Implementing an Angular App Shell

This challenge focuses on implementing an App Shell pattern in Angular. An App Shell is a minimal, lightweight UI that loads quickly to provide an immediate user experience, even before the main application content is ready. This is crucial for improving perceived performance and user engagement, especially on slower networks or devices.

Problem Description

Your task is to create a basic App Shell for an Angular application. This App Shell should consist of a header, a navigation area, and a placeholder for the main content. The goal is to have this shell load and display instantly, giving the user a sense of a responsive application.

Key Requirements:

• Header Component: Create a reusable Angular component for the application header (e.g., containing the app title and logo).
• Navigation Component: Create a reusable Angular component for the main navigation (e.g., a sidebar or top navigation bar with placeholder links).
• Main Content Placeholder: Designate a specific area within the main layout where the actual application content will be loaded dynamically.
• Layout Structure: Implement a basic layout that accommodates the header, navigation, and content placeholder. This could be a common pattern like a fixed header with a sidebar and content area.
• Styling: Apply basic CSS to make the App Shell visually distinct and demonstrate the layout.
• No Dynamic Content Loading (for this challenge): For the purpose of this exercise, you do not need to implement actual routing or dynamic content loading. The focus is solely on the static App Shell structure and its quick rendering.

Expected Behavior:

When the application loads, the App Shell (header, navigation, and content placeholder) should be immediately visible. There should be no significant delay before the basic structure of the application appears.

Edge Cases to Consider:

• Responsiveness: While not a primary focus, consider how the basic layout might adapt to different screen sizes (e.g., a sidebar collapsing on smaller screens).

Examples

Example 1: Basic App Shell Layout

Input: No specific input, as this is a structural implementation.

Output:
A rendered Angular component displaying:
- A header bar at the top with "My App Title".
- A navigation area on the left side with placeholder links like "Home", "About", "Contact".
- A main content area to the right of the navigation, indicating "Content will load here...".

Explanation: The components are composed to create the shell. The header is fixed, and the navigation and content areas occupy the remaining space.

Example 2: Minimal Styling

Input: N/A

Output:
Visual representation of the App Shell with:
- Header: Distinct background color.
- Navigation: Different background color, placeholder links styled as basic buttons or list items.
- Content Area: Borders to define its space.

Explanation: Basic CSS is applied to differentiate the sections and make the layout clear.

Constraints

• Angular Version: Use Angular v14 or later.
• Language: Solution must be in TypeScript.
• Component Structure: Each part of the App Shell (header, navigation) should be implemented as separate, reusable Angular components.
• No External Libraries (for core functionality): Do not rely on external UI component libraries for the core App Shell structure. Use plain CSS for styling.
• Performance: The App Shell should be designed for minimal load time. Avoid heavy computations or complex asynchronous operations during its initial rendering.

Notes

• Think about how you would structure your components (HeaderComponent, NavigationComponent) and how they would be integrated into a parent component (e.g., AppComponent or a dedicated ShellComponent).
• Consider using CSS Flexbox or Grid for layout management.
• The "placeholder" for content is key. For this challenge, it can simply be static text or a visually distinct area.
• The goal is to simulate the initial rendering experience before any complex data fetching or routing occurs.