searchkick + elasticsearch issue

navbar.html.erb

<li class="navs">
		    	<%= form_tag posts_path, method: :get do%>
		    	<%=  text_field_tag :search, params[:query], placeholder: "Search Blog", name: "nil" , required: "", class: "input-field", id: "post_search", autocomplete: "off" do %>
		    		<%= submit_tag "", class: "material-icons search-box" %>
		    		<% end %>
		    		<% if params[:search].present? %>
		    			<%= link_to "X", posts_path %>
		    		<% end %>	
		    	
		    	<% end %>	
		    </li>

post.rb

class Post < ActiveRecord::Base
	searchkick autocomplete: ['title', 'description', 'tag_list']
	
	extend FriendlyId
	friendly_id :title, use: :slugged


	def should_generate_new_friendly_id?
		new_record? 
	end

	validates_presence_of :title, :description, :content, :tag_list, message: "can't be blank"
	acts_as_taggable
	belongs_to :user
	mount_uploader :preview, PreviewUploader

end

posts_controller.rb

class PostsController < ApplicationController
	before_action :find_post, only: [:show, :edit, :update, :destroy]
	before_action :authenticate_user!, except: [:index, :show]

	def new
		@post = current_user.posts.build
	end

	def create
		@post = current_user.posts.build(post_params)

		if @post.save
			redirect_to @post
		else
			render 'new'
		end
	end

	def edit
		@post = Post.friendly.find(params[:id])
	end

	def update
		@post = Post.friendly.find(params[:id])
		if @post.update(post_params)
			redirect_to @post
		else
			render 'edit'
		end
	end

	def destroy
		@post.destroy
		redirect_to root_path
	end

	def index
		if params[:tag]
			@posts = Post.tagged_with(params[:tag]).paginate(page: params[:page], per_page: 5)
		else
			@posts = Post.order('created_at DESC').paginate(page: params[:page], per_page: 2)
		end
		if params[:nil].present?
			@posts = Post.search(params[:nil]).paginate(page: params[:page])
		else
			@posts = Post.paginate(page: params[:page])
		end
	end

	def show
		@post = Post.friendly.find(params[:id])
	end

	def autocomplete
	    render json: Post.search(params[:query], autocomplete: true, limit: 5).map(&:title)
	end

	private

	def find_post
		@post = Post.friendly.find(params[:id])
	end

	def post_params
		params.require(:post).permit(:title, :description, :content, :tag_list, :preview)
	end


end