Mapper

Stability: 2 - Stable

const Mapper = require('kado/lib/Mapper')

The Mapper library provides a functional interface for Object handling.

Class: Mapper

Mapper is a general-purpose Object handling toolkit. Some functions are static and may be used as shortcuts rather than creating a full instance.

static Mapper.getInstance (data)

• Options same as main constructor, below
• Returns: {Mapper} new instance of Mapper

Mapper.constructor (data)

• data {Object} optional data to populate
• Returns: {Mapper} new instance of Mapper

Instantiates a new empty Mapper instance, optionally populated with data

Mapper.map (iterator)

• iterator {Function} a method that takes value and key as arguments.
• Returns: {Mapper} the original object.

Example

const someObject = { foo: 'baz', two: 2, three: null }
Mapper.getInstance(someObject).map((value, key) => {
  if (value === null) value = ''
  return value
})

Mapper.merge (data)

• data {Object} optional data to populate
• Returns: {Mapper} the same as the called Mapper, for chaining

Mapper.get (key)

• key {mixed} path to requested data (see parseKey for valid types)
• Returns: {mixed} data from key location

Mapper.set (key, value)

• key {mixed} path to target (see parseKey for valid types)
• value {mixed} data to place at key location
• Returns: {mixed} the same value

Mapper.delete (key)

• key {mixed} path to delete (see parseKey for valid types)
• Returns: {string} deleted item name

Mapper.all ()

• Returns: {Object} all data contained within instance

Static (stateless) functions

static Mapper.mergeObject (base, overlay, depth, maxDepth)

• base {Object} target Object
• overlay {Object} source Object
• depth {number} (Default: 0) traversal control for nested items
• maxDepth {number} (Default: 50) traversal control for nested items
• Returns {Object} the base with overlay content merged as directed

static Mapper.getFromObject (base, keyArray)

• base {Object} target Object
• Returns: {mixed} data from key location

static Mapper.setToObject (base, keyArray, value)

• base {Object} target Object
• Returns {Object} the base with value set at path indicated by keyArray

static Mapper.deleteFromObject (base, keyArray, ctx = null)

• base {Object} target Object
• Returns {Object} the base with path indicated by keyArray deleted

static Mapper.parseKey (key)

• key {mixed} any form of locator, per type:
• {Array} already in key-array form; pass-through
• {string} path in dotted notation; will be split
• {function} function to call to obtain key
• Returns {Array} from least to most specific, used to traverse an Object