Jsonpath-proxy NPM

JSONPath

JSONPath expressions as first class JS object properties

Proxies jsonpath queries as JS object property chain

Usage

const $ = require('jsonpath-proxy')(json)
const result = $.path["[query]"]

Query Example

const jsonpath = require('jsonpath-proxy')

var cities = [
  { name: "London", "population": 8615246 },
  { name: "Berlin", "population": 3517424 },
  { name: "Madrid", "population": 3165235 },
  { name: "Rome",   "population": 2870528 }
];

var $ = jsonpath.$(cities);
var names = $['..'].name;

// [ "London", "Berlin", "Madrid", "Rome" ]

The same example with jsonpath

var cities = [
  { name: "London", "population": 8615246 },
  { name: "Berlin", "population": 3517424 },
  { name: "Madrid", "population": 3165235 },
  { name: "Rome",   "population": 2870528 }
];

const jsonpath = require('jsonpath-proxy') // same as require('jsonpath')
var names = jsonpath.query(cities, '$..name');

// [ "London", "Berlin", "Madrid", "Rome" ]

Install

Install from npm:

$ npm install jsonpath-proxy

JSONPath Syntax

Here are syntax and examples adapted from Stefan Goessner's original post introducing JSONPath in 2007.

JSONPath	Description
`$`	The root object/element
`@`	The current object/element
`.`	Child member operator
`..`	Recursive descendant operator; JSONPath borrows this syntax from E4X
`*`	Wildcard matching all objects/elements regardless their names
`[]`	Subscript operator
`[,]`	Union operator for alternate names or array indices as a set
`[start:end:step]`	Array slice operator borrowed from ES4 / Python
`?()`	Applies a filter (script) expression via static evaluation
`()`	Script expression via static evaluation

Given this sample data set, see example expressions below:

{
  "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
    }
  }
}

Example jsonpath-proxy.$ expressions:

JSONPath	Description
`$.store.book["*"].author`	The authors of all books in the store
`$[".."].author`	All authors
`$.store.["*"]`	All things in store, which are some books and a red bicycle
`$.store[".."].price`	The price of everything in the store
`$[".."]book[2]`	The third book
`$[".."]book("[(@.length-1)]"]`	The last book via script subscript
`$[".."]book["[-1:]"]`	The last book via slice
`$[".."]book["[0,1]"]`	The first two books via subscript union
`$[".."]book["[:2]"]`	The first two books via subscript array slice
`$[".."]book["[?(@.isbn)]"]`	Filter all books with isbn number
`$[".."]book["[?(@.price<10)]"]`	Filter all books cheaper than 10
`$[".."]book["[?(@.price==8.95)]"]`	Filter all books that cost 8.95
`$[".."]book["[?(@.price<30 && @.category=="fiction")]"]`	Filter all fiction books cheaper than 30
`$[".."]["*"]`	All members of JSON structure

Example jsonpath.query expressions:

JSONPath	Description
`$.store.book[*].author`	The authors of all books in the store
`$..author`	All authors
`$.store.*`	All things in store, which are some books and a red bicycle
`$.store..price`	The price of everything in the store
`$..book[2]`	The third book
`$..book[(@.length-1)]`	The last book via script subscript
`$..book[-1:]`	The last book via slice
`$..book[0,1]`	The first two books via subscript union
`$..book[:2]`	The first two books via subscript array slice
`$..book[?(@.isbn)]`	Filter all books with isbn number
`$..book[?(@.price<10)]`	Filter all books cheaper than 10
`$..book[?(@.price==8.95)]`	Filter all books that cost 8.95
`$..book[?(@.price<30 && @.category=="fiction")]`	Filter all fiction books cheaper than 30
`$..*`	All members of JSON structure