vendor/rails/actionpack/lib/action_view/helpers/debug_helper.rb

   1 module ActionView
   2   module Helpers
   3     # Provides a set of methods for making it easier to debug Rails objects.
   4     module DebugHelper
   5       # Returns a YAML representation of +object+ wrapped with <pre> and </pre>.
   6       # If the object cannot be converted to YAML using +to_yaml+, +inspect+ will be called instead.
   7       # Useful for inspecting an object at the time of rendering.
   8       #
   9       # ==== Example
  10       #
  11       #   @user = User.new({ :username => 'testing', :password => 'xyz', :age => 42}) %>
  12       #   debug(@user)
  13       #   # =>
  14       #   <pre class='debug_dump'>--- !ruby/object:User
  15       #   attributes:
  16       #   &nbsp; updated_at:
  17       #   &nbsp; username: testing
  18       #
  19       #   &nbsp; age: 42
  20       #   &nbsp; password: xyz
  21       #   &nbsp; created_at:
  22       #   attributes_cache: {}
  23       #
  24       #   new_record: true
  25       #   </pre>
  26
  27       def debug(object)
  28         begin
  29           Marshal::dump(object)
  30           "<pre class='debug_dump'>#{h(object.to_yaml).gsub("  ", "&nbsp; ")}</pre>"
  31         rescue Exception => e  # errors from Marshal or YAML
  32           # Object couldn't be dumped, perhaps because of singleton methods -- this is the fallback
  33           "<code class='debug_dump'>#{h(object.inspect)}</code>"
  34         end
  35       end
  36     end
  37   end
  38 end