CODEWITHSUNDEEP
ruby-on-railsrubymodelsum
user2142645
user2142645

Reputation: 69

Model rails calculate total price

I am trying to calculate a total sum from an array of ids. It works fine when I select only one Servicio but in an array it shows me this message:

    undefined method `+' for #<Servicio:0x9c14c5c>

Extracted source (around line #91):

88:         </div>
89:         <div class="large-3 columns">
90:           <strong><%= model_class.human_attribute_name(:total) %>:</strong></dt>
91:           <%= @recibo.total %>
92:         </div>
93:       </div>
94:     </div>

This is my model Recibo

class Recibo < ActiveRecord::Base
  attr_accessible :cajero, 
  :doctor_id, 
  :numero_recibo, 
  :paciente_id, 
  :total,
  :servicio_ids

  belongs_to :doctor
  belongs_to :paciente
  has_many :atencions
  has_many :servicios, :through => :atencions

  def total
    servicio_by_id = Servicio.find(servicio_ids)
    total = servicio_by_id.sum.precio
  end
end

Thanks!

Upvotes: 2

Views: 843

Answers (1)

Carlos Ramirez III
Carlos Ramirez III

Reputation: 7434

You need to specify which attribute of the Servicio should be used by the sum method since the Servicio class does not implement the + method itself.

Try this

total = servicio_by_id.sum(&:precio)

This will add up the value of each Servicio's precio attribute.

Upvotes: 3

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