crud in sinatra

sinatracrud.rb

#here is app.rb:
  get '/admin' do
			protected!
			@posters = Poster.all
			@category_1_posters = @posters.all :category => 1
			@category_2_posters = @posters.all :category => 2
			@category_3_posters = @posters.all :category => 3
      haml :'admin/index'
    end


		get '/admin/add' do
			protected!
			haml :'admin/add'
		end

		post '/admin/add' do
			protected!
			p = Poster.new params['poster']
			tempfile = params['file'][:tempfile]
			filename = params['file'][:filename]
			directory = "public/posters"
			path = File.join('public', 'posters', filename)
			File.open(path, "wb") { |f| f.write(tempfile.read) }

			p.image = filename	
			p.save
			flash[:notice] = 'Poster was added successfully.'
			redirect '/admin#top'
		end

		delete '/admin/delete/' do
			protected!
			poster = Poster.get(params[:poster])
			poster.destroy
			flash[:notice] = 'Poster was destroyed'
			redirect '/admin#top'
		end

	end


# This is the model
class Poster
  include DataMapper::Resource
  
	property :id, Serial
	property :image, String, :required => true
  property :artist_name, String, :required => true
	property :teacher, String, :required => true
	property :school, String, :required => true
	property :category, Integer, :required => true
	property :votes_count, Integer

	has n, :votes

	def image_path
		File.join File::SEPARATOR, "posters", self.image
	end
end

views.html.haml

-#admin/add.haml
%br
#vote-form
	%form{ :action => '/admin/add', :method => 'post',:enctype => "multipart/form-data" }	
		%label{ :for =>  'file' } Poster Image
		%input{ :type => 'file', :name => "file", :id => 'file' }
		%br
		%label{ :for =>  'artist_name' } Artist's Name
		%input{ :type => 'text', :name => "[poster][artist_name]", id => 'artist_name' }
		%br
		%label{ :for =>  'school' } School
		%input{ :type => 'text', :name => "[poster][school]", id => 'school' }
		%br
		%label{ :for =>  'teacher' } Teacher
		%input{ :type => 'text', :name => "[poster][teacher]", id => 'teacher' }
		%br
		%label{ :for =>  'category' } Category
		%select{ :name => "[poster][category]", id => 'category' }
			%option{ :value => 1 } k-2 grades
			%option{ :value => 2 } 3-4 grades
			%option{ :value => 3 } 5-6 grades
		%br
		%input{ :type => 'submit', :value => 'add new poster'}
-#admin/index.haml
%br
%h1 ADMIN SECTION
%a{ :href => '/admin/add'	 } 
	%h2 Add A New Poster
#vote-form
	#error-container
		%a{:name=>'top'}
		= flash[:notice]
	.poster-list#category_1
		%h3 K-2 grades
		= haml :'admin/poster', :locals => {:posters => @category_1_posters}
	.clear
	.poster-list#category_2
		%h3 3-4 grades
		= haml :'admin/poster', :locals => {:posters => @category_2_posters}
	.clear
	.poster-list#category_3
		%h3 5-6 grades
		= haml :'admin/poster', :locals => {:posters => @category_3_posters}
	.clear

thanks bro!