Things Trotter Likes

Things Trotter Likes http://trotter.posterous.com Most recent posts at Things Trotter Likes posterous.com Sun, 14 Mar 2010 16:11:27 -0700 Spatula: The Handy Chef Helper http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/Yv0r5JM_3uM/spatula-the-handy-chef-helper http://trotter.posterous.com/spatula-the-handy-chef-helper <p> <p>I've been hacking a bit on Spatula (<a href="http://github.com/trotter/spatula">http://github.com/trotter/spatula</a> and <a href="http://rubygems.org/gems/spatula">http://rubygems.org/gems/spatula</a>). Don't know if I've mentioned it here before, but it's a command line tool packaged as a gem that is supposed to help finding <a href="http://wiki.opscode.com/display/chef/Home">Chef</a> recipes and running chef-solo. It's definitely not fully ready, but it's at least ready enough to start playing around with on ubuntu instances. For instance, you can do something like:</p> <div class="CodeRay"> <div class="code"><pre>$ spatula search mysql $ spatula install mysql</pre></div> </div> <p>This will find all cookbooks on <a href="http://cookbooks.opscode.com">http://cookbooks.opscode.com</a> that match "mysql." It'll then download and install the one called "mysql" into your cookbooks directory. I find it slightly simpler than going through the web interface, downloading a tgz, and extracting it. I want to extend spatula to support other types of sources (like git repos), but haven't done so yet.</p> <p>Of course, even better than finding cookbooks is getting a new machine up and running. For this purpose, spatula has "prepare" and "cook". Prepare will ssh into the machine and install all the dependencies necessary for chef to actually run. Cook will rsync your cookbooks to the server, ssh in, and run chef-solo to cook the machine. We're using this at Hoopla to successfully build new machines / deploy to them in < 5 minutes. Yea, that's pretty hot.</p> <p>As an aside, I'm also going to be <a href="http://phillyemergingtech.com/sessions/chef-saving-time-and-money-with-automated-provisioning">speaking about Chef</a> at <a href="http://phillyemergingtech.com/">Philly Emerging Tech</a>. It's April 8th and 9th in Philly and has a great speaker lineup.</p> </p> <p><a href="http://trotter.posterous.com/spatula-the-handy-chef-helper">Permalink</a> | <a href="http://trotter.posterous.com/spatula-the-handy-chef-helper#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/Yv0r5JM_3uM" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/spatula-the-handy-chef-helper Thu, 04 Feb 2010 18:53:53 -0800 Philly Emerging Tech http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/Fr90kRH4lqY/philly-emerging-tech http://trotter.posterous.com/philly-emerging-tech <p> <p>Yay! Kyle Burton and I are speaking at <a href="http://www.phillyemergingtech.com">Philly Emerging Tech</a> this year. We'll be talking about what we've done at Algorithmics to put together our amazing stack. Seriously, it's pretty cool. We're running Clojure, RabbitMQ, and Rails, doing the bulk of our QA with <a href="http://www.cukes.info">Cucumber</a>, and currently transitioning our provisioning to <a href="http://wiki.opscode.com/display/chef/Home">Chef</a>. The talk is <a href="http://www.phillyemergingtech.com/sessions/living-on-the-bleeding-edge-a-case-study-in-using-clojure-amqp-chef-cucumber-and-jruby-in-the-financial-industry">Living on the Bleeding Edge: A Case Study in Using Clojure, AMQP, Chef, Cucumber and JRuby in the Financial Industry</a>, and I think it'll be really good. I hope to see you there!</p> </p> <p><a href="http://trotter.posterous.com/philly-emerging-tech">Permalink</a> | <a href="http://trotter.posterous.com/philly-emerging-tech#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/Fr90kRH4lqY" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/philly-emerging-tech Sat, 07 Nov 2009 09:04:44 -0800 Pair programming http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/5kZvfSe30E8/pair-programming-1 http://trotter.posterous.com/pair-programming-1 <p> <div class='p_embed p_image_embed'> <a href="http://posterous.com/getfile/files.posterous.com/trotter/ypIdtJKpw5v4UY4XHdZqmIFOTmGsIKIUyUTQCHnSXZ5awAlccReGyzWf2A1p/photo.jpg"><img alt="Photo" height="667" src="http://posterous.com/getfile/files.posterous.com/trotter/WcQzBUiw6PnBXjYSPGluyVB1IiolCBwblesEfYMqT24VGiw4TuSnDLovAfvv/photo.jpg.scaled.500.jpg" width="500" /></a> </div> <p>I can eat bugz?</p> </p> <p><a href="http://trotter.posterous.com/pair-programming-1">Permalink</a> | <a href="http://trotter.posterous.com/pair-programming-1#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/5kZvfSe30E8" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/pair-programming-1 Wed, 28 Oct 2009 07:54:47 -0700 The Matrix wasn't that far off http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/iB5OyYNHF3k/the-matrix-wasnt-that-far-off http://trotter.posterous.com/the-matrix-wasnt-that-far-off <p> <div class='p_embed p_video_embed'> <a href="http://trotter.posterous.com/the-matrix-wasnt-that-far-off"><img alt="" src="http://posterous.com/getfile/files.posterous.com/trotter/c1dYKrczseRakV8aouJsebXSUVf2nHF1HBABMU8JZKloufJmNksWwEhOhQSV/IMG_0843.png" /></a> <div class='p_embed_description'> <strong>IMG_0843.MOV</strong> <a href="http://trotter.posterous.com/the-matrix-wasnt-that-far-off">Watch on Posterous</a> </div> </div> <p>Apparently watching The Matrix had a bigger effect on my coding style <br />than I previously thought. Here you see automation at work.</p> </p> <p><a href="http://trotter.posterous.com/the-matrix-wasnt-that-far-off">Permalink</a> | <a href="http://trotter.posterous.com/the-matrix-wasnt-that-far-off#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/iB5OyYNHF3k" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/the-matrix-wasnt-that-far-off Thu, 22 Oct 2009 11:46:50 -0700 Our new pairing setup http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/m3WG7v5R-CE/our-new-pairing-setup http://trotter.posterous.com/our-new-pairing-setup <p> <div class='p_embed p_image_embed'> <a href="http://posterous.com/getfile/files.posterous.com/trotter/VJq217OAbQVt9BZuk9YE0vxBitXDv8xCHMAYFPFKDFeka9ICAQkKI0B2olqb/photo.jpg"><img alt="Photo" height="375" src="http://posterous.com/getfile/files.posterous.com/trotter/YZFF2MgrjoWF16L39WD8Qad1SFSmecdJGPgwzT9JOLN71aook5JeQRwGm3ir/photo.jpg.scaled.500.jpg" width="500" /></a> </div> <p>Bonnie got us chess clocks to make sure no one hogs the keyboard. Rock!</p> </p> <p><a href="http://trotter.posterous.com/our-new-pairing-setup">Permalink</a> | <a href="http://trotter.posterous.com/our-new-pairing-setup#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/m3WG7v5R-CE" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/our-new-pairing-setup Wed, 14 Oct 2009 11:01:09 -0700 Last Night's Cucumber Presentation http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/R7vi6bXeVQU/last-nights-cucumber-presentation http://trotter.posterous.com/last-nights-cucumber-presentation <p> <p>I've put the slides on slideshare. Embed is below.</p> <div style="text-align: left;"><a href="http://www.slideshare.net/trotter/unit-tests-arent-enough" title="Unit Tests Aren't Enough" style="font: 14px Helvetica,Arial,Sans-serif; display: block; margin: 12px 0 3px 0; text-decoration: underline;">Unit Tests Aren't Enough</a> <object height="355" width="425"> <param name="movie" value="http://static.slidesharecdn.com/swf/ssplayer2.swf?doc=integration-testing-091014125601-phpapp02&stripped_title=unit-tests-arent-enough" /> <param name="allowFullScreen" value="true" /> <param name="allowScriptAccess" value="always" /><embed src="http://static.slidesharecdn.com/swf/ssplayer2.swf?doc=integration-testing-091014125601-phpapp02&stripped_title=unit-tests-arent-enough" type="application/x-shockwave-flash" height="355" width="425"></embed> </object> <div style="font-size: 11px; font-family: tahoma,arial; height: 26px; padding-top: 2px;">View more <a href="http://www.slideshare.net/" style="text-decoration: underline;">presentations</a> from <a href="http://www.slideshare.net/trotter" style="text-decoration: underline;">Trotter Cashion</a>.</div> </div> </p> <p><a href="http://trotter.posterous.com/last-nights-cucumber-presentation">Permalink</a> | <a href="http://trotter.posterous.com/last-nights-cucumber-presentation#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/R7vi6bXeVQU" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/last-nights-cucumber-presentation Tue, 13 Oct 2009 10:20:48 -0700 Google Building Maker Rocks! http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/SBvkfifiGF4/google-building-maker-rocks http://trotter.posterous.com/google-building-maker-rocks <p> <div class="posterous_bookmarklet_entry"> <blockquote class="posterous_long_quote">One of the best ways to get a big project done — and done well — is to open it up to the world. As such, today we're announcing the launch of <a href="http://www.google.com/buildingmaker">Google Building Maker</a>, a fun and simple (and crazy addictive, it turns out) tool for creating buildings for <a href="http://earth.google.com/">Google Earth</a>.</blockquote> <div class="posterous_quote_citation">via <a href="http://googleblog.blogspot.com/2009/10/introducing-google-building-maker.html">googleblog.blogspot.com</a></div> <p>Just tried this out and it's crazy easy. Used it to pretend to make my apartment building slightly better. Obviously, I'll have to get better so that my deck looks right.</p></div> </p> <p><a href="http://trotter.posterous.com/google-building-maker-rocks">Permalink</a> | <a href="http://trotter.posterous.com/google-building-maker-rocks#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/SBvkfifiGF4" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/google-building-maker-rocks Tue, 13 Oct 2009 05:02:39 -0700 Ruby Readline http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/5r8zjCk-7VU/ruby-readline http://trotter.posterous.com/ruby-readline <p> <div class="posterous_bookmarklet_entry"> <blockquote class="posterous_long_quote"><h2 style="cursor: pointer;">Basic Functionality</h2> <p>Here is the standard Ruby readline sample program:</p> <div class="CodeRay"> <div class="code"><pre>require 'readline' while line = Readline.readline('> ', true) p line end</pre></div> </div> <p>With that you already have your keyboard shortcuts and basic history management. Lets dig into the details and then add features on top of this.</p></blockquote> <div class="posterous_quote_citation">via <a href="http://bogojoker.com/readline/">bogojoker.com</a></div> <p>Readline in Ruby is much simpler than I thought. Just added it to cuke-talker.</p></div> </p> <p><a href="http://trotter.posterous.com/ruby-readline">Permalink</a> | <a href="http://trotter.posterous.com/ruby-readline#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/5r8zjCk-7VU" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/ruby-readline Fri, 09 Oct 2009 11:03:17 -0700 Xpath in Clojure http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/v8aJjCuhCbk/xpath-in-clojure http://trotter.posterous.com/xpath-in-clojure <p> <p>Cool xpath library for Clojure written by Kyle (and me a little). <a href="http://github.com/kyleburton/clj-xpath">http://github.com/kyleburton/clj-xpath</a></p> </p> <p><a href="http://trotter.posterous.com/xpath-in-clojure">Permalink</a> | <a href="http://trotter.posterous.com/xpath-in-clojure#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/v8aJjCuhCbk" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/xpath-in-clojure Tue, 06 Oct 2009 05:24:32 -0700 Cruise Control Builder http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/LLcvp0TMCe8/cruise-control-builder http://trotter.posterous.com/cruise-control-builder <p> <p>We wrote a plugin to build our Rails project for CruiseControl. We needed it because we're using the old school Java Cruise Control. Check it out on github: <a href="http://github.com/trotter/cruise_control_builder/fast_forward">http://github.com/trotter/cruise_control_builder/fast_forward</a></p> </p> <p><a href="http://trotter.posterous.com/cruise-control-builder">Permalink</a> | <a href="http://trotter.posterous.com/cruise-control-builder#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/LLcvp0TMCe8" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/cruise-control-builder Sat, 03 Oct 2009 08:12:35 -0700 Arduino http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/36SJ9MIYIis/arduino-37 http://trotter.posterous.com/arduino-37 <p> <p>I've started playing around with Arduino lately. I've put my sketches up on github here: <a href="http://github.com/trotter/arduino-playground">http://github.com/trotter/arduino-playground</a>. I'll be adding to it as I figure out how to do more.</p> </p> <p><a href="http://trotter.posterous.com/arduino-37">Permalink</a> | <a href="http://trotter.posterous.com/arduino-37#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/36SJ9MIYIis" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/arduino-37 Thu, 01 Oct 2009 09:53:43 -0700 ChicagoBoss http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/zn6lJDoGkZg/chicagoboss http://trotter.posterous.com/chicagoboss <p> <p>Chicago Boss (<a href="http://www.chicagoboss.org/index.html)">http://www.chicagoboss.org/index.html)</a> looks pretty cool. It's basically just Rails / Django in Erlang... but still looks pretty fun. May try it out on a project soon.</p> </p> <p><a href="http://trotter.posterous.com/chicagoboss">Permalink</a> | <a href="http://trotter.posterous.com/chicagoboss#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/zn6lJDoGkZg" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/chicagoboss Thu, 01 Oct 2009 08:27:22 -0700 CruiseControl http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/tjAeFBq4rXE/cruisecontrol http://trotter.posterous.com/cruisecontrol <p> CruiseControl will misbehave if your timezone isn't set and will say that all your builds ran 4 hours ago. To fix the problem, be sure to do "export TZ=EDT" (or your timezone) in your bashrc or in cruisecontrol.sh. </p> <p><a href="http://trotter.posterous.com/cruisecontrol">Permalink</a> | <a href="http://trotter.posterous.com/cruisecontrol#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/tjAeFBq4rXE" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/cruisecontrol Sun, 27 Sep 2009 09:43:00 -0700 HTTP/1.1: Header Field Definitions http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/sq5k2PHJM7E/http11-header-field-definitions http://trotter.posterous.com/http11-header-field-definitions <p> <div class="posterous_bookmarklet_entry"> <div class="posterous_quote_citation">Have a look at the http spec at <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html">http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html</a><br /></div> <p>It's always good to know your http headers.</p> </div> </p> <p><a href="http://trotter.posterous.com/http11-header-field-definitions">Permalink</a> | <a href="http://trotter.posterous.com/http11-header-field-definitions#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/sq5k2PHJM7E" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/http11-header-field-definitions Sun, 27 Sep 2009 06:51:52 -0700 Fibonacis and Clojure http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/I2NCvmAILN0/fibonacis-and-clojure http://trotter.posterous.com/fibonacis-and-clojure <p> <p>Here's some Clojure I cooked up while playing with Fibonaci numbers. It's a very succinct language when it comes to manipulating lists.</p> <div class="CodeRay"> <div class="code"><pre>(defn fibonacis ([] (concat [0 1] (fibonacis 0 1))) ([a b] (let [n (+ a b)] (lazy-seq (cons n (fibonacis b n))))))(defn small-fibonacis [] (take-while #(< % 4000000) (fibonacis)))(defn small-even-fibonacis [] (filter even? (small-fibonacis)))</pre></div> </div> </p> <p><a href="http://trotter.posterous.com/fibonacis-and-clojure">Permalink</a> | <a href="http://trotter.posterous.com/fibonacis-and-clojure#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/I2NCvmAILN0" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/fibonacis-and-clojure Thu, 24 Sep 2009 09:31:00 -0700 XKCD the book http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/GrzD3pLvcCI/xkcd-the-book http://trotter.posterous.com/xkcd-the-book <p> <p>I has it.</p> <p><div class='p_embed p_image_embed'> <a href="http://posterous.com/getfile/files.posterous.com/trotter/UrSi46KUsdDQG9ZB0oV5awBPeiQkqLKvoYVbuafkLfOe3nnhfOUiOHV6XYQc/photo.jpg"><img alt="Photo" height="667" src="http://posterous.com/getfile/files.posterous.com/trotter/6AG0vOIpHrT25Xu4pjngN5lQL14MxXM8ImOlqvVnh1tyDKir5XCFROt3TvWU/photo.jpg.scaled.500.jpg" width="500" /></a> </div> </p> </p> <p><a href="http://trotter.posterous.com/xkcd-the-book">Permalink</a> | <a href="http://trotter.posterous.com/xkcd-the-book#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/GrzD3pLvcCI" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/xkcd-the-book Thu, 24 Sep 2009 06:12:00 -0700 All the McDonald's in the US http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/jG4PWb9Pc_s/mcdushighjpg-jpeg-image-1240x900-pixels-scale http://trotter.posterous.com/mcdushighjpg-jpeg-image-1240x900-pixels-scale <p> <div class="posterous_bookmarklet_entry"><div class='p_embed p_image_embed'> <a href="http://posterous.com/getfile/files.posterous.com/trotter/pqdJFwjDBzgDFvquayjnwEiJwpAbqtHjsBxhEaqzqJFxttdGHudFHHzDIlCp/media_httpmediaweathersealedcommapsmcdushighjpg_yhfHHjJshHtunIJ.jpg.scaled1000.jpg"><img alt="Media_httpmediaweathersealedcommapsmcdushighjpg_yhfhhjjshhtunij" height="363" src="http://posterous.com/getfile/files.posterous.com/trotter/pqdJFwjDBzgDFvquayjnwEiJwpAbqtHjsBxhEaqzqJFxttdGHudFHHzDIlCp/media_httpmediaweathersealedcommapsmcdushighjpg_yhfHHjJshHtunIJ.jpg.scaled500.jpg" width="500" /></a> </div> <div class="posterous_quote_citation">via <a href="http://media.weathersealed.com/maps/mcd_us_high.jpg">media.weathersealed.com</a></div> <p>Wow, McDonald's is everywhere.</p> </div> </p> <p><a href="http://trotter.posterous.com/mcdushighjpg-jpeg-image-1240x900-pixels-scale">Permalink</a> | <a href="http://trotter.posterous.com/mcdushighjpg-jpeg-image-1240x900-pixels-scale#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/jG4PWb9Pc_s" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/mcdushighjpg-jpeg-image-1240x900-pixels-scale Tue, 22 Sep 2009 11:00:25 -0700 Single Table Inheritance and Grandchildren in Rails http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/5uKq16P_oMg/single-table-inheritance-and-grandchildren-in http://trotter.posterous.com/single-table-inheritance-and-grandchildren-in <p> <p>We currently have a problem at work where we have an inheritance heirarchy like so:</p> <div class="CodeRay"> <div class="code"><pre>class Shape < ActiveRecord::Base; endclass Square < Shape; endclass Round < Shape; endclass Circle < Round; endclass Ellipse < Round; end</pre></div> </div> <p>It's your standard single table inheritance, except that you have to grandchildren classes of Circle and Ellipse. It's these grandchildren that cause our problems. When you do a <code>Shape.find(:all)</code> in normal STI, Rails executes <code>select * from shapes</code>. When you do a Round.find(:all), Rails executes <code>select * from shapes where type = 'Round'</code>. Umm... that's wrong. What's more fun though, is that Rails will correct itself once it learns about the Circle and Ellipse classes. If you do <code>Circle.find(:all)</code>, then the query is correct. In addition, your <code>Round.find(:all)</code> call after that will be correct as well.</p> <p>To fix the problem, we decided on a hack that forces Rails to know about the grandchildren classes. We've defined the Round class like so:</p> <div class="CodeRay"> <div class="code"><pre>class Round < ShapeendCircle unless caller.detect? { |c| c =~ /circle/ }Ellipse unless caller.detect? { |c| c =~ /ellipse/ }</pre></div> </div> <p>This forces Rails to lookup and load the Circle and Ellipse classes when it loads Round *and* doesn't load the Circle or Ellipse if we're loading Round because of the inheritance call in Circle or Ellipse. That last part is important because you get a circular look-up if you don't have it.</p> <p>Needless to say, I do not like this solution. It's hacky and requires me to maintain information about the heirarchy that is already in the code elsewhere. Does anyone know of a better solution to this problem? I'm also open to areas of Rails to think about patching. I'm more than happy to get my hands dirty, but I'm hoping someone else has already solved this problem.</p> <p>PS - This only happens in dev mode (I think). It appears that caching classes forces Rails to know about the subclasses at the beginning.</p> </p> <p><a href="http://trotter.posterous.com/single-table-inheritance-and-grandchildren-in">Permalink</a> | <a href="http://trotter.posterous.com/single-table-inheritance-and-grandchildren-in#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/5uKq16P_oMg" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/single-table-inheritance-and-grandchildren-in Sun, 20 Sep 2009 10:42:00 -0700 Telnet is fun http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/oYY3pI6Rjpc/telnet-is-fun http://trotter.posterous.com/telnet-is-fun <p> <p>$ telnet <a href="http://cnn.com">cnn.com</a> 80<br />> GET / HTTP/1.1<br />> host: <a href="http://www.cnn.com">www.cnn.com</a><p />Wammo, it kicks out a page. Now you know HTTP.</p> <p><strong>Update:</strong> Eric points out that you can do "telnet cnn.com http" when you can't remember the port for http.</p> </p> <p><a href="http://trotter.posterous.com/telnet-is-fun">Permalink</a> | <a href="http://trotter.posterous.com/telnet-is-fun#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/oYY3pI6Rjpc" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/telnet-is-fun Sat, 19 Sep 2009 16:05:14 -0700 Newflow Is Ready http://feedproxy.google.com/~r/ThingsTrotterLikes/~3/Nav4gOUExvQ/newflow-is-ready http://trotter.posterous.com/newflow-is-ready <p> <p>I spent some time today fixing up the remaining bugs in Newflow. It should now be completely compatible with Rails and installable as a gem from github. <a href="http://github.com/trotter/newflow">http://github.com/trotter/newflow</a></p> </p> <p><a href="http://trotter.posterous.com/newflow-is-ready">Permalink</a> | <a href="http://trotter.posterous.com/newflow-is-ready#comment">Leave a comment  »</a> </p><img src="http://feeds.feedburner.com/~r/ThingsTrotterLikes/~4/Nav4gOUExvQ" height="1" width="1"/> http://files.posterous.com/user_profile_pics/173731/PIC_0104.JPG http://posterous.com/users/4Q3afLWwa Trotter Cashion Trotter Trotter Cashion http://trotter.posterous.com/newflow-is-ready