# Validates\_presence\_of generates syntax error

**URL:** <https://www.ruby-forum.com/t/validates-presence-of-generates-syntax-error/83654>\
**Category:** Ruby\
**Created:** [January 28, 2007, 1:36pm UTC](https://www.ruby-forum.com/t/validates-presence-of-generates-syntax-error/83654 "2007-01-28T13:36:00Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![libsfan01](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/779978/32.png) [@libsfan01](https://www.ruby-forum.com/u/libsfan01)\
**Post date:** [January 28, 2007, 1:36pm UTC](https://www.ruby-forum.com/t/validates-presence-of-generates-syntax-error/83654/1 "2007-01-28T13:36:00Z")

</div>

hi all

im following the tutorial in the book “agile development with rails”  
as soon as i get to the point where u first add rails generated  
validation i get a syntax error every time:

app/models/product.rb:1: syntax error  
class Product \< ActiveRecord::Base  
validates\_presence\_of :title, :description, :image\_url  
end

what ive done is added:

“validates\_presence\_of :title, :description, :image\_url”

to:

“class Product \< ActiveRecord::Base  
end”

to get:

“class Product \< ActiveRecord::Base  
validates\_presence\_of :title, :description, :image\_url  
end”

which immediately generates a syntax error in “[http://localhost:3000/](http://localhost:3000/)  
admin”

when i then remove the line to return the page to its original state,  
i get another syntax error?

as shown here (PLEASE HELP!!):

"  
SyntaxError in AdminController#index

app/models/product.rb:1: syntax error  
class Product \< ActiveRecord::Base  
end

RAILS\_ROOT: script/…/config/…  
Application Trace | Framework Trace | Full Trace

/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:204:in `load_without_new_constant_marking' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:204:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:203:in `new_constants_in' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:203:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:95:in `require_or_load' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:249:in `load\_missing\_constant’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:453:in `const_missing' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:465:in `const\_missing’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `module_eval' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ inflector.rb:251:in `module\_eval’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `constantize' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ core_ext/string/inflections.rb:148:in `constantize’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
pagination.rb:195:in `paginator_and_collection_for' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ pagination.rb:130:in `paginate’  
app/controllers/admin\_controller.rb:12:in `list' app/controllers/admin_controller.rb:3:in `index’

/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:204:in `load_without_new_constant_marking' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:204:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:203:in `new_constants_in' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:203:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:95:in `require_or_load' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:249:in `load\_missing\_constant’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:453:in `const_missing' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:465:in `const\_missing’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `module_eval' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ inflector.rb:251:in `module\_eval’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `constantize' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ core_ext/string/inflections.rb:148:in `constantize’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
pagination.rb:195:in `paginator_and_collection_for' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ pagination.rb:130:in `paginate’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
base.rb:1095:in `send' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:1095:in `perform\_action\_without\_filters’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
filters.rb:632:in `call_filter' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ filters.rb:634:in `call\_filter’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
filters.rb:619:in `perform_action_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ benchmarking.rb:66:in `perform\_action\_without\_rescue’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
benchmarking.rb:66:in `measure' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ benchmarking.rb:66:in `perform\_action\_without\_rescue’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
rescue.rb:83:in `perform_action' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:430:in `send’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
base.rb:430:in `process_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ filters.rb:624:in `process\_without\_session\_management\_support’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
session\_management.rb:114:in `process' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:330:in `process’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/dispatcher.rb:41:in  
`dispatch' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick_server.rb:113:in `handle\_dispatch’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick\_server.rb:79:in  
`service' /usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service’  
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /usr/lib/ruby/1.8/webrick/server.rb:155:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:144:in `start' /usr/lib/ruby/1.8/webrick/server.rb:144:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:94:in `start' /usr/lib/ruby/1.8/webrick/server.rb:89:in `each’  
/usr/lib/ruby/1.8/webrick/server.rb:89:in `start' /usr/lib/ruby/1.8/webrick/server.rb:79:in `start’  
/usr/lib/ruby/1.8/webrick/server.rb:79:in `start' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick_server.rb:63:in `dispatch’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/commands/servers/  
webrick.rb:59  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in  
`gem_original_require' /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `require' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `new\_constants\_in’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `require' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/commands/server.rb:39 /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem\_original\_require’  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in `require' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `require’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `new_constants_in' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `require’  
script/server:3

/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:204:in `load_without_new_constant_marking' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:204:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:203:in `new_constants_in' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:203:in `load\_file’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:95:in `require_or_load' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:249:in `load\_missing\_constant’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:453:in `const_missing' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:465:in `const\_missing’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `module_eval' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ inflector.rb:251:in `module\_eval’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
inflector.rb:251:in `constantize' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ core_ext/string/inflections.rb:148:in `constantize’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
pagination.rb:195:in `paginator_and_collection_for' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ pagination.rb:130:in `paginate’  
app/controllers/admin\_controller.rb:12:in `list' app/controllers/admin_controller.rb:3:in `index’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
base.rb:1095:in `send' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:1095:in `perform\_action\_without\_filters’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
filters.rb:632:in `call_filter' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ filters.rb:634:in `call\_filter’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
filters.rb:619:in `perform_action_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ benchmarking.rb:66:in `perform\_action\_without\_rescue’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
benchmarking.rb:66:in `measure' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ benchmarking.rb:66:in `perform\_action\_without\_rescue’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
rescue.rb:83:in `perform_action' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:430:in `send’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
base.rb:430:in `process_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ filters.rb:624:in `process\_without\_session\_management\_support’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action\_controller/  
session\_management.rb:114:in `process' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.1/lib/action_controller/ base.rb:330:in `process’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/dispatcher.rb:41:in  
`dispatch' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick_server.rb:113:in `handle\_dispatch’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick\_server.rb:79:in  
`service' /usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service’  
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /usr/lib/ruby/1.8/webrick/server.rb:155:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:144:in `start' /usr/lib/ruby/1.8/webrick/server.rb:144:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:94:in `start' /usr/lib/ruby/1.8/webrick/server.rb:89:in `each’  
/usr/lib/ruby/1.8/webrick/server.rb:89:in `start' /usr/lib/ruby/1.8/webrick/server.rb:79:in `start’  
/usr/lib/ruby/1.8/webrick/server.rb:79:in `start' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/webrick_server.rb:63:in `dispatch’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/commands/servers/  
webrick.rb:59  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in  
`gem_original_require' /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `require' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `new\_constants\_in’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `require' /usr/lib/ruby/gems/1.8/gems/rails-1.2.1/lib/commands/server.rb:39 /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem\_original\_require’  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in `require' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `require’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active\_support/  
dependencies.rb:496:in `new_constants_in' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.0/lib/active_support/ dependencies.rb:496:in `require’  
script/server:3

Request

Parameters: None

Show session dump

* * *

flash: !ruby/hash:ActionController::Flash::FlashHash {}

Response  
Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}"

PLEASE HELP!!