object_mapper.js

var sys = require('util');

function value (obj, path) {
  var segments = path.split('/')
  if(segments[0] == '') segments = segments.slice(1)
  return segments.reduce(function (memo, segment) {
    return (typeof memo == 'object') ? memo[segment] : {}
  }, obj)
}

var ROOT_PATH = new RegExp('^\/')

function Mapper() {

}

Mapper.prototype.scope = function (path, func) {
  this.scopePath = path
  func.call(this)
  return this
}

Mapper.prototype.map = function (headerName, path, modifierFunc) {
  this.schema = this.schema || []
  var modifierFunc = modifierFunc || function (value) {return value}
  this.schema.push([headerName, path, modifierFunc])
  return this
}

Mapper.prototype.headers = function () {
  return this.schema.map(function (segs) {
    return segs[0]
  })
}

Mapper.prototype.eachRow = function (topEntity, func, thisArg) {
  var self = this

  var base = this.scopePath ? value(topEntity, this.scopePath) : topEntity

  if(!('forEach' in base)) base = [base]

  base.forEach(function (entity, idx) {
    var row = []
    this.schema.forEach(function (scheme) {
      var path = scheme[1],
          modifierFunc = scheme[2];
      if(ROOT_PATH.test(path)) { // look from top entity
        row.push(modifierFunc(value(topEntity, path)))
      } else { // look in this sub entity
        row.push(modifierFunc(value(entity, path)))
      }
    })
    thisArg = thisArg || row
    func.call(thisArg, row, idx + 1)
  }, this)

  return this
}

exports.define = function (definitions) {
  var constructor = function () {
    definitions.call(this)
  }
  sys.inherits(constructor, Mapper)
  return constructor
}

orders_mapper.js

var mapper = require('../lib/object_mapper');

function year (dateString) {
  return new Date(dateString).getFullYear()
}
function month (dateString) {
  return new Date(dateString).getMonth() + 1
}
function day (dateString) {
  return new Date(dateString).getUTCDate()
}
function address (props) {
  if(props == null) return ''
  return [props.street, props.street_2, props.postal_code].join(', ')
}
function tbd (value) {
  return 'TBD'
}

var OrderMapper = mapper.define(function () {

  this.scope('_embedded/line_items', function () {
    this
      .map('id',              '/id')
      .map('order',           '/code')
      .map('status',          '/status')
      .map('discount',        '/discount_total')
      .map('shipping price',  '/shipping_total')
      .map('net total',       '/net_total')
      .map('total',           '/total')
      .map('shipping zone',   '/shipping_description')
      .map('year',            '/updated_on', year)
      .map('month',           '/updated_on', month)
      .map('day',             '/updated_on', day)
      .map('payment method',  '/payment_info/name')
      .map('payment auth code',  '/payment_info/auth_code')
      .map('payment transaction ID',  '/payment_info/transaction_id')
      .map('name',            '/_embedded/contact/name')
      .map('email',           '/_embedded/contact/email')
      .map('address',         '/_embedded/address', address)
      .map('locality_name',   '/_embedded/address/locality_name')
      .map('region_name',     '/_embedded/address/region_name')
      .map('country_name',    '/_embedded/address/country_name')
      .map('product',         'product_title')
      .map('product_type_name','product_type_name')
      .map('variant',         'variant_title')
      .map('sku',             'variant_sku')
      .map('unit price',      'unit_price')
      .map('quantity',        'units')
      .map('requested quantity','requested_units')
      .map('order_weight_gr', '/total_weight_in_grams')
      .map('unit_weight_gr',  'product_weight_in_grams')
      .map('weight_gr',       'weight_in_grams')
  })

})

exports.OrderMapper = OrderMapper

orders_mapper_test.js

var assert = require("assert"),
    OrderMapper = require('../mappers/orders_mapper.js').OrderMapper;

describe('Orders mapper', function () {
  var mapper = new OrderMapper()

  describe('#headers()', function () {
    it('includes the following headers', function () {

      assert.deepEqual(
        mapper.headers(),
        [ 'id',
          'order',
          'status',
          'discount',
          'shipping price',
          'net total',
          'total',
          'shipping zone',
          'year',
          'month',
          'day',
          'payment method',
          'payment auth code',
          'payment transaction ID',
          'name',
          'email',
          'address',
          'locality_name',
          'region_name',
          'country_name',
          'product',
          'product_type_name',
          'variant',
          'sku',
          'unit price',
          'quantity',
          'requested quantity',
          'order_weight_gr',
          'unit_weight_gr',
          'weight_gr'
        ]
      )
    })
  })

  describe('#eachRow', function () {
    var order = {
      id: '123',
      code: 'abc',
      status: 'shipped',
      discount_total: 10,
      shipping_total: 11,
      shipping_description: 'London',
      net_total: 100,
      total_weight_in_grams: 120,
      total: 121,
      created_on: '2014-01-02',
      updated_on: '2014-01-03',
      payment_info: {
        type: 'webpay',
        name: 'Webpay',
        auth_code: '1234',
        transaction_id: 'abc'
      },
      _embedded: {
        contact: {
          name: 'Juan Perez',
          email: 'juan@perez.com'
        },
        address: {
          street: 'Main Street',
          street_2: 'flat B',
          postal_code: 'zip123',
          locality_name: 'London',
          region_name: 'Greater London',
          country_name: 'UK'
        },
        line_items: [
          {
            product_title: 'iPhone 17',
            product_type_name: 'A type',
            variant_title: 'white',
            variant_sku: 'sku123',
            unit_price: 10,
            units: 1,
            requested_units: 1,
            weight_in_grams: 100,
            product_weight_in_grams: 100
          },
          {
            product_title: 'iPhone 15',
            product_type_name: 'A type',
            variant_title: 'red',
            variant_sku: 'sku124',
            unit_price: 11,
            units: 2,
            requested_units: 3,
            weight_in_grams: 20,
            product_weight_in_grams: 10
          }
        ]
      }
    }

    it('maps API order to rows per order item', function () {
      var rows = []
      mapper.eachRow(order, function (r) {
        rows.push(r)
      })
      assert.equal(rows.length, 2)
      assert.deepEqual(rows[0], [
        '123',
        'abc',
        'shipped',
        10,
        11,
        100,
        121,
        'London',
        2014,
        1,
        3,
        'Webpay',
        '1234',
        'abc',
        'Juan Perez',
        'juan@perez.com',
        'Main Street, flat B, zip123',
        'London',
        'Greater London',
        'UK',
        'iPhone 17',
        'A type',
        'white',
        'sku123',
        10,
        1,
        1,
        120,
        100,
        100
      ])
      assert.deepEqual(rows[1], [
        '123',
        'abc',
        'shipped',
        10,
        11,
        100,
        121,
        'London',
        2014,
        1,
        3,
        'Webpay',
        '1234',
        'abc',
        'Juan Perez',
        'juan@perez.com',
        'Main Street, flat B, zip123',
        'London',
        'Greater London',
        'UK',
        'iPhone 15',
        'A type',
        'red',
        'sku124',
        11,
        2,
        3,
        120,
        10,
        20
      ])
    })
  })
})