Angular Lazy Loading Implementation

Implement lazy loading for a specific feature module in an Angular application. Lazy loading is a crucial optimization technique that defers the loading of certain modules until they are actually needed by the user. This significantly improves the initial load time of your application, leading to a better user experience, especially for large or complex applications.

Problem Description

Your task is to configure an Angular application to lazily load a feature module. This means that the code for this module should only be downloaded and initialized when the user navigates to a route associated with that module.

Key Requirements:

1. Create a Feature Module: Design a simple Angular feature module (e.g., "Admin Module") with at least one component and a route within it.
2. Configure Lazy Loading: Set up the main application's routing module to lazily load this feature module.
3. Route Configuration: Ensure that navigating to the designated route for the feature module triggers its lazy loading.
4. Verify Loading: Demonstrate that the feature module is indeed loaded only when its route is accessed.

Expected Behavior:

• When the application initially loads, the "Admin Module" code should not be present in the main JavaScript bundle.
• When the user navigates to the route configured for the "Admin Module" (e.g., /admin), the browser should download the "Admin Module"'s code.
• Once loaded, the component within the "Admin Module" should be displayed.

Edge Cases/Considerations:

• Ensure correct path configuration for lazy loading.
• Handle potential errors during module loading (though explicit error handling is not the primary focus of this challenge, be aware of it).

Examples

Example 1: Initial Load

• Input: The Angular application is launched and the user is on the root route (/).
• Output: The initial JavaScript bundle downloaded by the browser is relatively small. The "Admin Module" code is not present. The application displays its default content.
• Explanation: At this stage, the "Admin Module" has not been requested, so Angular defers its loading.

Example 2: Navigating to Lazy Loaded Route

• Input: The user clicks a link or directly navigates to the /admin route.
• Output:
  1. The browser initiates a network request to download the JavaScript chunk for the "Admin Module".
  2. Once the chunk is downloaded and processed, the "Admin Component" is displayed within the application's view.
  3. Subsequent navigations within the application that do not involve the /admin route will not trigger another download of the "Admin Module" code.
• Explanation: The router detects the navigation to /admin, which is configured for lazy loading the "Admin Module". It then fetches and loads the module before rendering its content.

Constraints

• The application must be built using Angular CLI version 8 or higher.
• The solution must be written in TypeScript.
• The lazy-loaded module should be a separate feature module, not part of the root application module.
• No third-party libraries or frameworks are allowed for the core lazy loading mechanism.

Notes

• You will need to create at least three distinct Angular modules: the root AppModule, a FeatureModule (e.g., AdminModule), and an AppRoutingModule.
• Pay close attention to the loadChildren property in your route configuration.
• You can use your browser's developer tools (Network tab) to observe the loading of JavaScript chunks. You should see a new chunk being loaded when you navigate to the lazy-loaded route.
• Consider how you would define a shared module if certain components or services needed to be accessible by both the main app and the lazy-loaded module. (This is an advanced thought, not a strict requirement for this challenge).