WALKTHROUGH: Creating new shipment from admin panel

gistfile1.txt

# api/app/controllers/spree/api/shipments_controller.rb
def create
  variant = Spree::Variant.find(params[:variant_id])
  quantity = params[:quantity].to_i
  @shipment = @order.shipments.create(:stock_location_id => params[:stock_location_id])
  @order.contents.add(variant, quantity, nil, @shipment)

  @shipment.refresh_rates
  @shipment.save!

  respond_with(@shipment.reload, :default_template => :show)
end

# core/app/models/spree/order_contents.rb
def add(variant, quantity=1, currency=nil, shipment=nil)
  line_item = order.find_line_item_by_variant(variant)
  add_to_line_item(line_item, variant, quantity, currency, shipment)
end

# core/app/models/spree/order_contents.rb
def add_to_line_item(line_item, variant, quantity, currency=nil, shipment=nil)
  if line_item
    line_item.target_shipment = shipment
    line_item.quantity += quantity.to_i
    line_item.currency = currency unless currency.nil?
    line_item.save
  else
    line_item = LineItem.new(quantity: quantity)
    line_item.target_shipment = shipment
    line_item.variant = variant
    if currency
      line_item.currency = currency unless currency.nil?
      line_item.price    = variant.price_in(currency).amount
    else
      line_item.price    = variant.price
    end
    order.line_items << line_item
    line_item
  end

  order.reload
  line_item
end

# core/app/models/spree/line_item.rb
def update_inventory
  if changed?
    Spree::OrderInventory.new(self.order).verify(self, target_shipment)
  end
end

# core/app/models/spree/order_inventory.rb
def verify(line_item, shipment = nil)
  if order.completed? || shipment.present?

    variant_units = inventory_units_for(line_item.variant)

    if variant_units.size < line_item.quantity
      quantity = line_item.quantity - variant_units.size

      shipment = determine_target_shipment(line_item.variant) unless shipment
      add_to_shipment(shipment, line_item.variant, quantity)
    elsif variant_units.size > line_item.quantity
      remove(line_item, variant_units, shipment)
    end
  else
    true
  end
end

# core/app/models/spree/order_inventory.rb
def add_to_shipment(shipment, variant, quantity)
  if variant.should_track_inventory?
    on_hand, back_order = shipment.stock_location.fill_status(variant, quantity)

    on_hand.times { shipment.set_up_inventory('on_hand', variant, order) }
    back_order.times { shipment.set_up_inventory('backordered', variant, order) }
  else
    quantity.times { shipment.set_up_inventory('on_hand', variant, order) }
  end

  # adding to this shipment, and removing from stock_location
  if order.completed?
    shipment.stock_location.unstock(variant, quantity, shipment)
  end

  quantity
end