post_searching.rb

# model
class Post
  include Neo4j::ActiveNode
  include Neo4j::Timestamps
  scope :published, -> { where(published: true) }
  
  def self.searching(search_params)
    result = Post.published
  
    # relations
    if search_params[:post_type].present?
      result = result.branch { post_type.where(id: search_params[:post_type]) }
    end
    if search_params[:post_class].present?
      result = result.branch { post_class.where(id: search_params[:post_class]) }
    end
    if search_params[:post_subject].present?
      result = result.branch { post_subject.where(id: search_params[:post_subject]) }
    end
  
    # bollean fields
    if search_params[:answered].present?
      result = result.where(answered: search_params[:answered].to_bool)
    end
    if search_params[:answerable].present?
      result = result.branch{ post_type.where(answerable: search_params[:answerable].to_bool) }
    end
  
    # text fields
    if search_params[:query].present?
      result = result.where("LOWER(n.title) =~ ? OR LOWER(n.body) =~ ?", ".*#{search_params[:query]}.*".downcase)
    end

    result
  end
end

# controller
module Api
  class PostsController < ApplicationController
    def index  
      @posts = Post.searching(search_params).page(@page).per(@per)
    end
  end
end