Text reverse, palindrome, concatenation in sinatra

gistfile1.rb

# Main file string_reverse.rb


require 'sinatra'

helpers do
  def concatenate_strings(string1, string2)
    string1 + string2
  end

  def is_a_palindrome?(string1, string2)
    string1==string2
  end
end

get '/' do
  erb :home
end

post '/reverse' do
  erb :show
end

# View files: views/home.erb

<h1>String Reverse</h1>
<p>The String reverse Service will accept a string from you
    and return you the reversed string. Have fun!</p>
<form action="/reverse" method="post" accept-charset="utf-8">
    <input type="text" name="str" value="Type a string..." id="str">
    <input type="submit" value="... and reverse it!">
</form>


# View file: views/show.erb

h1>String Reverse results</h1>
<% initial_string = params[:str] %>
<% result_string = initial_string.reverse %>
<% concatenated_strings = concatenate_strings(initial_string, result_string) %>
<% palindrome_string = is_a_palindrome?(result_string, initial_string ) %>
<p>You had entered the string - <%= initial_string %></p>
<p>The reversed string is     - <%= result_string %></p>
<p>The concatenation of the two strings is : <%= concatenated_strings %></p>
<p><%= result_string %> is <% if !(palindrome_string) %> not <% end %> a palindrome of <%= initial_string%></p>
<p>Click <a href="/">here</a> to try a new string.</p>

# Note: Probably a better way than putting all initialization in view