forms.rb

    form1 = Formotion::Form.new({
      sections: [{
        title: "Section 1",
        key: :section_one,
        select_one: true,
        rows: [{
          title: "First",
          key: :first,
          type: :check
        },
        {
          title: "Second",
          key: :second,
          type: :check,
          value: true
        }
      ]
    }

    ]})

primary_value.rb

def initialize(form, primary_key)
  ...
  @primary_value = @data_signal.map! do |data|
    lookup_title(@form, data, primary_key)
  end.replayLast
  ...
end

rac_form1.rb

class RACForm
  attr_reader :form, 
              :data_signal

  def initialize(form, primary_key, *secondary_keys)
    @form = form
    @data_signal = RACReplaySubject.replaySubjectWithCapacity RACReplaySubjectUnlimitedCapacity

    self.data_signal.sendNext @form.render

    @form.on_submit do |f|
      self.data_signal.sendNext @form.render
    end
  end
end

rac_form2.rb

  class RACForm
    attr_reader :form, 
                :data_signal, 
                :primary_value

    def initialize(form, primary_key, *secondary_keys)
      @form = form
      @data_signal = RACReplaySubject.replaySubjectWithCapacity RACReplaySubjectUnlimitedCapacity

      @primary_value = @data_signal.map! do |data|
        lookup_title(@form, data, primary_key)
      end.replayLast
      
      self.data_signal.sendNext @form.render

      @form.on_submit do |f|
        self.data_signal.sendNext @form.render
      end
    end

    private

    def lookup_title(form, data, key)
      row = form.row(key) || form.row(data[key])

      if row
        case row.type
        when :subform
          subform = row.subform.to_form
          return lookup_title(subform, subform.render, key)
        when :check
          return row.title
        else
          return row.value
        end
      end

      data[key]
    end
  end

rac_form3.rb

  class RACForm
    attr_reader :form, 
                :data_signal, 
                :data,
                :primary_value

    def initialize(form, primary_key, *secondary_keys)
      @form = form
      @data_signal = RACReplaySubject.replaySubjectWithCapacity RACReplaySubjectUnlimitedCapacity

      @primary_value = @data_signal.map! do |data|
        lookup_title(@form, data, primary_key)
      end.replayLast

      @secondary_values = @data_signal.map! do |data|
        secondary_keys.map { |k| lookup_title(@form, data, k) }
      end.replayLast

      self.data_signal.sendNext @form.render

      @form.on_submit do |f|
        self.data_signal.sendNext @form.render
      end
    end

    private

    attr_writer :data

    def update
      self.data = form.render
    end

    def lookup_title(form, data, key)
      row = form.row(key) || form.row(data[key])

      if row
        case row.type
        when :subform
          subform = row.subform.to_form
          return lookup_title(subform, subform.render, key)
        when :check
          return row.title
        else
          return row.value
        end
      end

      data[key]
    end
  end

secondary_values.rb

def initialize(form, primary_key, *secondary_keys)
  ...
  @secondary_values = @data_signal.map! do |data|
    secondary_keys.map { |k| lookup_title(@form, data, k) }
  end.replayLast
  ...
end

uitableviewcell.rb

class UITableViewCell
  def initWithForm(form)
    self.initWithStyle(UITableViewCellStyleSubtitle, reuseIdentifier: "IDENTIFIER") do
      rac.textLabel.text = form.primary_value
    end
  end
end

uitableviewcell2.rb

class UITableViewCell
  def initWithForm(form)
    self.initWithStyle(UITableViewCellStyleSubtitle, reuseIdentifier: "IDENTIFIER") do
      rac.textLabel.text = form.primary_value
      rac.detailTextLabel.text = form.secondary_values.map! do |x|
        x.join(", ")
      end
    end
  end
end

uiviewcontroller.rb

class FormViewController

  def initWithForms(forms)
    self.initWithNibName(nil, bundle: nil).tap do
      @forms = forms
      @composite_signal = RACSignal.combineLatest(@forms.map { |f| f.data_signal }).map! do |tuple|
        combined = {}
        tuple.allObjects.each do |x|
          combined.merge! flatten_values(x)
        end
        combined
      end  
    end
  end

  private
  
  def flatten_values(x)
    hash = {}
    x.each do |k,v|
      if v.is_a? Hash
        hash.merge! flatten_values(v)
      else
        hash.merge!({k => v})
      end
    end
    hash
  end
end

Line 4 isn’t correct Ruby syntax. In Ruby you call either super to call the super implementation of the current method or just the method to call a different one. I.e. in Ruby it is not possible to call the super implementation of a method other than the current method in the call stack.

(I’m not sure what the initWithNibName method in this case is –as you also pass it a block, which the normal objc implementation of initWithNibName knows nothing about– so unfortunately I cannot offer a correct version.)

Ooops. I intended to self.initWithNibName.tap. Fixed! Thanks!