Custom inputs for Formtastic: CheckBoxesWithOtherInput and StringAsOtherInput

check_boxes_with_other_input.rb

# Assumes serialized attribute (can use ActiveRecord Store with Rails 3.2+)
# Splits attribute into hash with key for checkboxes (default 'checks')
# Use with TextFieldsWithOther to add 'other' key for text values ...
#
# symptoms[checks] <-- Array
# symptoms[other] <-- String
# 
# For a nested hash, define a top-level method (or with ActiveRecord::Store, define an accessor)
# In model ...
# class Patient < ActiveRecord::Base
# store :symptoms, accessors: [ 'attention', ... ]
# end
#
# Gives you access to ...
# <%= f.input 'attention', :as => :check_boxes_with_other, :collection => my_predefined_values %>
# attention[checks]
# <%= f.input 'attention', :as => :string_as_other %>
# attention[other]
# <%= f.input 'attention', :attr => 'age_of_onset', :as => :string_as_other %>
# attention[age_of_onset]

class CheckBoxesWithOtherInput < Formtastic::Inputs::CheckBoxesInput

  # Optional key to use for 'checks' hash; defaults to 'checks'
  def key_for_checked_hash
    options[:checked_key] || 'checks'
  end

  # Override CheckBoxesInput to add key_for_checked_hash subhash
  def input_name
    "#{object_name}[#{association_primary_key || method}][#{key_for_checked_hash}][]"
  end

  # Override CheckBoxesInput to add key_for_checked_hash subhash; returns an array
  def selected_values
    if object.respond_to?(method)
      checked_hash = object.send(method) || { key_for_checked_hash => [] }
      selected_items = [checked_hash[key_for_checked_hash]].compact.flatten
      [*selected_items.map { |o| send_or_call_or_object(value_method, o) }].compact
    else
      []
    end
  end
  
end

string_as_other_input.rb

# Assumes serialized attribute (can use ActiveRecord Store with Rails 3.2+)
# Works with CheckBoxesWithOtherInput to split attribute into hash with its own attr key (defaults to 'other') for text values ...
# symptoms[checks] <-- Array
# symptoms[other] <-- String
# 
# For a nested hash, define a top-level method (or with ActiveRecord::Store, define an accessor)
# In model ...
# class Patient < ActiveRecord::Base
# store :symptoms, accessors: [ 'attention', ... ]
# end
#
# Gives you access to ...
# <%= f.input 'attention', :as => :check_boxes_with_other, :collection => my_predefined_values %>
# attention[checks]
# <%= f.input 'attention', :as => :string_as_other %>
# attention[other]
# <%= f.input 'attention', :attr => 'age_of_onset', :as => :string_as_other %>
# attention[age_of_onset]

class StringAsOtherInput < Formtastic::Inputs::StringInput

  def attr_key
    options[:attr] || 'other'
  end

  # Overrides `input_html_options` to provide a `name` and `value` attribute.
  def input_html_options
    {
      :name => "#{object_name}[#{association_primary_key || method}][#{attr_key}]",
      :value => value
    }.merge(super)
  end

  # Returns a string
  def value
    if object.respond_to?(method)
      attr_hash = object.send(method) || { attr_key => '' }      
      val = attr_hash[attr_key]
    else
      ''
    end
  end

end