Let's examine the products.go source file in the endpoints folder:

package endpoints

import (
  "encoding/json"
  "net/http"

  "github.com/EngineerKamesh/igb/igweb/common"
)

func GetProductsEndpoint(env *common.Env) http.Handler {
  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    products := env.DB.GetProducts()
    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(products)
  })
}

Inside the GetProductsEndpoint function, we first fetch the slice of products that will be displayed on the client-side products page by calling the GetProducts method of the datastore object, env.DB. We then set a header to indicate that the server response will be in JSON format. Finally, we use a JSON encoder to encode the slice of products as JSON data and write it out using the the http.ResponseWriter, w.