implement snippets lifetime

app/helpers/snippets_helper.rb

 module SnippetsHelper
+  def snippet_lifetime_select_options
+    options = [
+        ['forever', nil],
+        ['1 day',   Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.day],
+        ['1 week',  Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.week],
+        ['1 month', Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.month]
+    ]
+    options_for_select(options)
+  end
 end

app/models/snippet.rb

@@ -33,6 +33,10 @@ class Snippet < ActiveRecord::Base
   def colorize
     system_colorize(content, file_name)
   end
+
+  def expired?
+    expires_at && expires_at < Time.current
+  end
 end
 # == Schema Information
 #

app/views/snippets/_form.html.haml

@@ -12,6 +12,9 @@
       %tr
         %td= f.label :file_name
         %td= f.text_field :file_name, :placeholder => "example.rb"
+      %tr
+        %td= f.label "Lifetime"
+        %td= f.select :expires_at, snippet_lifetime_select_options
       %tr
         %td{:colspan => 2}
           = f.label :content, "Code"

app/views/snippets/_snippet.html.haml

-%tr{ :id => dom_id(snippet), :class => "snippet", :url => project_snippet_path(@project, snippet) }
+- unless snippet.expired?
+  %tr{ :id => dom_id(snippet), :class => "snippet", :url => project_snippet_path(@project, snippet) }
     %td
       = image_tag gravatar_icon(snippet.author.email), :class => "left", :width => 40, :style => "padding:0 5px;"
       = truncate snippet.author.name, :lenght => 20

app/views/snippets/show.html.haml

-%h2
+- if !@snippet.expired?
+  %h2
     = "Snippet ##{@snippet.id} - #{@snippet.title}"
 
-.view_file
+  .view_file
     .view_file_header
       %strong
         = @snippet.file_name
@@ -10,13 +11,16 @@
       :erb
         <%= raw @snippet.colorize %>
 
-- if can?(current_user, :admin_snippet, @project) || @snippet.author == current_user
+  - if can?(current_user, :admin_snippet, @project) || @snippet.author == current_user
     = link_to 'Edit', edit_project_snippet_path(@project, @snippet), :class => "lbutton positive"
-- if can?(current_user, :admin_snippet, @project) || @snippet.author == current_user
+  - if can?(current_user, :admin_snippet, @project) || @snippet.author == current_user
     = link_to 'Destroy', [@project, @snippet], :confirm => 'Are you sure?', :method => :delete, :class => "lbutton delete-snippet negative", :id => "destroy_snippet_#{@snippet.id}"
-.clear
-%br
-.snippet_notes= render "notes/notes"
+  .clear
+  %br
+  .snippet_notes= render "notes/notes"
 
-.clear
+  .clear
 
+- else
+  %h2
+    Sorry, this snipped is no longer exists