simple-object-attribute-resolver

Simple Object Attribute Resolver - Resolves and returns the value from a Javascript object with simple path expression.

Frequently we need to traverse deep attribute path to extract some value from some object. This might require some defensive undefined object reference checking. JSON path might be too burdensome to use for simple use cases. This package aims to proivde simple yet reasonible exporession to access attribute values of an object.

Quick Examples

const soar = require('simple-object-attribute-resolver');

const data = {
  attr1: {
    attr11: {
      attr111: "Hello"
    }, attr1list1: [
      "value1"
      ,"value2"
      ,"value3"
    ]
  }, attr2: {

  }, list1: [
    [[1, 2, 3], [4, 5]]
  ], list2: [
    {
      hello: "World"
    }
  ]
};

soar.resolve(data, 'attr1.attr11.attr111'); // Hello
soar.resolve(data, 'attr1.attr1list1[1]'); // value2

const soarr1 = soar.resolver('attr1.attr11.attr111');
soarr1(data); // Hello

• See test directory for more examples

Install

Install from npm:

$ npm install simple-object-attribute-resolver

Methods

soar.isEmpty(data)

Convinent method that checks if data is empty. An empty data is null, undefined, array with length zero or object without any own property.

• params:
  • data - the data to check
• return:
  • true - if empty

soar.resolve(data, path)

Returns the value or reference to the element in the data object given by path.

• params:
  • data - the object to resolve the value from
  • path - simple dot path expression
• return:
  • the value of the element or the reference to the element in the data object.

soar.resolveArray(data, path)

Returns an array for the value or reference to the element in the data object given by path.

• params:
  • data - the object to resolve the value from
  • path - simple dot path expression
• return:
  • the value itself if it was an array or wrap the value in an array.

soar.resolver(path)

Returns the curried resolver function for the given path. It is useful to resolve the same attribute across different data object.

• params:
  • path - simple dot path expression
• return:
  • a resolver function for the given path which could resolve the attribute by passing data object.

soar.arrayResolver(path)

The resolver counter part of resolveArray.

• params:
  • path - simple dot path expression
• return:
  • a resolver function for the given path which could resolve the attribute as an Array by passing data object.

Notes

1. Be aware of the side effects. As the return value could be the reference to the elements in the data object, modifying the attribute of the reference could affect the source data (shallow copy).
2. This module is intented for quickly resolving a value from an input with the given path without having to worry about null, undefined or non-existing element along the path. If it is desired to find out which part of the path is causing undefined result, either print out both of the input and path to figure it out manually or just execute the actual de-referencing with proper Javascript syntax to cause an Error to be thrown.

License

MIT