Handling Null JSON Arrays in Go - Custom Marshaler

handling-null-json-arrays-in-go-custom-marshaler.go

package main

import (
	"encoding/json"
	"fmt"
)

// Bag holds items
type Bag struct {
	Items []string
}

// MarshalJSON initializes nil slices and then marshals the bag to JSON
func (b Bag) MarshalJSON() ([]byte, error) {
	type Alias Bag
	
	a := struct {
		Alias
	}{
		Alias:    (Alias)(b),
	}

	if a.Items == nil {
		a.Items = make([]string, 0)
	}

	return json.Marshal(a)
}

// PrintJSON converts payload to JSON and prints it
func PrintJSON(payload interface{}) {
	response, _ := json.Marshal(payload)
	fmt.Printf("%s\n", response)
}


func main() {
	bag1 := Bag{}
	PrintJSON(bag1)
}