Question

To manage errors in my address book app i initialize an array like this

err = Array.new

and then when i post something it checks if there are empty fields. If yes, for each empty field it adds a record in the array, and then redirect to /add page, like this

post '/' do
if params[:fname] == ""
    err.push "Insert a valid first name"
end
if params[:lname] == ""
    err.push "insert a valid last name"
end
if params[:phone] == ""
    err.push "insert a valid phone number"
end
if params[:mail] == ""
    err.push "insert a valid e-mail address"
end
if err.empty?
    c = Contatto.new
    c.fname = params[:fname]
    c.lname = params[:lname]
    c.phone = params[:phone]
    c.mail = params[:mail]
    c.save
    redirect '/'
else
    redirect '/add'
end
end

then the add page reads if the array has any record and if yes, cycles it to print each message

get '/add' do
  @err = err
  @title = 'Aggiungi'
  erb :aggiungi
end



<% if @err.any? %>
<div class="error">
    <% @err.each do |err| %>
        <%= err %><br>
    <% end %>
</div>
<% end %>

i think the error is that it re-initialize the array every time it changes from post ‘/’ to get ‘/add’ and so the result is an empty array…
How can i solve? thank you everyone!

Answer 1

If you want data for a specific visitor to persist between requests you need to be storing the error array in either a session or a cookie (session probably makes the most sense).

Luckily sessions in Sinatra are pretty easy: http://www.sinatrarb.com/intro#Using%20Sessions . Once enabled you can put pretty much anything you want into the session hash, so initializing with session[:errors] = [] and pushing with session[:errors] << "An error" should give you the persistence you are looking for.