jsonutil

Documentation

Overview

Package jsonutil contains various utilities for dealing with json data.

Index

• func Indent(jsonStr string) (string, error)
• func Marshal(obj any) (string, error)
• func MarshalIndent(obj any) (string, error)
• func Remarshal(obj any, remarshalledObj any) error
• func Unmarshal(jsonContent string, dest any) error
• func UnmarshalFile(filePath string, dest any) error

Examples

• Indent
• Marshal
• Remarshal

Functions

func Indent

func Indent(jsonStr string) (string, error)

Indent indents a json string.

Example

type Road struct {
	Name   string
	Number int
}

roads := []Road{
	{Name: "Diamond Fork", Number: 29},
	{Name: "Sheep Creek", Number: 51},
}

b, err := Marshal(roads)
if err != nil {
	log.Fatal(err)
}

out, err := Indent(b)
if err != nil {
	log.Fatal(err)
}

fmt.Println(out)

Output:
[
  {
    "Name": "Diamond Fork",
    "Number": 29
  },
  {
    "Name": "Sheep Creek",
    "Number": 51
  }
]

func Marshal

func Marshal(obj any) (string, error)

Marshal marshals an object to a json string. Returns empty string if marshal fails.

Example

type ColorGroup struct {
	ID     int
	Name   string
	Colors []string
}

group := ColorGroup{
	ID:     1,
	Name:   "Reds",
	Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
}

b, err := Marshal(group)
if err != nil {
	fmt.Println("error:", err)
}

fmt.Println(b)

Output:
{"ID":1,"Name":"Reds","Colors":["Crimson","Red","Ruby","Maroon"]}

func MarshalIndent

func MarshalIndent(obj any) (string, error)

MarshalIndent is like Marshal but applies Indent to format the output. Returns empty string if marshal fails.

func Remarshal

func Remarshal(obj any, remarshalledObj any) error

Remarshal marshals an object to Json then parses it back to another object. This is useful for example when we want to go from map[string]any to a more specific struct type or if we want a deep copy of the object.

Example

type ColorGroup struct {
	ID     int
	Name   string
	Colors []string
}

group := ColorGroup{
	ID:     1,
	Name:   "Reds",
	Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
}

var newGroup ColorGroup

err := Remarshal(group, &newGroup)
if err != nil {
	fmt.Println("error:", err)
}

out, err := Marshal(newGroup)
if err != nil {
	fmt.Println("error:", err)
}

fmt.Println(out)

Output:
{"ID":1,"Name":"Reds","Colors":["Crimson","Red","Ruby","Maroon"]}

func Unmarshal

func Unmarshal(jsonContent string, dest any) error

Unmarshal unmarshals the content in string format to an object.

func UnmarshalFile

func UnmarshalFile(filePath string, dest any) error

UnmarshalFile reads the content of a file then Unmarshals the content to an object.