manipulate-yaml.go

package main

import (
	"fmt"

	"gopkg.in/yaml.v3"
)

var data string = `
# comment
age: 15
name: Gita Hartanto

#this is the hobbies
hobbies:
- eat
- sleep
# yo, another comment
- drink

properties:
  motto: Anda pasti bisa bangkrut
  car: AG1A
`

func main() {
	var x yaml.Node
	err := yaml.Unmarshal([]byte(data), &x)
	if err != nil {
		panic(err)
	}

	// analyze
	for index := 0; index < len(x.Content[0].Content); index += 1 {
		fmt.Println(index, x.Content[0].Content[index].Value, x.Content[0].Content[index].ShortTag())
	}
	fmt.Println("===")

	// set name to "Tobing ora umum"
	for index := 0; index < len(x.Content[0].Content); index += 2 {
		if x.Content[0].Content[index].ShortTag() == "!!str" && x.Content[0].Content[index].Value == "name" {
			x.Content[0].Content[index+1].SetString("Gita Hartanto alias Tobing")
		}
	}

	// translate hobbies to bahasa Indonesia
	for index := 0; index < len(x.Content[0].Content); index += 2 {
		if x.Content[0].Content[index].ShortTag() == "!!str" && x.Content[0].Content[index+1].ShortTag() == "!!seq" && x.Content[0].Content[index].Value == "hobbies" {
			for hobbyIndex := 0; hobbyIndex < len(x.Content[0].Content[index+1].Content); hobbyIndex++ {
				hobbyVal := x.Content[0].Content[index+1].Content[hobbyIndex].Value
				newHobbyVal := hobbyVal
				switch hobbyVal {
				case "eat":
					newHobbyVal = "makan"
				case "sleep":
					newHobbyVal = "tidur"
				case "drink":
					newHobbyVal = "minum"
				}
				x.Content[0].Content[index+1].Content[hobbyIndex].SetString(newHobbyVal)
			}
		}
	}

	// add new hobby
	for index := 0; index < len(x.Content[0].Content); index += 2 {
		if x.Content[0].Content[index].ShortTag() == "!!str" && x.Content[0].Content[index+1].ShortTag() == "!!seq" && x.Content[0].Content[index].Value == "hobbies" {
			var newHobby yaml.Node
			yaml.Unmarshal([]byte("pitching qnet"), &newHobby)
			x.Content[0].Content[index+1].Content = append(x.Content[0].Content[index+1].Content, newHobby.Content[0])
		}
	}

	// change car
	for index := 0; index < len(x.Content[0].Content); index += 2 {
		if x.Content[0].Content[index].ShortTag() == "!!str" && x.Content[0].Content[index+1].ShortTag() == "!!map" && x.Content[0].Content[index].Value == "properties" {
			for property_index := 0; property_index < len(x.Content[0].Content[index+1].Content); property_index++ {
				if x.Content[0].Content[index+1].Content[property_index].Value == "car" {
					x.Content[0].Content[index+1].Content[property_index+1].SetString("AG1A Jaguar")
				}
			}
		}
	}

	// show modified yaml
	b, err := yaml.Marshal(&x)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(b))

	// expected:
	// # comment
	// age: 15
	// name: Gita Hartanto alias Tobing
	// #this is the hobbies
	// hobbies:
	//     - makan
	//     - tidur
	//     # yo, another comment
	//     - minum
	//     - pitching qnet
	// properties:
	//     motto: Anda pasti bisa bangkrut
	//     car: AG1A Jaguar
}