Rails hidden field undefined method 'merge' error
You should do:
<%= f.hidden_field :service, :value => "test" %>hidden_field expects a hash as a second argument
You are using a hidden_field instead of a hidden_field_tag. Because you are using the non-_tag version, it is assumed that your controller has already set the value for that attribute on the object that backs the form. For example:
controller:
def new ... @order.service = "test" ...end</pre>view:
<%= form_for @order do |f| %> <%= f.hidden_field :service %> <%= f.submit %><% end %>
It works fine in Ruby 1.9 & rails 4
<%= f.hidden_field :service, value: "test" %>