http://www.pervasivecode.com/blog Jamie Flournoy's Software Development Blog Fri, 19 Mar 2010 05:37:52 +0000 http://backend.userland.com/rss092 en Migrations are one of the best features of Rails. Although some folks prefer pure SQL rather than Rails migration DSL, I don't know of anyone who dislikes the idea of a versioned schema that can evolve in a controlled and repeatable fashion. But because the concept of database migrations is such ... http://www.pervasivecode.com/blog/2010/03/18/rails-migration-antipatterns-and-how-to-fix-them/ Nokogiri on a standard installation of Leopard is complain-y about a couple of old libraries: "HI. You're using libxml2 version 2.6.16 which is over 4 years old and has plenty of bugs. We suggest that for maximum HTML/XML parsing pleasure, you upgrade your version of libxml2 and re-install nokogiri. ... http://www.pervasivecode.com/blog/2010/03/17/making-bundler-0-8-5-install-nokogiri-on-leopard-with-a-newish-libxml/ I'm trying out Ruby Version Manager this week, and my first impression is that this is some cool technology. But I wasn't able to figure out how to get it to install an older version of REE to get around this bug (the "Marshal.load reentered at marshal_load" issue). Igor P's solution ... http://www.pervasivecode.com/blog/2010/03/16/using-rvm-to-install-ree-1-8-7-2009-10/ Argh! I spent about 5 hours yesterday troubleshooting a failed Ubuntu Jaunty -> Karmic (9.04->9.10) upgrade. It worked fine until I rebooted and then failed to boot. Here's how I fixed it. It failed to boot, saying this: One or more mounts listed in /etc/fstab cannot yet be mounted / : waiting for ... http://www.pervasivecode.com/blog/2010/02/07/karmic-on-xen-with-bad-etcfstab-pain/ Once again Ubuntu Linux proves itself to be easy to upgrade. Going from 9.04 to 9.10 (one release newer, since their numbering is bsaed on dates) was easy, but included the standard sprinkling of manual re-customization that I've come to expect from Debian based systems. I did the Network Upgrade for ... http://www.pervasivecode.com/blog/2010/02/06/ubuntu-910-jaunty-jackalope-upgrade-notes/ Rails provides some flexible and fairly short controller methods for responding with an HTTP error code. Given that controllers are complicated enough by nature, I'm always looking for ways to DRY them up and make the code easy to understand. So here are some controller methods that make it really ... http://www.pervasivecode.com/blog/2009/07/27/tidier-http-error-responses-in-rails-controllers/ Rails controllers can get out of hand if you're not very careful. Skinny Controller Fat Model is a great start. But what about handling errors? Isn't it enough to just let Rails catch your exception and show a 500 Server Error page? No, it's not. Falling back on 500 Server Error ... http://www.pervasivecode.com/blog/2009/07/27/proper-error-handling-in-rails-controllers/ I had some problems with a view in a Rails app that was conditionally hiding a Google Map that was generated using the YM4R plugin. I don't usually test views in unit tests, and this logic depended on a particular situation with the data behind the view, so I decided ... http://www.pervasivecode.com/blog/2009/07/27/a-cucumber-step-to-test-for-a-ym4r-google-map/ I'm working on a Rails app that uses the ym4r_gm plugin, getting Google to do the geocoding for Thentic. I liked the idea of stubbing the web service call, because all those calls to an external service add up to over 20 seconds of test suite run time(!). That's almost ... http://www.pervasivecode.com/blog/2009/07/23/fancier-stubbing-of-geokit-for-rails-unit-tests/ I'm at WordCamp San Francisco today and decided that running a year old version of WordPress (on a year old version of Ubuntu Linux) was undesirable. So, with the confidence that comes from many relatively easy Ubuntu OS upgrades, I charged ahead. For (I think) the second time ever, things ... http://www.pervasivecode.com/blog/2009/05/30/ubuntu-jaunty-jackalope-upgrade-notes/