Learn A11y, Ampt and Aria

WAI-ARIA, the Accessible Rich Internet Applications Suite, defines a way to make Web content and Web applications more accessible to people with disabilities. It especially helps with dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies. 

aria

We'll go over the work it takes to use ARIA to show why Semantic HTML is almost always the safer bet. 

Create a Semantic Checkbox vs an ARIA Checkbox

Debug Computed Accessibility Properties with Chrome Dev Tools

In this lesson, we use the element inspector in Chrome to test and improve our contrast to meet WCAG AA Contrast Ratio Standards.

Resources:
- [WebAIM - Contrast and Color Accessibility](https://webaim.org/articles/contrast/)

Debugging Accessible Contrast with Chrome Dev Tools

“a11y” stands for “accessibility.” It is a numeronym, with 11 representing the count of letters between the letter a and the letter y.

Accessibility is broken down into 4 categories of disability: visual, cognitive, auditory, motor. 

Regardless of the category of disability, accessibilities aim in web development is to make applications and websites usable for everyone.

a11y

In this course, we'll be focusing on building an accessible component by using a built-in browser API with React to implement best practices in accessibility custom features. 

Everyone is responsible for accessibility, and we need to start creating features and websites with that in mind. The goal of this course is for you to exploit your understanding of HTML and aria, and be able to look at any common features and identify the different accessibility patterns. 

With this course you won't only learn about accessibility, but also will learn about `HTMLMediaElement` API, and state management in React. 


 





Introduction to Creating a Custom Accessible Audio Player with React

React's `forwardRef` function allows a component to receive a ref that has been created outside of it. This can be useful in cases where you want to have a specific part of your component, such as a section of a long transcript or a specific part of an audio recording, referenced from outside the component.

One example of when this might be useful is if you have a "listicle" type of audio, such as "5 things your tech resume needs", and you want to allow users to jump to specific parts of the audio. By converting the component to a forwarded ref component, you can create a ref in the parent component (in this case, the "App" component) and pass it into the audio component. This allows you to create a few buttons in the parent component that can control the audio ref and jump to specific audio sections.

To convert a component to a forwarded ref component, you can use React's `forwardRef` function to wrap the component, and then remove the audio ref and replace all instances with the new ref.

By doing this, you can now control the audio component, like play, pause and jump to a specific time, by interacting with the `audioRef` ref object created in the parent component and passed into the audio component.

**Think about:** What ways to control the audio outside the component could help with accessibility?

Using a forwardRef to Create External Controls

We are creating an accessible popup menu for a web application. It covers various concepts, including handling keyboard events, creating a new dropdown component for reuse, using arrow keys to navigate through buttons, using the Tab key to close the menu and go to the next item in the tab order, using the Escape key to close the menu and focus on the button that closes it, using the `aria-expanded` attribute to communicate whether the menu is open or closed, and the difference between the tab index values of 0 and -1. 

**Think about:**
- Why tabindex -1?
- Why would you use arrows versus tab key to navigate through the dropdown?

Create a Dropdown Menu for Rates

In this lesson, we are using HTML, accessibility concepts, and ARIA attributes to improve the time scrubber feature of an audio player. 

The goal is to make it accessible to users of screen readers so that the time scrubber announces the actual time (e.g. 12 minutes and 15 seconds) rather than just the value (e.g. 735). 

We are also creating a new folder called "helpers" in the "src" folder and a new file called "format time.js" within it to hold a function called "format human read time" that takes time as a parameter and returns the human-readable equivalent of that time. Additionally, the author debugs the code and uses console.log to check the variable.

**Think about:** Why does a human-readable name help?

Create a Human Readable Time Formatter

I suggest using the previously learned approach but keep in mind that it may lead to an overly complex markup. We also use the `aria-label` attribute, which can be used to override the text within a label element.

**Think about:** Why would you use an `aria-label` instead of creating a visually hidden span?

Using Aria-Label as a Solution for Overly Complex Markup

In this lesson, we are creating the audio player interface more visually appealing using icons from the React Icons library and Font Awesome, in this process, we are also ensuring that the interface remains accessible to screen readers by providing text descriptions for the icons, first by using the `title` prop on each icon, and then by implementing a `visually hidden` technique that hides the text descriptions from sighted users but makes them available to screen readers. This involves copying and pasting some CSS code to create a visually-hidden class, adding an `aria-hidden` attribute to each icon, wrapping each icon in a React fragment, and then adding a `span` element above each icon with the corresponding text description and the `visually-hidden` class.

**Think about:**  
- Why use `aria-hidden` or visually hide spans? 
- What value does this add to screen reader users?

Design Accessible Buttons Using Icons

We create an input range with a label, where the range is between 0 and 1 with a step of 0 - 1. The input's value should be determined by a ternary statement that checks if the volume is muted and sets it to 0 or to the current volume if not muted. 

An `onVolumeScrubberChange` function is also added that sets the volume to the event target value when the input value changes and updates the volume in the state and an audio reference. The `onVolumeChange` function does not need to be used and the logic needs to be adjusted to ensure that the volume can be updated and that it mutes when the volume reaches 0.

**Think about:** Why do we have to add `audioRef.current.volume === 0` in addition to `audioRef.current.muted`?

Implementing a Volume Range with an onChange Event

We are creating a toggle button for muting and unmuting an audio element using React hooks `useState` and `useRef`. It destructures `isMuted` from the `useState` hook and sets the initial state to false. 

The button's inner text is dependent on the state of `isMuted`, and a `toggleMute` function is created which sets `isMuted` to the opposite of its current state and also sets the `audioRef.current.muted` property to the opposite of `isMuted`. 

A `onVolumeChange` function is added to the audio element that sets the `isMuted` state based on the value of `audioRef.current.muted`. This allows the `isMuted` state to change even when the mute button on the audio element itself is pressed.

**Think about:** 
- Why do we have to add `onVolumeChange` for instead of `onMuted`? 
- How can we use `onVolumeChange` to check for things being muted?

Creating a Toggle Button for Muting and Unmuting an Audio Element in React

We are creating a playback rate button in a React application. An array of rates is created, and each element of the array is mapped to a button. Each button is given an onClick handler that calls an anonymous function called `changeRate`. 

`changeRate` sets the playback rate of an audio element to the rate passed as an argument. When the button is pressed in the browser, it shows the new playback rate.

**Think about:** We have all these states for volume, media time etc, why don't we have one for rate?

Creating a Playback Rate Button

We will create two buttons labeled "rewind 15 seconds" and "fast forward 15 seconds." Then, we created two functions, `onRewind` and `onFastForward`, to adjust the current time of a media by 15 seconds. The `onRewind` function will use `Math.max` to ensure that the time does not go into negative, and the `onFastForward` function will use `Math.min` to set a max limit. These functions will be added to the click events of the corresponding buttons. Finally, it sets the new time for the media state and the audio reference.

**Think about:** Why do you need the second parameter for `math.max` and `math.min`?

Add Fast-Forward and Rewind 15 Second Buttons

In this lesson, we will create event listeners for the play and pause events on an audio player element and use these listeners to update the value of a variable called `isPlaying` that tracks the current state of the player (e.g., whether it is currently playing or paused). The event listeners, named `onPlay` and `onPause`, will be triggered when the user presses the play or pause button on the audio player element itself, not on a custom play button that may have been created.

Add Play and Pause Events to the Audio Player

We are creating an input of type range with an associated label, this input is to represent the current playback position in the audio, and the user will be able to change the playback position using the input.

The input value is set to be the media time state, it is added a minimum value of 0 and a maximum value as the duration. The demonstration shows how the media time state updates accordingly when the user changes the time using the input range.

A function called `onScrubberChange` is added, which takes in an event as an argument and `console.logs` the value of that event. The `onChange` event is added to the input, ensuring it works as expected. A variable sets the media time state and the current time on the audio ref.

**Think about:** Why do we use the `event.target.value` to set the new `mediaTime` (reminder that the value of the range is bound to `mediaTime`....maybe take a look at that with the formatter)

Create the Audio Scrubber to Control Playback Position

In this lesson, we are creating a new state called `mediaTime` with an initial value of 0, updating sample text in the markup to display the value of `mediaTime`, and adding an event listener to the audio element for the `timeUpdate` event.

In the `timeUpdate` event listener callback function, the `mediaTime` state is set to the audio element's current time, which can be accessed using the `audioRef.current.currentTime`. A function is added to the `onTimeUpdate` event of the audio element, to be able to track the current time. And a time formatter is added to format the time for displaying elapsed time and total time.

**Think about:** How often does onTimeUpdate update? (every second, not every millisecond) 

Tracking Audio Playback Progress by Adding Elapsed Time 

We created a duration state with an initial value of zero, then added an event listener to the audio element for the `loadedMetaData` event. In the event listener callback function, you set the duration state's value to be the audio element's current duration. This ensures that the value of the duration state is only set once the audio element metadata is loaded, allowing you to display the accurate total time of the audio file.

**Think about:** Why do we need to set the duration on the `onLoadedMetadata` event?

"The `onLoadedMetadata` event occurs when metadata for the specified audio/video has been loaded." You can read the docs [here](https://www.w3schools.com/tags/av_event_loadedmetadata.asp) 


 Implementing a Duration State 

We Introduce [MDN Media docs](https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement) and all the APIs. 

In this lesson, we added the `useRef` and created an `audioRef` in our components. We also added the `ref` to the audio element to control it outside of the audio element. We use the `useState` hook, and we created an `isPlaying` state. And finally, we added a `button` that dynamically renders the text as pause and play depending on the `isPlaying` state. On click of that button, we toggle the `isPlaying` state, and depending on that state, we either pause or play it.


Creating a Toggle for Playing and Pausing the Audio

In this lesson we are going to create an `AudioPlayer` component that takes two props `src` and `transcript`, where it returns the audio element and renders the transcript, and we write some pseudo-code for the audio player to reference.

**Think about**: What do we get for free with common HTML elements?

Setup Native Audio and Plan our Audio Player Code

To automate running Lighthouse audits on our application we can add the use of the Lighthouse CI tool to our Continuous Integration suite using GitHub Actions.  By making use of the Lighthouse CI GitHub App we can add to the checks in every Pull Request a report with the score from the audit run on each URL we configure for Lighthouse to audit.

## Resources
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/getting-started.md
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/configuration.md
* https://github.com/apps/lighthouse-ci

Automate Lighthouse Audits with GitHub Actions

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

You’ve probably heard of Lighthouse before as it comes bundled with Chrome DevTools for performing a number of audits on things such as performance, SEO, best practices as well as accessibility. 

We can also use Lighthouse locally on our machines to test our application's rendered pages for accessibility issues before committing changes by using the Lighthouse CI CLI.

## Resources
* https://github.com/GoogleChrome/lighthouse-ci
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/configuration.md

Audit an App's Rendered Pages Locally with Lighthouse CI CLI

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.



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.

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