Bits of .NET

🧩 Web Components = Reusable Elements

Framework components are tied. Web Components are framework-agnostic. Reusable, encapsulated, standards-based.

📝 Web Component Basics

// Custom Element
class MyComponent extends HTMLElement {
    constructor() {
        super();
        this.attachShadow({ mode: 'open' });
    }
    
    connectedCallback() {
        this.render();
    }
    
    render() {
        this.shadowRoot.innerHTML = `
            <style>
                :host {
                    display: block;
                    padding: 20px;
                    background: #f0f0f0;
                    border-radius: 8px;
                }
            </style>
            <div>
                <h2><slot name="title">Default Title</slot></h2>
                <p><slot>Default content</slot></p>
            </div>
        `;
    }
}

// Register component
customElements.define('my-component', MyComponent);

// Usage in HTML
<my-component>
    <span slot="title">Hello World</span>
    <p>This is custom content.</p>
</my-component>

🎯 Advanced Components

// With properties and attributes
class UserCard extends HTMLElement {
    static get observedAttributes() {
        return ['name', 'email', 'avatar'];
    }
    
    constructor() {
        super();
        this.attachShadow({ mode: 'open' });
        this._name = '';
        this._email = '';
        this._avatar = '';
    }
    
    attributeChangedCallback(name, oldValue, newValue) {
        if (name === 'name') this._name = newValue;
        if (name === 'email') this._email = newValue;
        if (name === 'avatar') this._avatar = newValue;
        this.render();
    }
    
    render() {
        this.shadowRoot.innerHTML = `
            <style>
                .card {
                    border: 1px solid #ddd;
                    border-radius: 8px;
                    padding: 16px;
                    display: flex;
                    align-items: center;
                    gap: 16px;
                }
                img {
                    width: 64px;
                    height: 64px;
                    border-radius: 50%;
                }
            </style>
            <div class="card">
                <img src="${this._avatar}" alt="${this._name}">
                <div>
                    <h3>${this._name}</h3>
                    <p>${this._email}</p>
                </div>
            </div>
        `;
    }
}

customElements.define('user-card', UserCard);

💡 Web Component Tips

• Use Shadow DOM for encapsulation
• Define observed attributes
• Use slots for content projection
• Dispatch custom events
• Use with any framework