routes.rb error - messes up view - rails 2.0

I have a simple RoR project where I have a table (Story) with stories
and links. I added a 3rd param in another table (permalink) and linked
it.

Now I want to access the records from Story using the permalink

In the console I can do the following:

s = Story.find_by_permalink("weblog")

=> #<Story id: 1, name: "my weblog", link: "http://mywelog.com",
created_at: "2008-01-06 02:25:36", updated_at: "2008-01-12 19:29:41",
permalink: "weblog">

this is the result I was expecting.

Now moving on to the controller, I have in there:

  def show
    @story = Story.find_by_permalink(params[:permalink])
  end

and in the view I have:

<p> My Story </p>
<h2><%= @story.name %></h2>
<p><%= link_to @story.link, @story.link %></p>

I also updated the routes.rb file, adding in there:
map.story 'story/show/:permalink', :controller => 'story', :action =>
'show'

Now when I run the server, and type in:
http://localhost:3000/story/show/weblog

I get the following error:

NoMethodError in Story#show

Showing story/show.rhtml where line #2 raised:

You have a nil object when you didn't expect it!
The error occurred while evaluating nil.name

Extracted source (around line #2):

1: <p> My Story </p>
2: <h2><%= @story.name %></h2>
3: <p><%= link_to @story.link, @story.link %></p>

RAILS_ROOT: /home/hkhan/digg
Application Trace | Framework Trace | Full Trace

app/views/story/show.rhtml:2:in
`_run_erb_47app47views47story47show46rhtml'

/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in
`send'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in
`compile_and_render_template'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:365:in
`render_template'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:316:in
`render_file'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1100:in
`render_for_file'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:836:in
`render_with_no_layout'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/layout.rb:262:in
`render_without_benchmark'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in
`render'
/usr/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in
`render'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1153:in
`default_render'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1159:in
`perform_action_without_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in
`call_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:689:in
`perform_action_without_benchmark'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in
`perform_action_without_rescue'
/usr/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in
`perform_action_without_rescue'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/rescue.rb:199:in
`perform_action_without_caching'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:678:in
`perform_action'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/query_cache.rb:33:in
`cache'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/query_cache.rb:8:in
`cache'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:677:in
`perform_action'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in
`send'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in
`process_without_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:685:in
`process_without_session_management_support'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/session_management.rb:123:in
`process'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:388:in
`process'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:171:in
`handle_request'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:115:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in
`dispatch_cgi'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:112:in
`handle_dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:78:in
`service'
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/local/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/local/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/local/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:82:in `start'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:62:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/servers/webrick.rb:66
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in
`new_constants_in'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/server.rb:39
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
script/server:3

app/views/story/show.rhtml:2:in
`_run_erb_47app47views47story47show46rhtml'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in
`send'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in
`compile_and_render_template'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:365:in
`render_template'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:316:in
`render_file'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1100:in
`render_for_file'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:836:in
`render_with_no_layout'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/layout.rb:262:in
`render_without_benchmark'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in
`render'
/usr/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in
`render'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1153:in
`default_render'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1159:in
`perform_action_without_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in
`call_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:689:in
`perform_action_without_benchmark'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in
`perform_action_without_rescue'
/usr/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in
`perform_action_without_rescue'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/rescue.rb:199:in
`perform_action_without_caching'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:678:in
`perform_action'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/query_cache.rb:33:in
`cache'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/query_cache.rb:8:in
`cache'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:677:in
`perform_action'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in
`send'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in
`process_without_filters'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:685:in
`process_without_session_management_support'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/session_management.rb:123:in
`process'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:388:in
`process'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:171:in
`handle_request'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:115:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in
`dispatch_cgi'
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:112:in
`handle_dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:78:in
`service'
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/local/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/local/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/local/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/local/lib/ruby/1.8/webrick/server.rb:82:in `start'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/webrick_server.rb:62:in
`dispatch'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/servers/webrick.rb:66
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in
`new_constants_in'
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in
`require'
/usr/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/server.rb:39
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
script/server:3

Request

Parameters:

{"id"=>"weblog"}

Show session dump

I also updated the routes.rb file, adding in there:
map.story 'story/show/:permalink', :controller => 'story', :action =>
'show'

Where did you add this line in the routes file? For it to take
priority over the route where the parameter is :id (ie the default
route, or what you get with map.resources) it needs to be higher up in
the file.

Fred

This could be if the new field :permalink is not populated in the
database yet!
find_by_permalink looks into the database, and finds a column of nil
records,
so controller sends a nil @story into the view.
The error is picked up in the view where it evaluates @story.name