ruby

Using validates_presence_of on a boolean field? Should use validates_inclusion_of!

Theo, 3 Comments

rsvp.theoandpat.com had boolean flag to marked whether or not a visitor was going to be able to make it to our wedding. Unfortunately, if you selected you were not able to make it and submit the form, the application would return saying it could not process your submission because you have to say that you are going to make it. I argued, this is an RSVP form so you have to accept if you are RSVPing. That’s the point of the RSVP! Only people RSVP would bother submitting the form!  Pat wasn’t too happy about that and ask/told me to fix it. 

Digging into it, it turns out the way  for validates_presence_of relies on Object#blank which of course when sent

false.blank? # returns true

Reading up on the documentation, it is suggested to use validates_inclusion_of when dealing with booleans.

The one line change solved the problem:

validates_inclusion_of :accepted, :in => [true, false]
Using validates_presence_of on a boolean field? Should use validates_inclusion_of!

Setting up Phusion Passenger (mod_rails) with Capistrano support

Theo, , , 1 Comment

I had heard of mod_rails awhile back but never had the time to take a closer look at it. While setting up a new rails app, I was getting frustrated with all of the configuration I needed to do to get the mongrel clusters and proxy balancers setup. So I decided to give passenger a chance. I’m a fan now 🙂

The process was dead simple.

  1. Install the passenger gem 
    sudo gem install passenger
  2. Install passenger as an Apache module 
    passenger-install-apache2-module
  3. Load the passenger apache module by editing the Apache config 
    LoadModule passenger_module /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/ext/apache2/mod_passenger.so
PassengerRoot /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5
PassengerRuby /usr/bin/ruby1.8
  4. Restart Apache

If all things went well, you have everything installed you need. If there were some missing dependencies, you should be presented with how to install those dependencies.

In the installation output, it tells you how to mod_railsify your apps by creating a vhost as such:

<VirtualHost *:80>
    ServerName www.mywebsite.com
    DocumentRoot /home/deploy/mywebsite/public
</VirtualHost>

That’s it! No more of this proxy balancer and mongrel_cluster.yml configuration.

There’s some magic going on in the background. As requests come in, passenger will spin up more application instances. For more tweaking your configuration options check out the user guide.

Go to your website and you should see your rails app up and running.

So now we have your app up and running, how do we update or restart our app? Passenger provides two ways for us to do this.

The first is whenever apache is restarted, your application is restarted.

The second way allows us to restart a specified application without affecting Apache. Whenever passenger detects tmp/restart.txt, it will restart the application instances for us. We can integrate this into our Capistrano deploy flow by adding the following our config/deploy.rb

namespace :passenger do
  desc "Restart Application"
  task :restart do
    run "touch #{current_path}/tmp/restart.txt"
  end
end

after :deploy, "passenger:restart"

This will create that restart.txt after the cap:deploy task gets executed, causing the application to restart.

Finally, passenger comes with some pretty useful utilities.

Check out passenger-status which produces output showing current passenger server statuses.

Sample output: 

----------- General information -----------
max      = 6
count    = 1
active   = 0
inactive = 1
Using global queue: no
Waiting on global queue: 0

----------- Applications -----------
/home/deploy/www.myapp.com/releases/20081206183156: 
  PID: 30784     Sessions: 0

Another utility passenger-memory-status gives you insight into how much memory is being used by apache and passenger.

Sample output:

-------------- Apache processes ---------------
PID    PPID   Threads  VMSize    Private  Name
-----------------------------------------------
12841  1      1        225.9 MB  0.0 MB   /usr/sbin/apache2 -k start
28294  12841  1        248.4 MB  21.4 MB  /usr/sbin/apache2 -k start
28300  12841  1        243.7 MB  0.5 MB   /usr/sbin/apache2 -k start
28306  12841  1        248.4 MB  4.4 MB   /usr/sbin/apache2 -k start
28357  12841  1        249.1 MB  19.8 MB  /usr/sbin/apache2 -k start
29400  12841  1        249.4 MB  3.7 MB   /usr/sbin/apache2 -k start
29788  12841  1        249.3 MB  21.7 MB  /usr/sbin/apache2 -k start
29834  12841  1        245.8 MB  18.9 MB  /usr/sbin/apache2 -k start
29836  12841  1        245.8 MB  9.3 MB   /usr/sbin/apache2 -k start
29868  12841  1        245.8 MB  2.4 MB   /usr/sbin/apache2 -k start
29870  12841  1        246.5 MB  5.2 MB   /usr/sbin/apache2 -k start
### Processes: 11
### Total private dirty RSS: 107.44 MB

--------- Passenger processes ----------
PID    Threads  VMSize    Private  Name
----------------------------------------
28031  10       15.3 MB   0.1 MB   /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/ext/apache2/ApplicationPoolServerExecutable 0 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.5/bin/passenger-spawn-server  /usr/bin/ruby1.8  /tmp/passenger_status.12841.fifo
28032  2        48.7 MB   0.6 MB   Passenger spawn server
29161  1        114.8 MB  0.7 MB   Passenger FrameworkSpawner: 2.1.2
30461  1        122.8 MB  32.3 MB  Passenger ApplicationSpawner: /home/deploy/www.myapp.com/releases/20081206183156
30784  1        129.3 MB  33.4 MB  Rails: /home/deploy/www.myapp.com/releases/20081206183156
### Processes: 5
### Total private dirty RSS: 67.08 MB

Pretty sweet.

Setting up Phusion Passenger (mod_rails) with Capistrano support

undefined local variable or method `remote_gemspecs’

Theo, 12 Comments

I decided I wanted to dedicate some time this weekend working on some side projects. Of course before I start, I needed to get the latest and greatest updates so I ran gem update and got the following error

theo@theo~/dev $ sudo gem update
Updating installed gems
...
Updating rubygems-update
Successfully installed rubygems-update-1.3.1
ERROR:  While executing gem ... (NameError)
    undefined local variable or method `remote_gemspecs' for #

Reading the release notes:

NOTE: RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed. You will need to follow the second set of update
instructions if you see “Nothing to update”.

shows that we need to install and run the rubygem-update gem to get this fixed

  theo@theo~/dev $ sudo gem install rubygems-update
Successfully installed rubygems-update-1.3.1
1 gem installed
  theo@theo~/dev $ sudo update_rubygems 
Installing RubyGems 1.3.1
mkdir -p /Library/Ruby/Site/1.8
mkdir -p /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin
install -c -m 0644 rbconfig/datadir.rb /Library/Ruby/Site/1.8/rbconfig/datadir.rb
install -c -m 0644 rubygems/builder.rb /Library/Ruby/Site/1.8/rubygems/builder.rb
install -c -m 0644 rubygems/command.rb /Library/Ruby/Site/1.8/rubygems/command.rb
install -c -m 0644 rubygems/command_manager.rb /Library/Ruby/Site/1.8/rubygems/command_manager.rb
install -c -m 0644 rubygems/commands/build_command.rb /Library/Ruby/Site/1.8/rubygems/commands/build_command.rb
install -c -m 0644 rubygems/commands/cert_command.rb /Library/Ruby/Site/1.8/rubygems/commands/cert_command.rb
install -c -m 0644 rubygems/commands/check_command.rb /Library/Ruby/Site/1.8/rubygems/commands/check_command.rb
install -c -m 0644 rubygems/commands/cleanup_command.rb /Library/Ruby/Site/1.8/rubygems/commands/cleanup_command.rb
install -c -m 0644 rubygems/commands/contents_command.rb /Library/Ruby/Site/1.8/rubygems/commands/contents_command.rb
install -c -m 0644 rubygems/commands/dependency_command.rb /Library/Ruby/Site/1.8/rubygems/commands/dependency_command.rb
install -c -m 0644 rubygems/commands/environment_command.rb /Library/Ruby/Site/1.8/rubygems/commands/environment_command.rb
install -c -m 0644 rubygems/commands/fetch_command.rb /Library/Ruby/Site/1.8/rubygems/commands/fetch_command.rb
install -c -m 0644 rubygems/commands/generate_index_command.rb /Library/Ruby/Site/1.8/rubygems/commands/generate_index_command.rb
install -c -m 0644 rubygems/commands/help_command.rb /Library/Ruby/Site/1.8/rubygems/commands/help_command.rb
install -c -m 0644 rubygems/commands/install_command.rb /Library/Ruby/Site/1.8/rubygems/commands/install_command.rb
install -c -m 0644 rubygems/commands/list_command.rb /Library/Ruby/Site/1.8/rubygems/commands/list_command.rb
install -c -m 0644 rubygems/commands/lock_command.rb /Library/Ruby/Site/1.8/rubygems/commands/lock_command.rb
install -c -m 0644 rubygems/commands/mirror_command.rb /Library/Ruby/Site/1.8/rubygems/commands/mirror_command.rb
install -c -m 0644 rubygems/commands/outdated_command.rb /Library/Ruby/Site/1.8/rubygems/commands/outdated_command.rb
install -c -m 0644 rubygems/commands/pristine_command.rb /Library/Ruby/Site/1.8/rubygems/commands/pristine_command.rb
install -c -m 0644 rubygems/commands/query_command.rb /Library/Ruby/Site/1.8/rubygems/commands/query_command.rb
install -c -m 0644 rubygems/commands/rdoc_command.rb /Library/Ruby/Site/1.8/rubygems/commands/rdoc_command.rb
install -c -m 0644 rubygems/commands/search_command.rb /Library/Ruby/Site/1.8/rubygems/commands/search_command.rb
install -c -m 0644 rubygems/commands/server_command.rb /Library/Ruby/Site/1.8/rubygems/commands/server_command.rb
install -c -m 0644 rubygems/commands/sources_command.rb /Library/Ruby/Site/1.8/rubygems/commands/sources_command.rb
install -c -m 0644 rubygems/commands/specification_command.rb /Library/Ruby/Site/1.8/rubygems/commands/specification_command.rb
install -c -m 0644 rubygems/commands/stale_command.rb /Library/Ruby/Site/1.8/rubygems/commands/stale_command.rb
install -c -m 0644 rubygems/commands/uninstall_command.rb /Library/Ruby/Site/1.8/rubygems/commands/uninstall_command.rb
install -c -m 0644 rubygems/commands/unpack_command.rb /Library/Ruby/Site/1.8/rubygems/commands/unpack_command.rb
install -c -m 0644 rubygems/commands/update_command.rb /Library/Ruby/Site/1.8/rubygems/commands/update_command.rb
install -c -m 0644 rubygems/commands/which_command.rb /Library/Ruby/Site/1.8/rubygems/commands/which_command.rb
install -c -m 0644 rubygems/config_file.rb /Library/Ruby/Site/1.8/rubygems/config_file.rb
install -c -m 0644 rubygems/custom_require.rb /Library/Ruby/Site/1.8/rubygems/custom_require.rb
install -c -m 0644 rubygems/defaults.rb /Library/Ruby/Site/1.8/rubygems/defaults.rb
install -c -m 0644 rubygems/dependency.rb /Library/Ruby/Site/1.8/rubygems/dependency.rb
install -c -m 0644 rubygems/dependency_installer.rb /Library/Ruby/Site/1.8/rubygems/dependency_installer.rb
install -c -m 0644 rubygems/dependency_list.rb /Library/Ruby/Site/1.8/rubygems/dependency_list.rb
install -c -m 0644 rubygems/digest/digest_adapter.rb /Library/Ruby/Site/1.8/rubygems/digest/digest_adapter.rb
install -c -m 0644 rubygems/digest/md5.rb /Library/Ruby/Site/1.8/rubygems/digest/md5.rb
install -c -m 0644 rubygems/digest/sha1.rb /Library/Ruby/Site/1.8/rubygems/digest/sha1.rb
install -c -m 0644 rubygems/digest/sha2.rb /Library/Ruby/Site/1.8/rubygems/digest/sha2.rb
install -c -m 0644 rubygems/doc_manager.rb /Library/Ruby/Site/1.8/rubygems/doc_manager.rb
install -c -m 0644 rubygems/exceptions.rb /Library/Ruby/Site/1.8/rubygems/exceptions.rb
install -c -m 0644 rubygems/ext/builder.rb /Library/Ruby/Site/1.8/rubygems/ext/builder.rb
install -c -m 0644 rubygems/ext/configure_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/configure_builder.rb
install -c -m 0644 rubygems/ext/ext_conf_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/ext_conf_builder.rb
install -c -m 0644 rubygems/ext/rake_builder.rb /Library/Ruby/Site/1.8/rubygems/ext/rake_builder.rb
install -c -m 0644 rubygems/ext.rb /Library/Ruby/Site/1.8/rubygems/ext.rb
install -c -m 0644 rubygems/format.rb /Library/Ruby/Site/1.8/rubygems/format.rb
install -c -m 0644 rubygems/gem_openssl.rb /Library/Ruby/Site/1.8/rubygems/gem_openssl.rb
install -c -m 0644 rubygems/gem_path_searcher.rb /Library/Ruby/Site/1.8/rubygems/gem_path_searcher.rb
install -c -m 0644 rubygems/gem_runner.rb /Library/Ruby/Site/1.8/rubygems/gem_runner.rb
install -c -m 0644 rubygems/indexer.rb /Library/Ruby/Site/1.8/rubygems/indexer.rb
install -c -m 0644 rubygems/install_update_options.rb /Library/Ruby/Site/1.8/rubygems/install_update_options.rb
install -c -m 0644 rubygems/installer.rb /Library/Ruby/Site/1.8/rubygems/installer.rb
install -c -m 0644 rubygems/local_remote_options.rb /Library/Ruby/Site/1.8/rubygems/local_remote_options.rb
install -c -m 0644 rubygems/old_format.rb /Library/Ruby/Site/1.8/rubygems/old_format.rb
install -c -m 0644 rubygems/package/f_sync_dir.rb /Library/Ruby/Site/1.8/rubygems/package/f_sync_dir.rb
install -c -m 0644 rubygems/package/tar_header.rb /Library/Ruby/Site/1.8/rubygems/package/tar_header.rb
install -c -m 0644 rubygems/package/tar_input.rb /Library/Ruby/Site/1.8/rubygems/package/tar_input.rb
install -c -m 0644 rubygems/package/tar_output.rb /Library/Ruby/Site/1.8/rubygems/package/tar_output.rb
install -c -m 0644 rubygems/package/tar_reader/entry.rb /Library/Ruby/Site/1.8/rubygems/package/tar_reader/entry.rb
install -c -m 0644 rubygems/package/tar_reader.rb /Library/Ruby/Site/1.8/rubygems/package/tar_reader.rb
install -c -m 0644 rubygems/package/tar_writer.rb /Library/Ruby/Site/1.8/rubygems/package/tar_writer.rb
install -c -m 0644 rubygems/package.rb /Library/Ruby/Site/1.8/rubygems/package.rb
install -c -m 0644 rubygems/platform.rb /Library/Ruby/Site/1.8/rubygems/platform.rb
install -c -m 0644 rubygems/remote_fetcher.rb /Library/Ruby/Site/1.8/rubygems/remote_fetcher.rb
install -c -m 0644 rubygems/require_paths_builder.rb /Library/Ruby/Site/1.8/rubygems/require_paths_builder.rb
install -c -m 0644 rubygems/requirement.rb /Library/Ruby/Site/1.8/rubygems/requirement.rb
install -c -m 0644 rubygems/rubygems_version.rb /Library/Ruby/Site/1.8/rubygems/rubygems_version.rb
install -c -m 0644 rubygems/security.rb /Library/Ruby/Site/1.8/rubygems/security.rb
install -c -m 0644 rubygems/server.rb /Library/Ruby/Site/1.8/rubygems/server.rb
install -c -m 0644 rubygems/source_index.rb /Library/Ruby/Site/1.8/rubygems/source_index.rb
install -c -m 0644 rubygems/source_info_cache.rb /Library/Ruby/Site/1.8/rubygems/source_info_cache.rb
install -c -m 0644 rubygems/source_info_cache_entry.rb /Library/Ruby/Site/1.8/rubygems/source_info_cache_entry.rb
install -c -m 0644 rubygems/spec_fetcher.rb /Library/Ruby/Site/1.8/rubygems/spec_fetcher.rb
install -c -m 0644 rubygems/specification.rb /Library/Ruby/Site/1.8/rubygems/specification.rb
install -c -m 0644 rubygems/test_utilities.rb /Library/Ruby/Site/1.8/rubygems/test_utilities.rb
install -c -m 0644 rubygems/timer.rb /Library/Ruby/Site/1.8/rubygems/timer.rb
install -c -m 0644 rubygems/uninstaller.rb /Library/Ruby/Site/1.8/rubygems/uninstaller.rb
install -c -m 0644 rubygems/user_interaction.rb /Library/Ruby/Site/1.8/rubygems/user_interaction.rb
install -c -m 0644 rubygems/validator.rb /Library/Ruby/Site/1.8/rubygems/validator.rb
install -c -m 0644 rubygems/version.rb /Library/Ruby/Site/1.8/rubygems/version.rb
install -c -m 0644 rubygems/version_option.rb /Library/Ruby/Site/1.8/rubygems/version_option.rb
install -c -m 0644 rubygems.rb /Library/Ruby/Site/1.8/rubygems.rb
install -c -m 0644 ubygems.rb /Library/Ruby/Site/1.8/ubygems.rb
cp gem /tmp/gem
install -c -m 0755 /tmp/gem /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/gem
rm /tmp/gem
rm -f /Users/theo/.gem/source_cache
rm -f /Library/Ruby/Gems/1.8/source_cache
Removing old RubyGems RDoc and ri
rm -rf /Library/Ruby/Gems/1.8/doc/rubygems-1.2.0
Installing rubygems-1.3.1 ri into /Library/Ruby/Gems/1.8/doc/rubygems-1.3.1/ri
Installing rubygems-1.3.1 rdoc into /Library/Ruby/Gems/1.8/doc/rubygems-1.3.1/rdoc

------------------------------------------------------------------------------

= Announce: RubyGems Release 1.3.0

NOTE:  RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed.  You will need to follow the second set of update
instructions if you see "Nothing to update".

Release 1.3.0 fixes some bugs.

Bugs fixed:

* Disregard ownership of ~ under Windows while creating ~/.gem.  Fixes
  issues related to no uid support under Windows.
* Fix requires for Gem::inflate, Gem::deflate, etc.
* Make Gem.dir respect :gemhome value from config.  (Note: this feature may be
  removed since it is hard to implement on 1.9.)
* Kernel methods are now private.  Patch #20801 by Stefan Rusterholz.
* Gem::location_of_caller now behaves on Windows.  Patch by Daniel Berger.
* Silence PATH warning.

Deprecation Notices:

* Gem::manage_gems will be removed on or after March 2009.

For a full list of changes to RubyGems and the contributor for each change, see
the ChangeLog file.

Special thanks to Chad Wooley for backwards compatibility testing and Luis
Lavena for continuing windows support.

== How can I get RubyGems?

NOTE:  If you have installed RubyGems using a package system you may want to
install a new RubyGems through the same packaging system.

If you have a recent version of RubyGems (0.8.5 or later), then all
you need to do is:

  $ gem update --system   (you might need to be admin/root)

NOTE:  RubyGems 1.1 and 1.2 have problems upgrading when there is no
rubygems-update installed.  You will need to follow the second set of update
instructions if you see "Nothing to update".

NOTE: You may have to run the command twice if you have any previosly
installed rubygems-update gems.

If you have an older version of RubyGems installed, then you can still
do it in two steps:

  $ gem install rubygems-update  (again, might need to be admin/root)
  $ update_rubygems              (... here too)

If you don't have any gems install, there is still the pre-gem
approach to getting software ... doing it manually:

1. DOWNLOAD FROM: http://rubyforge.org/frs/?group_id=126
2. UNPACK INTO A DIRECTORY AND CD THERE
3. INSTALL WITH:  ruby setup.rb  (you may need admin/root privilege)

== To File Bugs

The RubyGems bug tracker can be found on RubyForge at:
http://rubyforge.org/tracker/?func=add&group_id=126&atid=575

When filing a bug, `gem env` output will be helpful in diagnosing the issue.

If you find a bug where RubyGems crashes, please provide debug output. You can
do that with `gem --debug the_command`.

== Thanks

Keep those gems coming!

-- Jim & Chad & Eric (for the RubyGems team)


------------------------------------------------------------------------------

RubyGems installed the following executables:
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/gem

If `gem` was installed by a previous RubyGems installation, you may need
to remove it by hand.
undefined local variable or method `remote_gemspecs’

gem update fails – can’t find header files for ruby

Theo, 5 Comments

So, Pat got a new MacBook Pro. Little does she know, I’ve start to install programs that I would use if I just so happened to be on her computer. The laptop already had Leopard installed and all of its goodies but a bit of upgrading was called for. So, of course I had run gem update.

pats-macbook-pro:~ pat$ sudo gem update

Updating installed gems

Updating RedCloth

Building native extensions.  This could take a while...

ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)

    ERROR: Failed to build gem native extension./System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb update

can't find header files for ruby.

Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/RedCloth-4.0.3 for inspection.

Results logged to /Library/Ruby/Gems/1.8/gems/RedCloth-4.0.3/ext/redcloth_scan/gem_make.out

But then I ran into a strange error I had never seen before. gem update would fail when trying to build native extension. It’s been awhile since I setup a rails development environment so a-googlin’ I went.

Turns out the ruby headers don’t come installed with the base ruby install with Mac OS X. These can been found on Mac OS X Install Disc 2 by installing the XCode Tools.

Once installed, all was well!

gem update fails – can’t find header files for ruby

Ruby: ! versus not operator

Theo, 1 Comment

I was writing some code in an erb template that looked like this:

<% if @user && not @user.errors.empty? -%>
#do stuff
<% end -%>

This resulted in a syntax error. Huh? What’s wrong with this?

Turns out it’s an outstanding Core Ruby bug.

As shown in the ticket if we have a method foo

def foo(parameter)
  puts parameter.to_s
end

using the ! and the not operator on various method calls show us that the ! and not operator are not interchangeable in practice.

foo(!(1 < 2)) # works fine
foo(not(1 < 2)) # generates syntax error
foo(not 1 < 2) # generates syntax error
foo((not 1 < 2)) # works fine

Changing the my code to the following fixed my issue:

<% if @user && !@user.errors.empty? -%>
#do stuff
<% end -%>
Ruby: ! versus not operator