CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3
Misha Moroshko
Misha Moroshko

Reputation: 171321

Ruby on Rails: Why my class extension is not recognized?

In views/products/list.html.erb I use:

<%= product.power.power_in_kw.to_kw if ... %>

to_kw is defined in lib/my_extensions.rb along with other methods:

class Symbol
  def pluralize
    to_s.pluralize.to_sym
  end
end

class BigDecimal
  def to_kw
    number_to_currency(self, :unit => "kw", :format => "%n%u", :precision => 1)
  end
end

class Float
  def to_dollar
    number_to_currency(self)
  end
end

config/environment.rb has the following line at the end:

require 'my_extensions'

However, I got the following error:

undefined method `to_kw' for #<BigDecimal:2704620,'0.555E2',8(8)>

What am I missing ?

Upvotes: 1

Views: 495

Answers (2)

Kevin
Kevin

Reputation: 1855

You should include ActionView::Helpers::NumberHelper in your BigDecimal and Float:

class BigDecimal
  include ActionView::Helpers::NumberHelper
  def to_kw
    number_to_currency(self, :unit => "kw", :format => "%n%u", :precision => 1)
  end
end

class Float
  include ActionView::Helpers::NumberHelper
  def to_dollar
    number_to_currency(self)
  end
end

I think the error undefined method to_kw is caused by the undefined method number_to_currency.

Upvotes: 1

Matchu
Matchu

Reputation: 85784

I know it's been hours since you submitted this, but these functions might work once you restart your app. Items in lib generally are not reloaded automatically like those in app, so changes made will not be reflected in the application until performing a full restart.

Just throwing it out there :)

I'm also going to point out that, once you have these methods up and running, they probably will not work immediately. This is because your views are defined in the context of all of the Rails view helpers, like ActionView::Helpers::NumberHelper, which defines number_to_currency. Your extension in lib, however, is not defined in such a context, and therefore cannot access those helpers.

ActionView::Helpers::NumberHelper.number_to_currency might be more likely to work as expected.

Upvotes: 2

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