CODEWITHSUNDEEP
ruby-on-railscurrency
Damon Aw
Damon Aw

Reputation: 4792

Rails - Format number as currency format in the Getter

I am making a simple retail commerce solution, where there are prices in a few different models. These prices contribute to a total price. Imagine paying $0.30 more for selecting a topping for your yogurt.

When I set the price field to 

t.decimal   :price, precision:8, scale:2

The database stores 6.50 as 6.5. I know in the standard rails way, you call number_to_currency(price) to get the formatted value in the Views. I need to programmatically call the price field as well formatted string, i.e. $6.50 a few places that are not directly part of the View. Also, my needs are simple (no currency conversion etc), I prefer to have the price formatted universally in the model without repeated calling number_to_currency in views.

Is there a good way I can modify my getter for price such that it always returns two decimal place with a dollar sign, i.e. $6.50 when it's called?

Thanks in advance.

UPDATE

Thanks everyone.

I've elected to use Alex's approach because it seems very 'hackish' to do the includes just for formatting the number. Using his approach, I did:

  def price_change=(val)
      write_attribute :price_change, val.to_s.gsub(/[\$]/,'').to_d
  end

  def price_change
    "$%.2f" % self[:price_change]
  end

Cheers.

UPDATE 2

Caveat Emptor. Once you do this, you lose the ability to do operations to the number because it's now a string.

Please beware if anyone is facing the same problem as me.

Upvotes: 6

Views: 10390

Answers (4)

user1310699
user1310699

Reputation:

You can use the helpers module, but you should not include the whole module, because it includes a lot of methods which you may not really need or overrides some of yours. But you can use them directly:

ActionController::Base.helpers.number_to_currency(6.5)   
#=> "$6.50"

You could also define a method for the helpers, so you can easily use them. 

def helpers
  ActionController::Base.helpers
end

"#{helpers.number_to_currency(6.5)}"

Have a look at this railscast

Upvotes: 4

alex
alex

Reputation: 5002

Just add a method in your model which is named like your attribute in the database like:

def price
   "$%.2f" % self[:price]
end

which gives you full control over the formatting or use the Rails provided helper method

def price
   ActionController::Base.helpers.number_to_currency(self[:price])
end

this should do the trick. hope it helps!

Upvotes: 14

Vapire
Vapire

Reputation: 4578

I'd suggest going with a Presenter approach, like Draper (see this reailscast) does.

Another solution would be to implement your own method in your model, i.e. formatted_price and do the formatting on your own, (i.e. with the ActionView::Helpers::NumberHelper module). But since models represent the plain data in your rails application, it's kinda shady doing something like this and it interferes with the convention over configuration approach, I think.

Upvotes: 1

gayavat
gayavat

Reputation: 19398

try 

include ActionView::Helpers::NumberHelper

to your model

Upvotes: -1

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