Pointer

Simple library for getting and setting object values via JSON Pointer or dot-delimited formats.

Highlights

• 🔥 Zero dependencies
• 💻 Works in browser
• 🗜 Tidy and compact, only ~500 bytes minified uncompressed
• ⚡️ Blazing fast

Usage

import * as pointer from '@flexent/pointer';

const object = {
    foo: {
        items: [
            { bar: 'one' },
            { bar: 'two' },
            { bar: 'three' },
        ]
    }
};

// If pointer starts with /, then it's interpreted
// as RFC6901 compliant JSON Pointer
pointer.get(object, '/foo/items/1/bar'); // 'two'

// Otherwise it's a dot-delimited path
pointer.get(object, 'foo.items.0'); // { bar: 'one' }

// Set modifies the object, creating additional objects and arrays as needed
const newObj = {}
pointer.set(newObj, 'foo.items.0.bar', '123');
// newObj is now { foo: { items: [{ bar: '123' }] } }

Spec

Pointer aims to implement all the features from RFC6901 whilst also extending it to provide the following features:

1. Dot-delimited paths:

   get({ foo: { bar: { baz: 123 }}}, 'foo.bar.baz')
   // 123
   

2. Wildcard syntax to access array content:

   // Single level
   get({
       users: [
           { name: 'Joe' },
           { name: 'Jane' },
       ]
   }, 'users.*.name');
   // ['Joe', 'Jane']
   
   // Multiple levels
   get({
       items: [
           {
               tags: [{ value: 1 }, { value: 2 }],
           },
           {
               tags: [{ value: 3 }],
           },
       ]
   }, 'items.*.tags.*.value');
   // [ [ 1, 2 ], [ 3 ] ]
   

3. Push values into array:

   const obj = {};
   set(obj, '/items/-', 'foo');
   // { items: ['foo' ] }