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JSON P3

JSONPath, JSON Pointer and JSON Patch for JavaScript.

JSONPath (RFC 9535) is a mini language for selecting values from JSON-like data. A JSONPath query has the potential to return multiple values from a data structure, along with their locations. This implementation is non-evaluating and read-only.

JSON Pointer (RFC 6901) is a syntax for targeting a single value in JSON-like data. JSON Pointers can be resolved against data to retrieve the value, or used as part of a JSON Patch operation.

JSON Patch (RFC 6902) is a standard for describing update operations to perform on JSON-like data. You can apply a patch to add, remove, replace, copy and move values within a JSON document.

info

We use the term JSON-like data to describe arbitrary, possibly nested, JavaScript arrays and objects, plus primitive strings, numbers, booleans and null, as you might expect from JSON.parse(). When traversing JSON-like data, we only resolve an object's direct properties, and the length property of arrays and strings is ignored.

Install​

Node.js​

Install JSON P3 using your preferred project manager:

npm install --save json-p3

And import the module:

import { jsonpath } from "json-p3";

Example​

This example uses a JSONPath expression to find users with a "pending" status, then builds a JSON Patch to change those user's status to "active". Note that jsonpatch.apply() updates data in place.

import { jsonpath, jsonpatch } from "json-p3";

const query = "$.users[?@.status == 'pending'].status";

const data = {
  users: [
    { id: "usr_101", name: "Alice", status: "pending" },
    { id: "usr_102", name: "Bob", status: "active" },
    { id: "usr_103", name: "Charlie", status: "pending" },
  ],
};

const nodes = jsonpath.find(query, data);
const patchOps = nodes.map((node) => node.replaceOp("active"));

jsonpatch.apply(patchOps, data);
console.log(JSON.stringify(data, null, 2));
output
{
  "users": [
    {
      "id": "usr_101",
      "name": "Alice",
      "status": "active"
    },
    {
      "id": "usr_102",
      "name": "Bob",
      "status": "active"
    },
    {
      "id": "usr_103",
      "name": "Charlie",
      "status": "active"
    }
  ]
}