mrhwick/partialmarshal

A Go library for JSON marshaling with extra payloads

PartialMarshal

A Go library for JSON marshaling with extra payloads.

Standard Go JSON marshaling into a struct discards any unmatching fields from the JSON payload. In some use cases, the developer does not want to discard this extra payload data. This library provides a familiar interface for performing marshaling and unmarshaling while keeping any extra data for use by the calling code.

Install

go get github.com/mrhwick/partialmarshal

Usage and Examples

Just like the standard library json package, partialmarshal provides a simple pair of functions for marshaling and unmarshaling of JSON-formatted data into and out of structs.

When a user wants to use partialmarshal to hold onto extra data from a JSON payload, they may simply add the partialmarshal.Extra type as an embedded type in their struct. This embedded type is used by the partialmarshal library for storage of any data from the provided JSON that doesn't match a field of that struct.

type Person struct {
	Name string
	FavoriteFood string `json:"favorite_food"`
	partialmarshal.Extra
}

jsonData := []bytes(`{"name": "gopher", "favorite_food": "Pizza", "age": 25}`)

// Unmarshaling
// => Person{Name: "gopher", FavoriteFood: "Pizza", partialmarshal.Extra{"age":25}}
var p Person
partialmarshal.Unmarshal(jsonData, &p)

// Marshaling
// => `{"name": "gopher", "favorite_food": "Salad", "age" 25}`
p.FavoriteFood = "Salad"
result, err := partialmarshal.Marshal(p)