ruby - Sinatra and DataMapper Association -

i want make blog application in sinatra , datamapper, main application file this.

%w[rubygems sinatra data_mapper].each{ |r| require r }  datamapper.setup(:default , env['database_url'] || "sqlite3://#{dir.pwd}/development.db")  class post   include datamapper::resource    property :id,     serial   property :title,  string   property :author,  string   property :body,   text    has n, :comments end  class comment   include datamapper::resource    property :id,     serial   property :post_id,     serial   property :name,   string   property :body,   text    belongs_to :post end  helpers   def admin?     request.cookies[settings.username] == settings.token   end    def protected!     halt [401, 'not authorized'] unless admin?   end end   post '/comment/create'   comment = comment.new(:name => params[:name], :body => params[:body])   if comment.save     status 201     redirect '/post/'+post.id.to_s   else     status 412     redirect '/'   end end  '/post/:id'   @post = post.get(params[:id])   @comments = comment.new   erb :post end  delete '/comment/:id'   post.get(params[:id]).comment.(params[:id]).destroy   redirect '/post/'+post.id.to_s end  datamapper.auto_upgrade! 

now, problem how set instance variable of comments in post show file, make, delete, , show comments.

any suggestion , solutions welcomed.

if understand question, need. post.erb file like:

<h1><%= @post.title %></h1> <%= @post.body %>  <% @post.comments.each |comment| %>   <p><%= comment.name %><br /><%= comment.body %></p>    <form action="/comment/<%= comment.id %>" method="post">     <input type="hidden" name="_method" value="delete" />     <input type="submit" value="delete comment">   </form> <% end %> 

to create new comments, add post form right fields points /comments/create route.

the reason have form "delete" button in there because "delete '/comment/:id'" looking http delete method. unfortunately browsers don't implement that. looking "_method" field in post form how sinatra/rails/rack apps around that. then, near top of sinatra app, have tell "_method" field with:

use rack::methodoverride 

hopefully that's asking.