Class: Spree::ItemAdjustments

Inherits:
Object
  • Object
show all
Includes:
ActiveSupport::Callbacks
Defined in:
app/models/spree/item_adjustments.rb

Overview

Manage (recalculate) item (LineItem or Shipment) adjustments

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(item) ⇒ ItemAdjustments

Returns a new instance of ItemAdjustments.



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# File 'app/models/spree/item_adjustments.rb', line 10

def initialize(item)
  @item = item
  # Don't attempt to reload the item from the DB if it's not there
  @item.reload if @item.persisted?
end

Instance Attribute Details

#item ⇒ Object (readonly)

Returns the value of attribute item.



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# File 'app/models/spree/item_adjustments.rb', line 6

def item
  @item
end

Instance Method Details

#best_promotion_adjustment ⇒ Object 



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# File 'app/models/spree/item_adjustments.rb', line 74

def best_promotion_adjustment
  @best_promotion_adjustment ||= adjustments.promotion.eligible.reorder("amount ASC, created_at DESC").first
end

#choose_best_promotion_adjustment ⇒ Object

Picks one (and only one) promotion to be eligible for this order This promotion provides the most discount, and if two promotions have the same amount, then it will pick the latest one.



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# File 'app/models/spree/item_adjustments.rb', line 67

def choose_best_promotion_adjustment
  if best_promotion_adjustment
    other_promotions = self.adjustments.promotion.where("id NOT IN (?)", best_promotion_adjustment.id)
    other_promotions.update_all(:eligible => false)
  end
end

#update ⇒ Object 



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# File 'app/models/spree/item_adjustments.rb', line 16

def update
  update_adjustments if item.persisted?
  item
end

#update_adjustments ⇒ Object

TODO this should be probably the place to calculate proper item taxes values after promotions are applied



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# File 'app/models/spree/item_adjustments.rb', line 23

def update_adjustments
  # Promotion adjustments must be applied first, then tax adjustments.
  # This fits the criteria for VAT tax as outlined here:
  # http://www.hmrc.gov.uk/vat/managing/charging/discounts-etc.htm#1
  #
  # It also fits the criteria for sales tax as outlined here:
  # http://www.boe.ca.gov/formspubs/pub113/
  # 
  # Tax adjustments come in not one but *two* exciting flavours:
  # Included & additional

  # Included tax adjustments are those which are included in the price.
  # These ones should not effect the eventual total price.
  #
  # Additional tax adjustments are the opposite; effecting the final total.
  promo_total = 0
  run_callbacks :promo_adjustments do
    promotion_total = adjustments.promotion.reload.map(&:update!).compact.sum
    unless promotion_total == 0
      choose_best_promotion_adjustment
    end
    promo_total = best_promotion_adjustment.try(:amount).to_f
  end

  included_tax_total = 0
  additional_tax_total = 0
  run_callbacks :tax_adjustments do
    tax = (item.respond_to?(:all_adjustments) ? item.all_adjustments : item.adjustments).tax
    included_tax_total = tax.included.reload.map(&:update!).compact.sum
    additional_tax_total = tax.additional.reload.map(&:update!).compact.sum
  end

  item.update_columns(
    :promo_total => promo_total,
    :included_tax_total => included_tax_total,
    :additional_tax_total => additional_tax_total,
    :adjustment_total => promo_total + additional_tax_total,
    :updated_at => Time.now,
  )
end