embedded_structs.go

// run with: go run embedded_structs.go
package main

import (
	"encoding/json"
	"fmt"
)

type ProductFields struct {
	ID           uint   `json:"id"`
	Name         string `json:"name"`
	CurrentPrice string `json:"current_price"`
	IsOnSale     bool   `json:"is_on_sale"`
}

type Product struct {
	ID uint `json:"id"`
	ProductFields
}

type Variant struct {
	ID                 uint   `json:"id"`
	VariantDescription string `json:"variant"`
	ProductFields
}

func jsonDump(label string, thingy interface{}) []byte {
	serialized, _ := json.Marshal(thingy)
	fmt.Printf(label+" as JSON:\n  %s\n", serialized)
	return serialized
}

func main() {
	fields := ProductFields{
		ID:           9876,
		Name:         "Grabthar's Hammer",
		CurrentPrice: "59.99",
		IsOnSale:     false,
	}
	jsonDump("Product fields", fields)

	p := Product{
		ID:            123,
		ProductFields: fields,
	}
	jsonDump("Product", p)

	v := Variant{
		ID:                 8181,
		VariantDescription: "Size: Large / Color: Mauve",
		ProductFields:      fields,
	}
	variantJson := jsonDump("Variant", v)

	newVariant := Variant{}
	json.Unmarshal(variantJson, &newVariant)
	fmt.Printf("Variant serialized from JSON\n  [ID: %d] [Name: %s] [Price: %s] [On sale? %t] [Variant: %s]\n",
		newVariant.ID, newVariant.Name, newVariant.CurrentPrice, newVariant.IsOnSale, newVariant.VariantDescription)
}