http://www.42.mach7x.com Thoughts and tips about programming with Ruby on Rails Mon, 23 Jun 2008 09:03:06 +0000 http://backend.userland.com/rss092 en Problem You want to send emails from a Ruby on Rails application, when there is a specific condition on a database table. If the database table gets modified by another application outside Rails you cannot use an observer model. Solution We already assume that: You are using a database You have a model named voicemail ... http://www.42.mach7x.com/2008/06/11/ruby-on-rails-email-scheduling-using-runner-and-cron/ Problem To get used to the new ways of working with Rails 2. Solution Here are some of the new ways of doing things in Rails 2. Create a scaffold and migration on one step: ./script/generate scaffold product fied1_name:string field2_name:string field3_name:float Make sure that you don't have any previous migration(ie ... http://www.42.mach7x.com/2008/05/28/rails-2-new-ways/ Problem Upgrading an existing Ruby on Rails application from 1.2.3, to 2.0.2, presents few problems. I will try and keep a record of the ones I encounter along the way, here. Solution Change the config/environment.rb to let the application know to use the 2.0.2 gem rail version, change ... http://www.42.mach7x.com/2008/05/24/upgrading-ruby-on-rails-application-from-123-to-202/ Today, there was an announcement about Dreamhost, having the new Passenger (mod_rails) feature ready for use with Ruby on Rails applications. The full announcement is here. It should be changing the way Rails applications are deployed, making it much easier. http://www.42.mach7x.com/2008/05/13/dreamhost-passenger-mod_rails-announced/ Problem You want to find out your UID for a specific domain that you have set up with google analytics. Solution When you first create the tracking code for your website, it's quite obvious how to get the UID for that specific website. If you decide later on to change your site, from drupal ... http://www.42.mach7x.com/2008/05/08/google-analytics-uid/ Problem You want to pass the £ sign to an http service, but the ruby CGI.escape encodes it incorrectly. Solution After using ruby's CGI.escape for the string as: sms_msg_tmp=CGI.escape(sms_code) then replace the encoding with the pound sign encoding as in: sms_msg=sms_msg_tmp.gsub('%C2%A3','%A3') It should then pass the correct value for the £ sign. http://www.42.mach7x.com/2008/05/07/ruby-incorrect-encoding-of-pound-sign/ Problem You want to disable your rails web site for maintenance, but your application uses an older capistrano version than the one currently installed. Solution According to the RubyOnRails Cookbook recipe 13.12, it should only be a case of running cap disable_web (enable_web). But in the meantime you have upgraded your capistrano version to ... http://www.42.mach7x.com/2008/05/07/disabling-rails-web-site-when-using-mongrelapachecapistrano-141/ Problem Trying to use the heroku gem to clone a project and do local modifications I got the following error: git: fatal error: `chdir' failed: permission denied. Solution It turns out that in Mandriva, when using: sudo urpmi git what gets installed is the 'GNU Interactive Tools' that has nothing to do with the git version ... http://www.42.mach7x.com/2008/04/24/git-fatal-error-chdir-failed-permission-denied/ Problem Trying to use ExtJS with RubyOnRails on Heroku, gives the following error and a blank page in Firebug. Ext.ux.grid has no properties ... Line 141 Solution In Heroku, you will probably have to manually upload the files from the ExtJS library, as well as the ext_scaffold plugin. When you do that, two files that ext_scaffold needs, ... http://www.42.mach7x.com/2008/04/23/extuxgrid-has-no-properties-error/ Problem You want to convert some legacy tables created in Paradox (.db, .px) to another format so you can use it in MySQL. Solution Download the px tools from here. Follow the instructions, in the INSTALL file after you untar the file. You should have to do the usual three step linux installation: configure make sudo make install Afterwards ... http://www.42.mach7x.com/2008/04/21/converting-paradox-tables-to-mysql-in-linux/