Object Query Library

What is it

OQL is small library without dependencies that applies specified changes to nested object like Redux store and returns new object keeps source object unchanged.

Main concepts

OQL recieves two params: Single query or array of queries as first parameter and source object which will be used for new object as second one.

result = oql(["set first", { second: 1}], { first: 0});

result will be {first: { second: 1}}

or

result = oql(
  [
    ["set first", { second: 1}],
    ["set first.second", 2]
  ],
  { first: 0});

result will be {first: { second: 2}}

Query

Queries are used for describing what OQL have to do with source object.

Query consists of 2 parts: command and data and pass to OQL as array [command, data].

The command string consists of method and path with space delimiter "set first.second.id=1

The method defines how the data changes will be applied to the source object.

The path is used to specify the point in the object where the changes will be applied.

Path examples

"first" choose property first in object { first: 1}

"first.second.third" choose property third in object { first: { second: { third: 3}}}

"0" choose first element of array or property 0 in object

"-1" choose last (first from the end) element of array

"id=1" choose element with property id equals 1 in array of objects [{ id: 1}, { id: 2}]

These approaches of choosing properties and elements can be combined to access any point in object.

Method

Set - replace data in the point chosen by path with new data.

Add - merge data in the point chosen by path with new data.

Del - delete array or object element in the point chosen by path.

Install

npm install -S oql-lib

Usage

import { oql } from 'oql-lib';

Set property of object

result = oql(["set first.second", 2], { first: { second: 0}})

result will be { first: { second: 2}}

History of changes

v1.1.0 - implemented set method

v1.2.0 - implemented add method

v1.2.1 - fix bundle

v1.3.0 - implemented del method

v1.3.1 - refactoring. 100% test coverage