wesrage / obex

JavaScript object wrapper providing useful extension methods

obex

Transform JavaScript objects.

• Map and filter objects as easily as arrays
• Methods can be chained by default
• 417 bytes gzipped

Installation

npm install --save obex
or
yarn add obex

Usage

var obex = require('obex');

var regularObject = { propertyName: 'value' };
var transformableObject = obex(regularObject);

An obex object is just like a regular JavaScript object, but it can be transformed using methods like filter and map to make object manipulation simpler. These methods can be chained together because obex adds non-enumerable properties to the given raw JavaScript object.

API

obex

obex(object)

• object: plain old JavaScript object to become transformable using obex methods.
  • Return: obex object

.filter

filter(testFunction)

• testFunction: function to test each key-value entry in the object.
  • Parameters: (key, value)
  • Return: true to keep the entry, false otherwise.

obex({ a: 3, b: 6 })
   .filter(function(key, value) {
      return value < 5;
   });
// { a : 3 }

.map

map(keyMapper, valueMapper)

• keyMapper: function to map old keys to new keys.
  • Parameters: (key [, value])
  • Return: replacement key for this entry.
• valueMapper: function to map old values to new values.
  • Parameters: (value [, key])
  • Return: replacement value for this entry.

obex({ a: 3, b: 6 }).map(
   function(key) {
      return key + key;
   },
   function(value) {
      return value * 2;
   }
);
// { aa: 6, bb: 12 }

.mapKeys

mapKeys(keyMapper)

• keyMapper: function to map old keys to new keys.
  • Parameters: (key [, value])
  • Return: replacement key for this entry.

obex({ a: 3, b: 6 }).mapKeys(function(key, value) {
   return key + key + value;
});
// { aa3: 3, bb6: 6 }

.mapValues

mapValues(valueMapper)

• valueMapper: function to map old values to new values.
  • Parameters: (value, [, key])
  • Return: replacement value for this entry.

function square(x) { return x * x };
obex({ a: 3, b: 6 }).mapValues(square);
// { a: 9, b: 36 }

.toArray

toArray(entryMapper)

• entryMapper: function to map key-value pairs to array elements,
  • Parameters: (key, value)
  • Return: array of elements mapped from key-value pairs

obex({ a: 1, b: 2 }).toArray(function(key, value) {
   return key + value;
});
// ['a1', 'b2']

.keys

keys()
Returns an array containing only the object's keys

obex({ a: 1, b: 2 }).keys();
// ['a', 'b']

.values

values()
Returns an array containing only the object's values

obex({ a: 1, b: 2 }).values();
// [1, 2]

.raw

raw()
Converts back to a plain old JavaScript object.

var a = obex({}).filter().map();
var b = a.raw();
var c = b.filter(); // Error