with States are not new.

## Why is this hard to understand these problems?

- **There's a mathematical explication to this.** Once you have more than one piece of State in different places, you faced Combinatorial Explosion.
- **Combinatorial Explosion**

    A combinatorial explosion is the rapid growth of the complexity of a problem due to how the combinatorics of the problem is affected by the input, constraints, and bounds of the problem.

    Combinatorics is an area of mathematics primarily concerned with counting, both as a means and an end in obtaining results.

- An example of this is having ten main ingredients and having the output be 100 different dishes.
- **The most neglected variable is time when it comes to managing State.** We can only think about this in abstract ways.
- "We (developer) do most of the State management in our heads."
    - There's no concrete way to communicate our understanding of States. This is one of the reasons why we have State Machines.

## What are the Essential Questions when people work with State Management?

- First, identify all the pieces of State that you're dealing with.
    - How is this information organized?
    - How can this data change over time?
    - How can you model this data?

## What's a Finite State Machines?

- "XState is like Redux with Rules"
- A finite state machine is a mathematical model of computation that describes the behavior of a system that can be in only one state at any given time.
- Finite State, you can only be in one State at a time.
    - It's more of a mode, "I'm awake & I'm asleep."
- It also describes how one can move from one State to another.

## What's the difference between a State Machine and Statecharts?

- Finite State Machines can represent everything.
- Statecharts are a formalism for modeling stateful, reactive systems.
- David Harel presented this formalism as an extension to state machines in his 1987 paper [Statecharts: A Visual Formalism for Complex Systems](http://www.inf.ed.ac.uk/teaching/courses/seoc/2005_2006/resources/statecharts.pdf).
    - A way to organize your states. "Sub-States."
- **More resources:**
    - **[Finite-state machine](https://en.wikipedia.org/wiki/Finite-state_machine)** article on Wikipedia
    - **[Understanding State Machines](https://www.freecodecamp.org/news/state-machines-basics-of-computer-science-d42855debc66/)** by Mark Shead
    - **[▶️ A-Level Comp Sci: Finite State Machin](https://www.youtube.com/watch?v=4rNYAvsSkwk)**

## How are State Machine addressing the big ideas of State management?

- Event-Action approach doesn't always make sense. A State Machine has a specific way of transitioning.
    - A state transition defines what the next state is, given the current state and event. State transitions are defined on state nodes.
- **Communication** with humans and machines.
- **More resources:**
    - **[Statecharts: A Visual Formalism for Complex Systems](http://www.inf.ed.ac.uk/teaching/courses/seoc/2005_2006/resources/statecharts.pdf)** by David Harel
    - **[The World of Statecharts](https://statecharts.github.io/)** by Erik Mogensen
    - [Constructing the User Interface with Statecharts](https://www.amazon.com/Constructing-User-Interface-Statecharts-Horrocks/dp/0201342782) by Ian Horrocks
- **Combinatorial Explosion**
    - State Machines is not something new; it has been implemented across different industries.

## The Overlap of music and State Machines and Statecharts

- When you look at music, there are infinite ways to express a melody; inherently, there are rules.
- **Music makes you a better visual thinker.**
    - This is an example when it comes to modeling State solutions.
- Music is centuries old; its theory is old. Computer science is the music theory of programming.
    - Music theory answers why "this" works, much like when you start using a library, and you realized that it's an elegant solution to a specific problem.

## Building a Statecharts for JavaScript

- The inspiration came from David's first job working with repetitive workflows. Wanting to solve this problem led to researching State Machines.
- Early days it was called "Estado," the Spanish word for State.

## Demo of XState

[Code sandbox demo](https://codesandbox.io/s/exciting-tereshkova-cjpdf?from-embed)

- Normal React Development:

```html
    <div className="App">
      <h1>{toggled ? "Toggled" : "Nope"}</h1>
      <h2>
        {state.value} ({state.context.count})
      </h2>
      <button
        onClick={() => {
          send("TOGGLE");
        }}
      >
        Toggle
      </button>
    </div>
...
```

- The problem is the all the business logic is inside the event handle.
- If you have more business requirements, you'll need to add 'defense logic' to handle more use cases.

## Adding XState

```js
import { createMachine, assign } from "xstate";
import { useMachine } from "@xstate/react";

const toggleMachine = createMachine({
  initial: "untoggled",
  context: {
    count: 0
  },
  states: {
    untoggled: {
      on: { TOGGLE: "toggled" }
    },
    toggled: {
      entry: assign({
        count: context => context.count + 1
      }),
      on: {
        TOGGLE: "untoggled"
      },
      after: {
        1000: "untoggled"
      }
    }
  }
});
```

- `useMachine(machine, options?)` - a React hook that interprets the given machine and starts a service that runs for the component's lifetime.

```js
const [state, send] = useMachine(toggleMachine, { devTools: true });
console.log(state);
const [toggled, setToggled] = useState(false);
```

- We are creating an event-driven approach to handling toggles.
- All the logic is handle inside `toggleMachine`
- With State Machines everything is an event (time is an event).
- Existing machines can be configured by passing the machine options as the 2nd argument of `useMachine(machine, options).`

```jsx
context: {
    count: 0
  },
```

- We can add a side-effects `count: context => context.count + 1` without affecting our main State.

## XState Visualizer

![](https://res.cloudinary.com/dg3gyk0gu/image/upload/v1618256533/transcript-images/state-management-2021-descriptions/xstate-visualizer.png)

## What's the workflow for design States?

- Pen and paper work pretty well. Modeling the behavior of a user is complicated.

![](https://res.cloudinary.com/dg3gyk0gu/image/upload/v1618256586/transcript-images/state-management-2021-descriptions/workflow-for-design-states.png)

- **Dev Tools for XState (coming soon)**
    - CodeSandbox also works pretty well for prototyping state.

## When is XState not appropriate?

- You don't need a library to implement State Machines. You can use patterns in each language.
- XState becomes more valuable when representing Statecharts.
- XState version 5 will be smaller. It will be explicit, small, and fast.
- [See Twitter](https://twitter.com/DavidKPiano/status/1226182960111591426?s=20)

XState for State Management in React Apps with David Khourshid

Grid offers us the easiest method to responsively center content. We'll use the grid property `place-content` to center the contents of `figure` to showcase our fictional product in use. Additionally, we'll learn about `object-fit` which is a modern technique that allows inline images to scale responsively within defined dimensions without distortion.

Responsively Center an Image and Caption with CSS Grid

Apply grid layout and see when it's necessary to break out a media query to overcome grid's lack of wrapping behavior. We'll also learn about a property that grid and flexbox share: `align-items`.

Use CSS Grid to Create Layout Columns

It's tempting to pick up a framework which has preselected flexbox or grid as the layout tool of choice, but it's important to learn when and why to use each method. This leads to slimmer stylesheets which results in better site performance, and less likelihood for "hacks" to make one method do what the other does inherently better. 

Throughout this collection, we will be progressively styling a responsive landing page template while building your knowledge on when to select grid or flexbox for any layout scenario. Spoiler alert: sometimes the best solution is using both!

The specification describes a CSS box model optimized for user interface design. In the flex layout model, the children of a flex container can be laid out in any direction, and can “flex” their sizes, either growing to fill unused space or shrinking to avoid overflowing the parent.

flexbox

Create a Landing Page with CSS Grid and Flexbox

Windsurf and Cursor are both able to take an image and then use an agent to build out what it sees in that image. This lesson is going to compare Windsurf and Cursor by uploading the same image to both and giving them the same prompt. Comparing not only the results, but also the steps that they take to get there. We'll also try uploading additional images throughout the process to see what they do as far as revising along the way and improving the site as they go along. 

Windsurf Cascade vs. Cursor Composer Agent: Build a Site from an Image

In this lesson, you'll discover how to style View Transitions using CSS pseudo-selectors to create custom animation effects. We'll transform the default cross-fade into a smooth slide transition by targeting the ::view-transition-old and ::view-transition-new pseudo-elements. You'll learn how these powerful selectors give you precise control over your transition animations, allowing you to create more engaging and personalized user experiences with just a few lines of CSS.

Customize View Transitions with CSS Using view-transition-old and view-transition-new

In this lesson, you'll learn how to implement smooth state transitions in your web applications using the browser's built-in View Transitions API. We'll create a simple example that demonstrates how to animate between different text states with just a few lines of code - no external libraries required. This powerful native API makes it easy to add professional-looking transitions to your user interface, enhancing the user experience with minimal effort.

Create Smooth UI Transitions with the Native View Transitions API

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.



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