Removed duplication in views

tic_tac_toe_controller.rb

@@ -10,14 +10,19 @@ class TicTacToeController < Sinatra::Base
   end
 
   post '/setup' do
-    redirect to('/invalid_setup') if params[:player_mark] == nil || params[:opponent] == nil
-    session[:mark] = params[:player_mark]
-    session[:opponent] = params[:opponent]
-    redirect to('/game')
+    if params[:player_mark] || params[:opponent] == nil
+      session[:invalid_input_message] = "Please select an option to continue"
+      redirect to('/invalid_setup')
+    else
+      session[:mark] = params[:player_mark]
+      session[:opponent] = params[:opponent]
+      redirect to('/game')
+    end
   end
 
   get '/invalid_setup' do
-    erb :index_with_validation_messages
+    @invalid_input_message = session[:invalid_input_message]
+    erb :index
   end
 
   get '/game' do

views/index.erb

@@ -7,14 +7,22 @@
       <input type="radio" name="player_mark" value="O" />O
     </div>
 
+    <% if params[:player_mark] == nil %>
+      <p><%= @invalid_input_message %></p>
+    <% end %>
+
     <div class="form-section">
       Would you like to play against the computer?:
       <input type="radio" name="opponent" value="yes" />Yes
       <input type="radio" name="opponent" value="no" />No
     </div>
 
+    <% if params[:opponent] == nil %>
+      <p><%= @invalid_input_message %></p>
+    <% end %>
+
     <div class="form-section">
       <input id="setup-submit" type ="submit" value="Submit" />
     </div>
   </form>
-</div>
+</div>