Understanding the Use of 'environment.ts' in Angular

Angular, a robust front-end framework, utilizes different files for managing various aspects of the application. One such important file is the 'environment.ts'.

The environment.ts file in Angular is primarily used to store global variables. These variables include anything that need to be accessible from anywhere within the Angular application. This includes server URLs, access tokens, app version, feature flags or production and development environment settings, among others.

Practical Example

For instance, suppose you're building an application that communicates with an API. The base URL for the API service could vary depending on whether your application is in development or production stage. In a case like this, you can use the environment.ts file to set these different values.

export const environment = {
  production: false,
  apiUrl: 'http://localhost:3000/api'
};

In the above code, you have specified your API base URL for the development environment. You can create a different environment.prod.ts file for your production environment, with the production flag set to true and a different API base URL.

export const environment = {
  production: true,
  apiUrl: 'https://my-live-app.com/api'
};

This allows you to easily switch the variables based on the environment — development or production — without needing to manually change the values.

Best Practices

When using the environment file:

• Avoid sensitive data: While it's tempting to put all global variables in the environment.ts file, it's not recommended to store sensitive data like API keys or passwords. That's because these files can end up in the client's browser, hence, a potential security breach.
• Use version control: It's ideal to keep the environment.ts file and its variations under version control. However, each developer or team may have a different variant of the configuration file; in such cases, make use of .gitignore to avoid committing these changes.

To sum it up, the 'environment.ts' file in Angular plays a useful role in managing different global aspects of an application, enhancing the scalability, maintainability and adaptability of the application across various deployment environments. However, it is likewise important to keep the best practices in mind while using it.