WebJSX, WebJSX Router and Magic Loop README for LLMs

webjsx_router_magicloop_llms.txt

WebJSX:
======
# WebJSX

A minimal library for building web applications with JSX and Web Components. It focuses on simplicity, providing just **two core functions**:

- **`createElement`**: Creates virtual DOM elements using JSX.
- **`applyDiff`**: Efficiently applies changes to the real DOM by comparing virtual nodes.

## Examples

There are a few examples on [StackBlitz](https://stackblitz.com/@jeswin/collections/webjsx). If you're impatient (like me), that's probably the easiest way to get started.

- [Todo List](https://stackblitz.com/edit/webjsx-todos)
- [Rotten Tomatoes Mockup](https://stackblitz.com/edit/webjsx-tomatoes)
- [Boring Dashboard](https://stackblitz.com/edit/webjsx-dashboard)

## Installation

Install webjsx via npm:

```sh
npm install webjsx
```

## Getting Started

WebJSX fully supports JSX syntax, allowing you to create virtual DOM elements using `createElement` and update the real DOM with `applyDiff`.

```jsx
import * as webjsx from "webjsx";

// Define a simple virtual DOM element using JSX
const vdom = (
  <div id="main-container">
    <h1>Welcome to webjsx</h1>
    <p>This is a simple example.</p>
  </div>
);

// Select the container in the real DOM
const appContainer = document.getElementById("app");

// Apply the virtual DOM diff to update the real DOM
webjsx.applyDiff(appContainer, vdom);
```

### Defining and Using Web Components with JSX

Let's write a simple Custom Element with JSX.

```jsx
import * as webjsx from "webjsx";

// Define a custom Web Component
class MyElement extends HTMLElement {
  static get observedAttributes() {
    return ["title", "count"];
  }

  constructor() {
    super();
    this._count = 0;
  }

  connectedCallback() {
    this.render();
  }

  attributeChangedCallback(name, oldValue, newValue) {
    if (name === "title" || name === "count") {
      this.render();
    }
  }

  set count(val) {
    this._count = val;
    this.render();
  }

  get count() {
    return this._count;
  }

  render() {
    // Use webjsx's applyDiff to render JSX inside the Web Component
    const vdom = (
      <div>
        <h2>{this.getAttribute("title")}</h2>
        <p>Count: {this.count}</p>
      </div>
    );
    webjsx.applyDiff(this, vdom);
  }
}

// Register the custom element
if (!customElements.get("my-element")) {
  customElements.define("my-element", MyElement);
}

// Create a virtual DOM with the custom Web Component
const vdom = <my-element title="Initial Title" count={10}></my-element>;

// Render the custom Web Component
const appContainer = document.getElementById("app");
webjsx.applyDiff(appContainer, vdom);
```

### Handling Events in JSX

Attach event listeners directly within your JSX using standard HTML event attributes.

```jsx
import * as webjsx from "webjsx";

// Define an event handler
const handleClick = () => {
  alert("Button clicked!");
};

// Create a button with an onclick event
const vdom = <button onclick={handleClick}>Click Me</button>;

// Render the button
const appContainer = document.getElementById("app");
webjsx.applyDiff(appContainer, vdom);
```

### Using Fragments

Group multiple elements without introducing additional nodes to the DOM using `<>...</>` syntax.

```jsx
import * as webjsx from "webjsx";

// Define a custom Web Component using fragments
class MyList extends HTMLElement {
  connectedCallback() {
    const vdom = (
      <>
        <h2>My List</h2>
        <ul>
          <li>Item 1</li>
          <li>Item 2</li>
          <li>Item 3</li>
        </ul>
        <footer>Total items: 3</footer>
      </>
    );
    webjsx.applyDiff(this, vdom);
  }
}

// Register the custom element
if (!customElements.get("my-list")) {
  customElements.define("my-list", MyList);
}

// Render the custom Web Component
const appContainer = document.getElementById("app");
const vdom = <my-list></my-list>;
webjsx.applyDiff(appContainer, vdom);
```

## API Reference

### `createElement(tag, props, children)`

Creates a virtual DOM element.

**JSX calls createElement implicitly:**

```jsx
const vdom = (
  <div id="main-container">
    <h1>Welcome to webjsx</h1>
  </div>
);
```

**Usage (Non-JSX):**

```js
const vdom = webjsx.createElement(
  "div",
  { id: "main-container" },
  webjsx.createElement("h1", null, "Welcome to webjsx")
);
```

### `applyDiff(parent, newVirtualNode)`

Applies the differences between the new virtual node(s) and the existing DOM.

**Usage:**

```jsx
const vdom = <p class="text">Updated Text</p>;
webjsx.applyDiff(appContainer, vdom);
```

### `Fragment`

A special type used to group multiple elements without adding extra nodes to the DOM.

**Usage:**

```jsx
<>
  <span>Item 1</span>
  <span>Item 2</span>
</>
```

### `createDOMElement(vElement)`

You probably won't need to use this directly. But if you want to convert a virtual DOM Element into a real DOM Element you can use `createDOMElement`.

**Usage:**

```js
const vnode = <div>Hello, world!</div>;
const domNode = webjsx.createDOMElement(vnode);
document.body.appendChild(domNode);
```

## Example: Creating a Counter Web Component

```jsx
import * as webjsx from "webjsx";

// Define the custom Web Component
class CounterElement extends HTMLElement {
  static get observedAttributes() {
    return ["title", "count"];
  }

  constructor() {
    super();
    this._count = 0;
  }

  connectedCallback() {
    this.render();
  }

  attributeChangedCallback(name, oldValue, newValue) {
    if (name === "title" || name === "count") {
      this.render();
    }
  }

  set count(val) {
    this._count = val;
    this.render();
  }

  get count() {
    return this._count;
  }

  render() {
    // Render JSX inside the Web Component
    const vdom = (
      <div>
        <h2>{this.getAttribute("title")}</h2>
        <p>Count: {this.count}</p>
        <button onclick={this.increment.bind(this)}>Increment</button>
      </div>
    );
    webjsx.applyDiff(this, vdom);
  }

  increment() {
    this.count += 1;
  }
}

// Register the custom element
if (!customElements.get("counter-element")) {
  customElements.define("counter-element", CounterElement);
}

// Create and render the CounterElement
const vdom = <counter-element title="My Counter" count={0}></counter-element>;

const appContainer = document.getElementById("app");
webjsx.applyDiff(appContainer, vdom);
```

## Advanced: Rendering Suspension

If a class defines the `webjsx_suspendRendering` and `webjsx_resumeRendering` methods, WebJSX will call the former before setting properties and the latter after all properties are set. This allows you to suspend rendering while multiple properties are being set, which would otherwise result in multiple re-renders.

In the following example, for the JSX markup <my-element prop1={10} prop2={20} />, the render() method is called only once after both properties are set:

```ts
class MyElement extends HTMLElement {
  constructor() {
    super();
    this.renderingSuspended = false;
  }

  render() {
    if (!this.renderingSuspended) {
      this.textContent = `Prop1: ${this.getAttribute(
        "prop1"
      )}, Prop2: ${this.getAttribute("prop2")}`;
    }
  }

  __webjsx_suspendRendering() {
    this.renderingSuspended = true;
  }

  __webjsx_resumeRendering() {
    this.renderingSuspended = false;
    this.render(); // Perform the actual rendering
  }
}
```

## TypeScript

### tsconfig.json

Ensure your `tsconfig.json` is set up to handle JSX.

```json
{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "webjsx"
  }
}
```

### Adding Custom Elements to IntrinsicElements (TypeScript)

TypeScript will complain that your Custom Element (such as `<counter-element>`) is not found. That's because it is only aware of standard HTML elements and doesn't know what `<counter-element>` is.

To fix this you need to declare custom elements in a declarations file, such as custom-elements.d.ts:

```ts
import "webjsx";

declare global {
  namespace JSX {
    interface IntrinsicElements {
      "counter-element": {
        count: number;
      };
      "sidebar-component": {
        about: string;
        email: string;
      };
    }
  }
}
```

## Bundling

You can bundle with your favorite bundler, but most apps don't need to.

You can load modules directly on the web page these days:

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <title>WebJsx Test</title>

    <!-- node_modules or wherever you downloaded webjsx -->
    <script type="importmap">
      {
        "imports": {
          "webjsx": "../node_modules/webjsx/dist/index.js",
          "webjsx/jsx-runtime": "../node_modules/webjsx/dist/jsx-runtime.js"
        }
      }
    </script>
    <!-- This is your entry point -->
    <script type="module" src="../dist/index.js"></script>
  </head>

  <body>
    <div id="app"></div>
  </body>
</html>
```

You can see more examples on [StackBlitz](https://stackblitz.com/@jeswin/collections/webjsx).

## Routing

For routing needs, you can use [webjsx-router](https://github.com/webjsx/webjsx-router), a minimal type-safe pattern matching router designed specifically for WebJSX applications.

### Installation

```sh
npm install webjsx-router
```

### Basic Routing Example

```jsx
import * as webjsx from "webjsx";
import { match, goto, initRouter } from "webjsx-router";

// Initialize router with routing logic
const container = document.getElementById("app")!;
initRouter(
  container,
  () =>
    match("/users/:id", (params) => <user-details id={params.id} />) ||
    match("/users", () => <user-list />) ||
    <not-found />
);

// Navigation with goto
goto("/users/123");

// With query parameters
goto("/search", { q: "test", sort: "desc" });
```

### URL Pattern Examples

```jsx
// Static routes
match("/about", () => <about-page />);

// Routes with parameters
match("/users/:id", (params) => <user-details id={params.id} />);

// Query parameters
// URL: /search?q=test&sort=desc
match("/search", (params, query) => (
  <search-results query={query.q} sort={query.sort} />
));
```

The router includes TypeScript support with automatic type inference for parameters and query strings. For more details, check out the [webjsx-router documentation](https://github.com/webjsx/webjsx-router).

## Contributing

Contributions are welcome! Whether it's reporting bugs, suggesting features, or submitting pull requests, your help is appreciated.
Please ensure that your contributions adhere to the project's coding standards and include appropriate tests.

To run the tests:

```sh
npm test
```

## License

WebJSX is open-source software [licensed as MIT](https://raw.githubusercontent.com/webjsx/webjsx/refs/heads/main/LICENSE).

## Support

If you encounter any issues or have questions, feel free to open an issue on [GitHub](https://github.com/webjsx/webjsx/issues) or reach out via Twitter [@jeswin](https://twitter.com/jeswin).


WebJSX Router
=============
# Webjsx Router

A minimal, type-safe pattern matching router for webjsx with zero dependencies. Ideal for building web components with declarative routing.

## Installation

```bash
npm install webjsx-router
```

## Features

- Lightweight and fast pattern matching
- Full TypeScript support with type inference
- URL parameter extraction
- Query string parsing
- Trailing slash handling
- Chain multiple routes with fallbacks
- No external dependencies
- Handles browser navigation events

## Usage

Initialize the router with a root container and render function:

```ts
import { match, goto, initRouter } from "webjsx-router";
import * as webjsx from "webjsx";

// Initialize router with routing logic
const container = document.getElementById("app")!;
initRouter(
  container,
  () =>
    match("/users/:id", (params) => (
      <user-details id={params.id} onBack={() => goto("/users")} />
    )) ||
    match("/users", () => <user-list />) || <not-found />
);
```

### Navigation

Use the `goto` function to navigate between routes:

```ts
import { goto } from "webjsx-router";

// Simple navigation
goto("/users");

// With query parameters
goto("/search", { q: "test", sort: "desc" });
```

### URL Patterns

The router supports URL patterns with named parameters:

```ts
// Static routes
match("/about", () => <about-page />);

// Single parameter
match("/users/:id", (params) => <user-details id={params.id} />);

// Multiple parameters
match("/org/:orgId/users/:userId", (params) => (
  <org-user orgId={params.orgId} userId={params.userId} />
));
```

### Query Parameters

Query strings are automatically parsed and provided to your render function:

```ts
// URL: /search?q=test&sort=desc
match("/search", (params, query) => {
  query.q; // "test"
  query.sort; // "desc"
  return <search-results query={query.q} sort={query.sort} />;
});
```

### Type Safety

The router provides full TypeScript support with automatic type inference:

```ts
// Parameters are fully typed
match("/users/:userId/posts/:postId", (params) => {
  params.userId; // typed as string
  params.postId; // typed as string
  return <user-post {...params} />;
});

// Query parameters are typed as Record<string, string>
match("/users", (params, query) => {
  query.page; // typed as string | undefined
  return <user-list page={query.page} />;
});
```

### Route Chaining

Chain multiple routes with the OR operator (`||`). The last route acts as a fallback:

```ts
match("/users/:id", (params) => <user-details id={params.id} />) ||
  match("/users", () => <user-list />) ||
  match("/about", () => <about-page />) || <not-found />; // Fallback route
```

### Browser Navigation

The router automatically handles browser back/forward navigation and updates the view accordingly. No additional setup required.

### Complete HTML Example

```html
<!DOCTYPE html>
<html>
  <head>
    <title>Webjsx Router Example</title>
  </head>
  <body>
    <div id="app"></div>
    <script type="module">
      import { match, goto, initRouter } from "webjsx-router";
      import * as webjsx from "webjsx";

      // Define custom elements
      class UserList extends HTMLElement {
        connectedCallback() {
          webjsx.applyDiff(
            this,
            <div>
              <h1>Users</h1>
              <button onclick={() => goto("/users/1")}>View User 1</button>
              <button onclick={() => goto("/users/2")}>View User 2</button>
            </div>
          );
        }
      }

      class UserDetails extends HTMLElement {
        static get observedAttributes() {
          return ["id"];
        }

        connectedCallback() {
          this.render();
        }

        attributeChangedCallback() {
          this.render();
        }

        render() {
          const id = this.getAttribute("id");
          webjsx.applyDiff(
            this,
            <div>
              <h1>User {id}</h1>
              <button onclick={() => goto("/users")}>Back to List</button>
            </div>
          );
        }
      }

      class NotFound extends HTMLElement {
        connectedCallback() {
          webjsx.applyDiff(
            this,
            <div>
              <h1>404 Not Found</h1>
              <button onclick={() => goto("/users")}>Go to Users</button>
            </div>
          );
        }
      }

      customElements.define("user-list", UserList);
      customElements.define("user-details", UserDetails);
      customElements.define("not-found", NotFound);

      // Initialize router with routing logic
      const container = document.getElementById("app");
      initRouter(
        container,
        () =>
          match("/users/:id", (params) => <user-details id={params.id} />) ||
          match("/users", () => <user-list />) || <not-found />
      );
    </script>
  </body>
</html>
```

## License

MIT

Magic Loop
==========
# Magic Loop: An experimental Web Component framework

Magic Loop is an experimental approach to managing front-end state using Web Components and Asynchronous Generators. Under the hood, it uses `webjsx`.

1. **Web Components**: All components are Web Components, which you can re-use natively or from any framework.
2. **Asynchronous Generators**: Rendering is done with an asynchronous generator, yielding dynamic JSX views as the state changes.
3. **Declarative Routing**: Define routes and associate them with components using the `webjsx-router` API.

If you want to dive right into code, here's an [HN Homepage example](https://stackblitz.com/edit/magic-loop-hn) on StackBlitz.

## Installation

To use Magic Loop in your project:

```bash
npm install magic-loop webjsx-router webjsx
```

### TypeScript

Ensure your `tsconfig.json` is set up to handle JSX.

```json
{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "webjsx"
  }
}
```

Advanced instructions can be found on [WebJSX](https://webjsx.org).

## Declaring Components

A component in Magic Loop is defined with the `component` function, which takes three parameters: the component's name, an asynchronous generator function (or a regular function), and an optional default properties object. The generator function is where the rendering logic is implemented, yielding views dynamically as the component's state changes. The optional properties object can be used to initialize default settings for the component.

Here's an example of a click-counter component:

```ts
import { component } from "magic-loop";

component("click-counter", async function* (component) {
  let count = 0;

  while (true) {
    yield (
      <div>
        <p>Count: {count}</p>
        <button
          onclick={() => {
            count++;
            component.render();
          }}
        >
          Increment
        </button>
      </div>
    );
  }
});
```

In this example, the `while (true)` loop enables continuous rendering, with the `yield` keyword producing new views whenever the state changes. The `component.render()` method is called to trigger these updates, ensuring that the UI reflects the latest state (in this case, the current count).

In cases where a component's output does not need to update dynamically, you can return a static JSX view right away. This is ideal for simpler components where the content is either fixed or determined only once. For example:

```ts
component("static-component", async function* (component) {
  return (
    <div>
      <h1>Welcome to Magic Loop!</h1>
      <p>This is a static component.</p>
    </div>
  );
});
```

Properties are defined as part of the component declaration, with default values specified in the optional third parameter. Here is an example:

```ts
component(
  "custom-title",
  async function* (component: HTMLElement & { title: string }) {
    yield <h2>{component.title}</h2>;
  },
  { title: "Default Title" }
);
```

This component displays a heading using the `title` property. If no title is provided, the default value "Default Title" is used. For a Web Component to have a prop or an attribute, it must declare them in this manner with default values.

If you want to jump right into the code, you can edit the [HN example on StackBlitz](https://stackblitz.com/edit/magic-loop-hn).

## Shadow DOM Support

Magic Loop components can use Shadow DOM for style encapsulation. To enable Shadow DOM, use the `shadow` option in the component options (fourth parameter):

```ts
component(
  "shadow-example",
  async function* (component) {
    yield <div>Content inside shadow DOM</div>;
  },
  {}, // default props
  { shadow: "open" } // Creates an open shadow root
);
```

You can choose between two Shadow DOM modes:

- `"open"`: Makes the shadow root accessible via element.shadowRoot
- `"closed"`: Creates a closed shadow root (element.shadowRoot will be null)

To add styles to your Shadow DOM, use the `styles` option:

```ts
component(
  "styled-shadow",
  async function* (component) {
    yield <div class="container">Styled content</div>;
  },
  {},
  {
    shadow: "open",
    styles: ".container { color: blue; padding: 10px; }",
  }
);
```

You can also use Constructed StyleSheets with the `adoptedStyleSheets` option:

```ts
const sheet = new CSSStyleSheet();
sheet.replaceSync(".container { color: red; }");

component(
  "adopted-styles-example",
  async function* (component) {
    yield <div class="container">Content with adopted styles</div>;
  },
  {},
  {
    shadow: "open",
    adoptedStyleSheets: [sheet],
  }
);
```

## Lifecycle Methods

Components in Magic Loop support lifecycle methods through the ComponentOptions parameter:

```ts
component(
  "lifecycle-example",
  async function* (component) {
    yield <div>Content</div>;
  },
  {}, // default props
  {
    onConnected: (component) => {
      // Called when component is added to DOM
      console.log("Component connected");
    },
    onDisconnected: (component) => {
      // Called when component is removed from DOM
      console.log("Component disconnected");
    },
  }
);
```

The lifecycle methods are:

- `onConnected`: Called when the component is added to the DOM. Use this to initialize resources, start data fetching, or set up subscriptions.
- `onDisconnected`: Called when the component is removed from the DOM. Use this to clean up resources, cancel pending requests, or remove event listeners.

These methods help manage side effects and resources throughout the component's lifecycle.

## Routing

For routing needs, you can use [webjsx-router](https://github.com/webjsx/webjsx-router), a minimal type-safe pattern matching router designed specifically for WebJSX applications.

### Installation

```sh
npm install webjsx-router
```

### Basic Routing Example

```jsx
import * as webjsx from "webjsx";
import { match, goto, initRouter } from "webjsx-router";

// Initialize router with routing logic
const container = document.getElementById("app")!;
initRouter(
  container,
  () =>
    match("/users/:id", (params) => <user-details id={params.id} />) ||
    match("/users", () => <user-list />) ||
    <not-found />
);

// Navigation with goto
goto("/users/123");

// With query parameters
goto("/search", { q: "test", sort: "desc" });
```

### URL Pattern Examples

```jsx
// Static routes
match("/about", () => <about-page />);

// Routes with parameters
match("/users/:id", (params) => <user-details id={params.id} />);

// Query parameters
// URL: /search?q=test&sort=desc
match("/search", (params, query) => (
  <search-results query={query.q} sort={query.sort} />
));
```

The router includes TypeScript support with automatic type inference for parameters and query strings. For more details, check out the [webjsx-router documentation](https://github.com/webjsx/webjsx-router).

## Building an HN Clone

Let's build a Hacker News (HN) clone using Magic Loop. This example demonstrates how to create a full-featured web application with components, routing, data fetching, and state management.

### Story List - The Home Page

The home page displays a curated list of top stories from Hacker News. When the component mounts, it fetches the IDs of top stories from the HN API, then retrieves detailed data for the top stories. Each story is displayed with its title, score, author link, and comment count. The component handles loading states and provides clear feedback to users while data is being fetched.

```ts
component("story-list", async function* (component: HTMLElement & Component) {
  let stories = null as Story[] | null;

  const fetchTopStories = async (limit = 30) => {
    const topIds = await fetch(
      "https://hacker-news.firebaseio.com/v0/topstories.json"
    ).then((res) => res.json());
    const sliced = topIds.slice(0, limit);
    stories = await Promise.all(
      sliced.map((id: number) =>
        fetch(`https://hacker-news.firebaseio.com/v0/item/${id}.json`).then(
          (r) => r.json()
        )
      )
    );
    component.render();
  };

  fetchTopStories();

  while (true) {
    if (stories === null) {
      yield (
        <div style="padding: 2em; background: gray; border-radius: 8px">
          Loading top stories...
        </div>
      );
    } else {
      return (
        <div>
          <hn-header />
          <div class="story-list">
            {stories.slice(0, 30).map((story: Story, index: number) => (
              <div class="story-list-item">
                <span class="rank">{index + 1}.</span>
                <span>
                  <a
                    class="title-link"
                    href="#"
                    onclick={() => goto(`/story/${story.id}`)}
                  >
                    {story.title}
                  </a>
                  {story.url && (
                    <span class="meta">
                      {" "}
                      <a
                        href={story.url}
                        class="host"
                        target="_blank"
                        rel="noopener noreferrer"
                      >
                        ({new URL(story.url).hostname.replace("www.", "")})
                      </a>
                    </span>
                  )}
                </span>
                <div class="meta" style="margin-left: 2em">
                  {story.score} points by <user-link username={story.by} />{" "}
                  <a href="#" onclick={() => goto(`/story/${story.id}`)}>
                    {story.descendants || 0} comments
                  </a>
                </div>
              </div>
            ))}
          </div>
        </div>
      );
    }
  }
});
```

### Story Detail Page

When a user clicks on a story title, they're taken to the story detail page. This component fetches and displays comprehensive information about a single story, including its title (linked to the original URL), score, author, and the full comment thread. It provides a back navigation link and gracefully handles cases where the story might not be found.

```ts
component(
  "story-detail",
  async function* (component: HTMLElement & Component & { storyid: number }) {
    let story: Story | null = null;

    const fetchData = async (): Promise<Story | null> => {
      try {
        const result = await fetchItem<Story>(component.storyid);
        return result;
      } catch {
        return null;
      }
    };

    story = await fetchData();

    while (true) {
      if (!story?.id) {
        yield (
          <div>
            <a class="back-link" href="#" onclick={() => goto("/")}>
              Back
            </a>
            <div>Story not found.</div>
          </div>
        );
      } else {
        return (
          <div>
            <a class="back-link" href="#" onclick={() => goto("/")}>
              &larr; Back
            </a>
            <h2>
              <a href={story.url} target="_blank" rel="noopener noreferrer">
                {story.title}
              </a>
            </h2>
            <div class="meta">
              {story.score} points by <user-link username={story.by} /> |{" "}
              {story.descendants || 0} comments
            </div>
            <hr />
            <comment-thread parentid={story.id} />
          </div>
        );
      }
    }
  },
  { storyid: 0 }
);
```

### Comment Thread Component

This component manages the top-level structure of a story's comment thread. It fetches the list of comments for a given story and renders them as a discussion thread. If there are no comments, it displays an appropriate message.

```ts
component(
  "comment-thread",
  async function* (component: HTMLElement & Component & { parentid: number }) {
    let parentData: CommentData | null = null;

    const fetchData = async (): Promise<CommentData | null> => {
      try {
        const result = await fetchItem<CommentData>(component.parentid);
        return result;
      } catch {
        return null;
      }
    };

    parentData = await fetchData();

    while (true) {
      if (!parentData?.kids?.length) {
        yield <div>No comments yet.</div>;
      } else {
        return (
          <div class="comments-container">
            {parentData.kids.map((kidId: number) => (
              <comment-item commentid={kidId} />
            ))}
          </div>
        );
      }
    }
  },
  { parentid: 0 }
);
```

### Comment Item Component

This component handles the display of individual comments, including any nested replies. It supports text comments and implements indentation for nested comments. The component gracefully handles deleted comments and missing content.

```ts
component(
  "comment-item",
  async function* (component: HTMLElement & Component & { commentid: number }) {
    let commentData: CommentData | null = null;

    const fetchData = async (): Promise<CommentData | null> => {
      try {
        const result = await fetchItem<CommentData>(component.commentid);
        return result;
      } catch {
        return null;
      }
    };

    commentData = await fetchData();

    while (true) {
      if (!commentData?.id) {
        yield <div class="comment">(deleted)</div>;
      } else {
        return (
          <div class="comment">
            <div class="comment-meta">
              {commentData.by ? (
                <user-link username={commentData.by} />
              ) : (
                "(deleted)"
              )}
            </div>
            <div
              class="comment-text"
              {...{ innerHTML: commentData.text || "(no text)" }}
            ></div>
            {commentData.kids && commentData.kids.length > 0 && (
              <div class="nested-comments" style="margin-left: 20px;">
                {commentData.kids.map((kidId: number) => (
                  <comment-item commentid={kidId} />
                ))}
              </div>
            )}
          </div>
        );
      }
    }
  },
  { commentid: 0 }
);
```

### User Profile Page

The user profile page displays the user's karma score, account creation date, about section (if available), and a list of their recent submissions. The component implements type guards to ensure data integrity and handles missing or invalid user data appropriately.

```ts
component(
  "user-profile",
  async function* (component: HTMLElement & Component & { username: string }) {
    let userData: UserData | null = null;
    let userStories: Story[] = [];

    const fetchUser = async (username: string): Promise<UserData> => {
      return fetch(
        `https://hacker-news.firebaseio.com/v0/user/${username}.json`
      ).then((r) => r.json());
    };

    const fetchData = async (): Promise<[UserData | null, Story[]]> => {
      try {
        const user = await fetchUser(component.username);
        const submissions = user.submitted || [];
        const stories = await Promise.all(
          submissions.slice(0, 10).map((id) => fetchItem<Story>(id))
        );
        return [
          user,
          stories.filter(
            (s): s is Story =>
              typeof s?.id === "number" &&
              typeof s?.title === "string" &&
              typeof s?.score === "number" &&
              typeof s?.by === "string"
          ),
        ];
      } catch {
        return [null, []];
      }
    };

    [userData, userStories] = await fetchData();

    while (true) {
      if (!userData) {
        yield (
          <div>
            <a class="back-link" href="#" onclick={() => goto("/")}>
              Back
            </a>
            <div>User not found.</div>
          </div>
        );
      } else {
        return (
          <div>
            <a class="back-link" href="#" onclick={() => goto("/")}>
              &larr; Back
            </a>
            <h2>User: {userData.id}</h2>
            <div class="user-info">
              <p>Karma: {userData.karma}</p>
              <p>
                Created:{" "}
                {new Date(userData.created * 1000).toLocaleDateString()}
              </p>
              {userData.about && (
                <div class="about">
                  <h3>About</h3>
                  <div {...{ innerHTML: userData.about }}></div>
                </div>
              )}
            </div>
            <div class="user-submissions">
              <h3>Recent Submissions</h3>
              {userStories.map((story) => (
                <div class="story-list-item">
                  <a href="#" onclick={() => goto(`/story/${story.id}`)}>
                    {story.title}
                  </a>
                  <div class="meta">
                    {story.score} points | {story.descendants || 0} comments
                  </div>
                </div>
              ))}
            </div>
          </div>
        );
      }
    }
  },
  { username: "" }
);
```

### User Link Component

A utility component used throughout the application to create consistent user profile links. It takes a username prop and renders a clickable link that navigates to that user's profile page.

```ts
component(
  "user-link",
  async function* (component: HTMLElement & Component & { username: string }) {
    return (
      <a href="#" onclick={() => goto(`/user/${component.username}`)}>
        {component.username}
      </a>
    );
  },
  { username: "" }
);
```

### Header Component

The header component implements the classic Hacker News navigation bar, including the Y Combinator logo and navigation links. This component provides consistent navigation across all pages of the application.

```ts
component("hn-header", async function* (component: HTMLElement & Component) {
  while (true) {
    yield (
      <div class="hn-header">
        <div class="hn-header-content">
          <a href="#" class="hn-logo" onclick={() => goto("/")}>
            Y
          </a>
          <a href="#" class="hn-header-text" onclick={() => goto("/")}>
            <b>Hacker News</b>
          </a>
          <a href="#" class="hn-header-link">
            new
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            past
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            comments
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            ask
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            show
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            jobs
          </a>
          <span class="hn-header-separator">|</span>
          <a href="#" class="hn-header-link">
            submit
          </a>
        </div>
      </div>
    );
  }
});
```

## License

MIT



Notes:
======
MagicLoop is a higher level framework built on the WebJSX Web Components framework. This is what you need to use to make components. For routing, use WebJSX Router.