json-where

🔍 Transparent query, pointer and path descriptors for JSON

---

json-where converges the following standards and libraries in order to help normalize JSON query/addressing descriptors:

• JsonPath
  • Specification: http://goessner.net/articles/JsonPath/
  • Library: https://www.npmjs.com/package/jsonpath
• JsonPointer
  • Specification: http://tools.ietf.org/html/draft-ietf-appsawg-json-pointer-08
  • Library: https://www.npmjs.com/package/jsonpointer
• JsonQuery
  • Library: https://www.npmjs.com/package/json-query

The goal is to increase developer transparency and to provide a unified interface for matching related JSON data.

json-where's simple interface spares developers from having to:

1. decide between which query/addressing specifications(s) to support in their projects
2. write an interface for when more than one standard needs support
3. bottleneck integrators of their library into a certain specificaton
4. write a mechanism that provides a consistent return format (e.g. array vs. element)

Installation

npm install json-where

Usage

Implicit

This example shows how to use the main feature of json-where, which is being able to provide any descriptor string to $.

The $ "operator" will automatically imply the correct specification to use based on the descriptor itself:

import $ from 'json-where'
 
const data = {
  foo: {
    bar: 'baz'
  }
}
 
let query   = $('foo.bar').use(data).get()   // 'baz'
let path    = $('$.foo.bar').use(data).get() // 'baz'
let pointer = $('/foo/bar').use(data).get()  // 'baz'

If you want to be slightly more concise you can avoid calling use:

let query   = $('foo[bar]', data).get()  // 'baz'
let path    = $('$.foo.bar', data).get() // 'baz'
let pointer = $('/foo/bar', data).get()  // 'baz'

Explicit

You may also, of course, access and use each specification individually:

import { query, path, pointer } from 'json-where'
 
query('foo[bar]', data).get()   // 'baz'
path('$.foo.bar', data).get()   // 'baz'
pointer('/foo/bar', data).get() // 'baz'

Collections

You can easily specify whether or not you should expect a single object or a collection:

$('foo[bar]', data).one() // 'baz'
$('foo[bar]', data).all() // ['baz']

A couple of common utility methods are also defined for working with collections:

$('foo[bar]', data).count() // 1
$('foo[bar]', data).any()   // true
$('bar[baz]', data).any()   // false

Identification

You can infer the specification directly from the descriptor itself via which:

which('foo[bar]')  // 'json-query'
which('$.foo.bar') // 'json-path'
which('/foo/bar')  // 'json-pointer'

Update

Currently only json-pointer supports updating values via descriptors:

const path = pointer('/foo/bar', data)
 
path.get()      // 'bar'
path.set('zab') // ...
path.get()      // 'zab'