The URL goes like this: http://localhost:3000/admin/photos?utf8=%E2%9C%93&tag=6

gistfile1.txt

URL goes like this:
http://localhost:3000/admin/photos?utf8=%E2%9C%93&tag=6

photos_helper.rb

module PhotosHelper
  def search_tag_form(options = nil)
		text   = text_field_tag :tag, params[:tag]
		submit = submit_tag "Search Tag", name: nil, class: "btn"

		form_tag tag_admin_photos_url, :class => "form-search", method: :get do
			concat content_tag(:div, text << submit)
		end
	end
end

routes.rb

Platafotto::Application.routes.draw do
  devise_for :admins
  devise_for :users

  namespace :admin do
		resources :admins
		resources :events
		resources :photos do
			get '(tags/:tag)', to: 'photos#index', as: :tag, on: :collection
		end
		resources :places
		resources :users
	end

	resources :events
	resources :photos do
			get '(tags/:tag)', to: 'photos#index', as: :tag, on: :collection
		end
	resources :places

  root 'static#home'
end