Question

Could not find the answer to the question on how to split forms in rails in multiple smaller forms.

Say you have a big form with

• firstname
• lastname
• gender
• age
• email
• country
• city
• state

I have a validate_presence for all these fields. So when I create several forms like:

= simple_form_for @profile, :wrapper => :inline do |f|

  = f.label "firstname"
  = f.select :firstname

without all the values from the top list (first name,last name,etc) I get errors because the splitter form does not contain those values and they need to be present at first to make this work at all.

What would be a good way to have several forms but with only a portion of the values and update them without getting the issue described above?

Answer 1

If you want the ability to update pieces of the model then you need to split the validations into pieces as well.

One way to do it is to have a virtual attribute in your model that gets set by a hidden field in each form. E.g you may have a form:

= simple_form_for @profile, :wrapper => :inline do |f|
  = f.hidden :form, :input_html => {:value => 'names'} 
  = f.label "firstname"
  = f.select :firstname

Then in your model:

class Profile
  attr_accessor :form

  validates :firstname, :presence => true, :if => lambda { |o| o.form == "names" }
end

The validation will run only if the change was submitted from the right form.

Check out conditional validation guide: http://guides.rubyonrails.org/active_record_validations_callbacks.html#conditional-validation for more details.

Other way is a multistep form as suggested by apneadiving: http://railscasts.com/episodes/217-multistep-forms This uses the same technique as in the first example by having a current_step attribute, but the progression is linear.