jsonpath

README

JsonPath

A golang implementation of JsonPath syntax. follow the majority rules in http://goessner.net/articles/JsonPath/ but also with some minor differences.

this library is till bleeding edge, so use it at your own risk. :D

Golang Version Required: 1.5+

Get Started

go get github.com/oliveagle/jsonpath

example code:

import (
    "github.com/oliveagle/jsonpath"
    "encoding/json"
)

var json_data interface{}
json.Unmarshal([]byte(data), &json_data)

res, err := jsonpath.JsonPathLookup(json_data, "$.expensive")

//or reuse lookup pattern
pat, _ := jsonpath.Compile(`$.store.book[?(@.price < $.expensive)].price`)
res, err := pat.Lookup(json_data)

Operators

referenced from github.com/jayway/JsonPath

Operator	Supported	Description
$	Y	The root element to query. This starts all path expressions.
@	Y	The current node being processed by a filter predicate.
*	X	Wildcard. Available anywhere a name or numeric are required.
..	X	Deep scan. Available anywhere a name is required.
.	Y	Dot-notated child
['' (, '')]	X	Bracket-notated child or children
[ (, )]	Y	Array index or indexes
[start:end]	Y	Array slice operator
[?()]	Y	Filter expression. Expression must evaluate to a boolean value.

Examples

given these example data.

{
    "store": {
        "book": [
            {
                "category": "reference",
                "author": "Nigel Rees",
                "title": "Sayings of the Century",
                "price": 8.95
            },
            {
                "category": "fiction",
                "author": "Evelyn Waugh",
                "title": "Sword of Honour",
                "price": 12.99
            },
            {
                "category": "fiction",
                "author": "Herman Melville",
                "title": "Moby Dick",
                "isbn": "0-553-21311-3",
                "price": 8.99
            },
            {
                "category": "fiction",
                "author": "J. R. R. Tolkien",
                "title": "The Lord of the Rings",
                "isbn": "0-395-19395-8",
                "price": 22.99
            }
        ],
        "bicycle": {
            "color": "red",
            "price": 19.95
        }
    },
    "expensive": 10
}

example json path syntax.

jsonpath	result
$.expensive	10
$.store.book[0].price	8.95
$.store.book[-1].isbn	"0-395-19395-8"
$.store.book[0,1].price	[8.95, 12.99]
$.store.book[0:2].price	[8.95, 12.99, 8.99]
$.store.book[?(@.isbn)].price	[8.99, 22.99]
$.store.book[?(@.price > 10)].title	["Sword of Honour", "The Lord of the Rings"]
$.store.book[?(@.price < $.expensive)].price	[8.95, 8.99]
$.store.book[:].price	[8.9.5, 12.99, 8.9.9, 22.99]
$.store.book[?(@.author =~ /(?i).*REES/)].author	"Nigel Rees"

Note: golang support regular expression flags in form of (?imsU)pattern

Documentation

Index

• Variables
• func JsonPathLookup(obj interface{}, jpath string) (interface{}, error)
• type Compiled
  • func Compile(jpath string) (*Compiled, error)
  • func MustCompile(jpath string) *Compiled
  • func (c *Compiled) Lookup(obj interface{}) (interface{}, error)
  • func (c *Compiled) String() string

Variables

var ErrGetFromNullObj = errors.New("get attribute from null object")

Functions

func JsonPathLookup

func JsonPathLookup(obj interface{}, jpath string) (interface{}, error)

Types

type Compiled

type Compiled struct {
	// contains filtered or unexported fields
}

func Compile

func Compile(jpath string) (*Compiled, error)

func MustCompile

func MustCompile(jpath string) *Compiled

func (*Compiled) Lookup

func (c *Compiled) Lookup(obj interface{}) (interface{}, error)

func (*Compiled) String

func (c *Compiled) String() string