How to implement caching using etag in angular?

@shyann 

To implement caching using ETags in Angular, you can follow these steps:

1. Set up the ETag header in your backend API to uniquely identify each version of a resource.
2. In your Angular application, make HTTP requests to the backend API that include the If-None-Match header with the ETag value received from the previous response.
3. When a response is received from the backend API, check if the response status is 304 Not Modified. If it is, this means that the resource has not changed since the last request and you can use the cached response data.
4. If the response status is not 304 Not Modified, store the new ETag value in memory for future requests.
5. Implement a caching strategy to store the response data in memory or in a caching service such as localStorage or sessionStorage. This will allow you to access the cached data when a request is made with the same ETag value.

By implementing caching using ETags in Angular, you can reduce network traffic and improve the performance of your application by serving cached resources when they have not been modified.