store rendered notes of todos in database to avoid costly rendering when you load a page

app/controllers/application_controller.rb

@@ -143,14 +143,6 @@ class ApplicationController < ActionController::Base
     return json_elems
   end
 
-  # Uses RedCloth to transform text using either Textile or Markdown Need to
-  # require redcloth above RedCloth 3.0 or greater is needed to use Markdown,
-  # otherwise it only handles Textile
-  #
-  def markdown(text)
-    RedCloth.new(text).to_html
-  end
-
   # Here's the concept behind this "mobile content negotiation" hack: In
   # addition to the main, AJAXy Web UI, Tracks has a lightweight low-feature
   # 'mobile' version designed to be suitablef or use from a phone or PDA. It

app/helpers/application_helper.rb

@@ -189,24 +189,6 @@ module ApplicationHelper
     end
   end
 
-  AUTO_LINK_MESSAGE_RE = %r{message://<[^>]+>} unless const_defined?(:AUTO_LINK_MESSAGE_RE)
-
-  # Converts message:// links to href. This URL scheme is used on Mac OS X
-  # to link to a mail message in Mail.app.
-  def auto_link_message(text)
-    text.gsub(AUTO_LINK_MESSAGE_RE) do
-      href = $&
-      left, right = $`, $'
-      # detect already linked URLs and URLs in the middle of a tag
-      if left =~ /<[^>]+$/ && right =~ /^[^>]*>/
-        # do not change string; URL is alreay linked
-        href
-      else
-        content = content_tag(:a, h(href), :href => h(href))
-      end
-    end
-  end
-
   def format_note(note)
     note = auto_link_message(note)
     note = markdown(note)

app/helpers/todos_helper.rb

@@ -64,7 +64,7 @@ module TodosHelper
 
   def collapsed_notes_image(todo)
     link = link_to(image_tag( 'blank.png', :width=>'16', :height=>'16', :border=>'0' ), "#", {:class => 'show_notes', :title => 'Show notes'})
-    notes = content_tag(:div, {:class => "todo_notes", :id => dom_id(todo, 'notes'), :style => "display:none"}) { format_note(todo.notes) }
+    notes = content_tag(:div, {:class => "todo_notes", :id => dom_id(todo, 'notes'), :style => "display:none"}) { todo.rendered_notes }
     return link+notes
   end
 

app/models/todo.rb

@@ -1,5 +1,6 @@
 class Todo < ActiveRecord::Base
 
+  before_save :render_note
   after_save :save_predecessors
 
   # associations
@@ -396,4 +397,12 @@ class Todo < ActiveRecord::Base
     return todo
   end
 
+  def render_note
+    unless notes.nil?
+      rendered_notes = Tracks::Utils.render_text(notes)
+    else
+      rendered_notes = nil
+    end
+  end
+  
 end

db/migrate/20120412072508_add_rendered_notes.rb

@@ -0,0 +1,26 @@
+class AddRenderedNotes < ActiveRecord::Migration
+  def self.up
+    add_column :todos, 'rendered_notes', :text
+    
+    puts "-- Clearing show_from dates from completed todos"
+    # clear up completed todos that have show_from set. These could have been left over from before the AASM migration
+    Todo.completed.find(:all, :conditions =>[ "NOT(show_from IS NULL)"]).each {|t| t.show_from=nil; t.save!}
+    puts "-- Generating new column values from notes. This may take a while."
+    # Call save! on each todo to force generation of rendered_todos
+    i=0; max = Todo.all.count; start = Time.now
+    Todo.all.each do |todo|
+      todo.save(false)
+      i = i + 1
+      if i%250==0
+        elapsed_sec = (Time.now-start)
+        remaining = (elapsed_sec / i)*(max-i)
+        puts "Progress: #{i} / #{max} (#{(i.to_f/max.to_f*100.0).floor}%) ETA=#{remaining.floor}s"
+      end
+    end
+    puts "Done: #{i} / #{max}"
+  end
+
+  def self.down
+    remove_column :todos, 'rendered_notes'
+  end
+end

lib/tracks/utils.rb

@@ -0,0 +1,45 @@
+module Tracks
+
+  class Utils
+    AUTO_LINK_MESSAGE_RE = %r{message://<[^>]+>} unless const_defined?(:AUTO_LINK_MESSAGE_RE)
+  
+    # Converts message:// links to href. This URL scheme is used on Mac OS X
+    # to link to a mail message in Mail.app.
+    def self.auto_link_message(text)
+      text.gsub(AUTO_LINK_MESSAGE_RE) do
+        href = $&
+        left, right = $`, $'
+        # detect already linked URLs and URLs in the middle of a tag
+        if left =~ /<[^>]+$/ && right =~ /^[^>]*>/
+          # do not change string; URL is alreay linked
+          href
+        else
+          content = content_tag(:a, h(href), :href => h(href))
+        end
+      end
+    end
+
+    def self.render_text(text)
+      rendered = Tracks::Utils.auto_link_message(text)
+      rendered = markdown(rendered)
+      rendered = ActionController::Base.helpers.auto_link(rendered, :link => :urls)
+
+      # add onenote and message protocols
+      Sanitize::Config::RELAXED[:protocols]['a']['href'] << 'onenote'
+      Sanitize::Config::RELAXED[:protocols]['a']['href'] << 'message'
+  
+      rendered = Sanitize.clean(rendered, Sanitize::Config::RELAXED)
+      return rendered
+    end
+    
+    # Uses RedCloth to transform text using either Textile or Markdown Need to
+    # require redcloth above RedCloth 3.0 or greater is needed to use Markdown,
+    # otherwise it only handles Textile
+    #
+    def self.markdown(text)
+      RedCloth.new(text).to_html
+    end
+
+  end
+  
+end