Rails | Same column multiple times in form | has_many through

Question

I have a multi-step form that creates a Post and its Topics.

class Post < ActiveRecord::Base
  has_many :post_topics
  has_many :topics, through: :post_topics
end

class Topic < ActiveRecord::Base
  has_many :post_topics
  has_many :posts, through: :post_topics
  belongs_to :parent, class_name: 'Topic'
  has_many :subtopics, class_name: 'Topic', foreign_key: 'parent_id'

  scope :subtopics, lambda { where.not(parent_id: nil) }
  scope :topics, lambda { where(parent_id: nil) }
end

class PostTopic < ActiveRecord::Base
  belongs_to :post
  belongs_to :topic
end

Topic class has a self-referential association. I have a column parent_id in Topics table. The ones with parent_id: nil are the root topics and the ones with a parent_id value are subtopics.

This is the form.

<%= simple_form_for(@post, method: :put, url: wizard_path) do |f| %>
 <%= f.error_notification %>

 <%= f.input :name, required: true, autofocus: true %>
 <%= f.input :description, required: true %>
 <%#= f.select :topic_ids, Topic.topics.collect {|x| [x.name, x.id]}, {}, label: "Select Topic" %>  
 <%= f.select :topic_ids, Topic.subtopics.collect {|x| [x.name, x.id]}, {}, :multiple => true, class: "multipleSelect", label: "Select Subtopic" %>
 <%= f.button :submit, "NEXT", class: 'btn btn-danger' %>

<% end %>

The form looks like this

Name
Description
Select SubTopics

Name, Description and Select Subtopics fields save values as expected. What I want is another select input that lets users select a Topic (parent topic) (commented out that line in the above form)

Name
Description
Select Topic
Select SubTopics

How do I keep the same column(topic_ids) multiple times in this form so that

"Select Topic" input will save the parent topic
"Select Subtopics" input will save multiple subtopics

Rails | Same column multiple times in form | has_many through

0 Answers0