jsonpatch

README

jsonpatch

As per http://jsonpatch.com JSON Patch is specified in RFC 6902 from the IETF.

JSON Patch allows you to generate JSON that describes changes you want to make to a document, so you don't have to send the whole doc. JSON Patch format is supported by HTTP PATCH method, allowing for standards based partial updates via REST APIs.

go get github.com/appscode/jsonpatch

I tried some of the other "jsonpatch" go implementations, but none of them could diff two json documents and generate format like jsonpatch.com specifies. Here's an example of the patch format:

[
  { "op": "replace", "path": "/baz", "value": "boo" },
  { "op": "add", "path": "/hello", "value": ["world"] },
  { "op": "remove", "path": "/foo"}
]

The API is super simple

example

package main

import (
	"fmt"
	"github.com/appscode/jsonpatch"
)

var simpleA = `{"a":100, "b":200, "c":"hello"}`
var simpleB = `{"a":100, "b":200, "c":"goodbye"}`

func main() {
	patch, e := jsonpatch.CreatePatch([]byte(simpleA), []byte(simpleA))
	if e != nil {
		fmt.Printf("Error creating JSON patch:%v", e)
		return
	}
	for _, operation := range patch {
		fmt.Printf("%s\n", operation.Json())
	}
}

This code needs more tests, as it's a highly recursive, type-fiddly monster. It's not a lot of code, but it has to deal with a lot of complexity.

Documentation

Index

• type ByPath
  • func (a ByPath) Len() int
  • func (a ByPath) Less(i, j int) bool
  • func (a ByPath) Swap(i, j int)
• type JsonPatchOperation
• type Operation
  • func CreatePatch(a, b []byte) ([]Operation, error)
  • func NewPatch(operation, path string, value interface{}) Operation
  • func (j *Operation) Json() string
  • func (j *Operation) MarshalJSON() ([]byte, error)

Types

type ByPath

type ByPath []Operation

func (ByPath) Len

func (a ByPath) Len() int

func (ByPath) Less

func (a ByPath) Less(i, j int) bool

func (ByPath) Swap

func (a ByPath) Swap(i, j int)

type JsonPatchOperation

type JsonPatchOperation = Operation

type Operation

type Operation struct {
	Operation string      `json:"op"`
	Path      string      `json:"path"`
	Value     interface{} `json:"value,omitempty"`
}

func CreatePatch

func CreatePatch(a, b []byte) ([]Operation, error)

CreatePatch creates a patch as specified in http://jsonpatch.com/

'a' is original, 'b' is the modified document. Both are to be given as json encoded content. The function will return an array of JsonPatchOperations

An error will be returned if any of the two documents are invalid.

func NewPatch

func NewPatch(operation, path string, value interface{}) Operation

func (*Operation) Json

func (j *Operation) Json() string

func (*Operation) MarshalJSON

func (j *Operation) MarshalJSON() ([]byte, error)