wrong number of arguments (4 for 5) with Ruby 2 and Rails 4

Question

I've a problem with rails 4. I used this code with Rails 3. Now, i'm using the same with Rails 4 in another application and i got the message "wrong number of arguments (4 for 5) on the first line.

   <%= form_for :customer,
    :url => Braintree::TransparentRedirect.url,
    :params => @result && @result.params[:customer],
    :builder => ApplicationHelper::BraintreeFormBuilder,
    :errors => @result && @result.errors.for(:customer) do |f| %>
    <%= field_set_tag "Customer" do %>
    <dl>
        <dt><%= f.label :first_name, 'First Name' %></dt>
        <dd><%= f.text_field :first_name %></dd>
        <dt><%= f.label :last_name, 'Last Name' %></dt>
        <dd><%= f.text_field :last_name %></dd>
        <dt><%= f.label :phone, 'Phone' %></dt>
        <dd><%= f.text_field :phone %></dd>
    </dl>
    <% end %>
    <%= field_set_tag "Credit Card" do %>
    <% f.fields_for :credit_card do |cc| %>
    <dl>
        <dt><%= cc.label :number, 'Number' %></dt>
        <dd><%= cc.text_field :number %></dd>
        <dt><%= cc.label :expiration_date, 'Exipration Date (MM/YY)' %></dt>
        <dd><%= cc.text_field :expiration_date %></dd>
        <dt><%= cc.label :cvv, 'CVV' %></dt>
        <dd><%= cc.text_field :cvv %></dd>
    </dl>
    <% end %>
    <% end %>
    <%= hidden_field_tag :tr_data, @tr_data %>
    <%= f.submit 'Save Payment Info' %>
    <% end %>

EDIT : It seems the problem comes from "builder: ApplicationHelper::BraintreeFormBuilder,"

Please post a full stack trace (or even better, have a look at it yourself and check where you call the method producing the error and fix your call) — Holger Just, Nov 21 '13 at 14:25
Is Ruby 1.8 syntax still valid in Ruby 2.0? Try using ``url:`` instead of ``:url =>`` — John, Nov 21 '13 at 14:31
@John yes, of course hashrocket syntax is still valid. It doesn't seem to be an issue here. — Marek Lipka, Nov 21 '13 at 14:36
@john, i tried to use url:, params:, etc... It doesnt fix the problem — guilb, Nov 21 '13 at 14:39
It seems the problem comes from "builder: ApplicationHelper::BraintreeFormBuilder," — guilb, Nov 21 '13 at 14:41

score 4 · Answer 1 · answered Dec 16 '13 at 17:58

Just providing some additional information to corroborate the answer from @cschroed...

If you're like me, you've likely copied some example Braintree code into your app from here.

Rails 4 changed the call to the builder interface as @cschroed mentioned. All you need to do is update your local copy of the example code to match the new interface. For me this was as simple as changing

class BraintreeFormBuilder < ActionView::Helpers::FormBuilder
   ...
   def initialize(object_name, object, template, options, proc)

to

class BraintreeFormBuilder < ActionView::Helpers::FormBuilder
   ...
   def initialize(object_name, object, template, options)

score 2 · Accepted Answer · answered Nov 21 '13 at 14:44

I don't know anything about the BraintreeFormBuilder but I would check to see if ApplicationHelper::BraintreeFormBuilder is Rails 4 compatible and if you have installed the correct version. You are passing that as a :builder into form_for, but the way the builder is called from \action_view\helpers\form_helper.rb changed from Rails 3 to Rails 4. In Rails 3 it is:

builder.new(object_name, object, self, options, block)

In Rails 4 it is:

builder.new(object_name, object, self, options)

So if your version of ApplicationHelper::BraintreeFormBuilder is still expecting 5 arguments, but Rails 4 is now passing 4, you'd see an error like the one you have.

To narrow in on where an error like this is really occurring, you may have to view the Framework Trace rather than the Application Trace. If you are using a gem like better_errors this means clicking the "All Frames" option rather than just viewing the "Application Frames" when the error occurs.

wrong number of arguments (4 for 5) with Ruby 2 and Rails 4

2 Answers2