Rails4 has_many：通过那时如何获取new.html.erb

Question

我使用Rails4.2.8，Ruby2.5.0。

我在questions，classifies，tags中有多级关系，表关系是这样的：

我的模特：

class Question < ActiveRecord::Base
  has_many :taggables,:dependent => :destroy, inverse_of: :question
  has_many :tags, through: :taggables, :dependent => :destroy
  belongs_to :classify
  belongs_to :user
  accepts_nested_attributes_for :tags
  accepts_nested_attributes_for :taggables
end

class Tag < ActiveRecord::Base
  has_many :taggables, :dependent => :destroy,inverse_of: :question
  has_many :questions, through: :taggables, :dependent => :destroy,inverse_of: :question
  belongs_to :classify
end

class Classify < ActiveRecord::Base
  has_many :questions, :dependent => :destroy, inverse_of: :classify
  has_many :tags, :dependent => :destroy, inverse_of: :classify
  accepts_nested_attributes_for :questions
  accepts_nested_attributes_for :tags
end

class Taggable < ActiveRecord::Base
  belongs_to :question
  belongs_to :tag
  accepts_nested_attributes_for :question
end

我的dbs：

class CreateQuestions < ActiveRecord::Migration
      def change
        create_table :questions do |t|
          t.string :title
          t.text :content
          t.integer :classify_id
          t.timestamps
        end
      end
    end

class CreateTags < ActiveRecord::Migration
      def change
        create_table :tags do |t|
          t.string :name
          t.text :content
          t.integer :classify_id
          t.timestamps
        end
      end
    end


class CreateClassifies < ActiveRecord::Migration
  def change
    create_table :classifies do |t|
      t.string :name
      t.text :content
      t.timestamps
    end
  end
end

class CreateTaggables < ActiveRecord::Migration
  def change
    create_table :taggables do |t|
      t.integer :question_id
      t.integer :tag_id
      t.timestamps
    end
  end
end

我的控制器：

questions_controller.rb
def new
    @question = Question.new
    @question.taggables.build
    @question.tags.build
  end



classifies_controller.rb
def new
    @classify = Classify.new
    @classify.questions.build
    @classify.tags.build
  end


tags_controller.rb
def new
    @tag = Tag.new
    @tag.taggables.build
    @tag.questions.build
  end

我的questions/new.html.erb

    <%= form_for(@question) do |f| %>
    <div class="form-group">
        <%= f.label :classify, "Classify and Tags" %><br>
        <div class="input-group tags" >
          <div class="tags_select">
            <%= f.select :classify_id, Classify.all.collect { |c| [c.name, c.id]},{}, class: "form-control" %>   ##I can get the classify_id in questions 
          </div>
          <div class="tags_input col-md-12">
            <%= f.text_field :tag, class: "",multiple:"multiple",placeholder: "Please input the tags" %> 
**## There how can I get the input tags , and record the id and name in `tags table` ,  `taggables table`? Then how can I show the tags name in the question `show.html.erb`?**
          </div>
        </div>
      </div>

    <% end %>

我想要的是如何在tags table，taggables table中记录输入标签ID和名称，那么如何在问题show.html.erb中显示标签名称？

Thansk非常感谢你的帮助。