what did i learn today
Uncategorized ruby on rails rspec
skipping slow tests in rspec2

For Test::Unit there is a module called skippy, that allows you to skip for instance slow tests. I was looking for a way to achieve the same in Rspec. I am currently developing against Rails 3.0.0.rc, and using rspec 2.0.0.beta.19 and could not find anything. So i asked on the rspec mailing list and got a great answer! It is actually present in rspec2, right out of the box, as a feature they needed for their own tests. Read the description by David himself here. He shows a lot of very good examples, even filtering tests based on ruby-version is now possible. Awesome. In short, you would do something like : [ruby] describe "something", :slow => true do it "should be blabla" end describe "something else" do it "should be a slow test", :slow => true do ... end it "should be a fast test" do .. end end [/ruby] then you can write the following to skip the slow tests : [ruby] # in spec/spec_helper.rb RSpec.configure do |c| c.filter_run_excluding :slow => true end [/ruby] and to run only the slow tests: [ruby] # in spec/spec_helper.rb RSpec.configure do |c| c.filter_run :slow => true end [/ruby] and to filter on slow tests, and run all tests if no slow tests are available: [ruby] # in spec/spec_helper.rb RSpec.configure do |c| c.filter_run :slow => true c.run_all_when_everything_filtered = true end [/ruby] Awesome! :) For the moment there is no command-line support, but in the spec/spec_helper.rb you could also check for any environment variables to do the slow or fast test-set. What i personally needed, was something that would either run all tests, or run all tests excluding a few (i have a test-suite for an sms-gateway and do not want to send sms-es all the time). So i handled that like this: [ruby] # in spec/spec_helper.rb RSpec.configure do |config| if ENV['SEND_REAL_SMS'] != "true" config.filter_run_excluding :send_sms => true end end [/ruby]

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Uncategorized submodules git plugins rails
Using git-submodule to handle plugins

Using git-submodule can make it very easy for you to work with plugins in your rails projects. I will try to show you this, in an easy step-by-step manner. To start, make a plugin-project, call it your_plugin, in its own folder, and push the code to git. Your standard commands apply, as for any project:

  • git status : what is changed?
  • git add . : add the newly added files to your git-repository
  • git commit -am "a meaningful message" : commit your changes in your local repository
  • git push origin master : push your local changes to the remote master (origin/master) How can you add the plugin as a submodule to your rails project? Navigate to the root of your rails project, and execute the following commands: [bash] git submodule add git://your_repository vendor/plugins/your_plugin_name git submodule init git submodule update git status # will show the difference: only the submodule is added git commit -a -m "added plugin your-plugin-name" [/bash] How do you retrieve the lastest version of a submodule/plugin. A submodule in git is coupled to the git-repository at a specific time, so it does not automatically evolve with the remote versions of your pluging. You have to manually make a few operations, to make sure you are using the latest version. In my opinion this is an advantage, as you can keep using a known working version until you really want to upgrade. To update your submodule, go to the root of your plugin/submodule (normally RAILS_ROOT/vendor/plugins/your-plugin-name), and execute the following commands: [bash] git remote update # since your submodule is actually a git repository on its own, you can do this git merge origin/master # retrieve the remote master version cd ...... # back to RAILS_ROOT git status # your submodule is updated to the latest version [/bash] Now to edit and change the plugin/submodule, it is the easiest to work inside the plugin folder itself. To do so, you have to proceed as follows. Inside the root of your plugin (e.g. @\vendor\plugins\your-plugin@) [bash] git checkout -b your_local_branch ... do some changes git commit -a -m "something changed" git checkout master git pull git checkout your_local_branch git rebase master ... solve posslble merge-conflicts ... git checkout master git merge your_local_branch git push [/bash] then cd to RAILS_ROOT [bash] git status # => your plugin will have changed git commit -a -m "improved plugin" [/bash] I used the following sources for inspiration:
  • using git-submodules to track plugins
  • git submodules in n easy steps
  • agile git and the story branch pattern
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Uncategorized rails3 activerecord rails
rewriting find_by_sql for rails 3

I am starting in Rails 3. I have a simple situation where i would select a parent based on a condition of one of its children. Normally i would write something like: [ruby] Distributor.find_by_sql("select d.*, c.rate from distributors d, coverages c where c.country_code_id = 25 and order by rate asc") [/ruby] Although this works, it is not the best solution to take. For one, it is vulnerable to sql-injection and secondly it shows a lot of the underlying database structure, and on top of that the sql-implementation could change between databases. In Rails 3 i can now write [ruby] Distributor.includes(:coverages).where("coverages.country_code_id=? and =coverages.distributor_id", 25).order(:rate) [/ruby] This is so readable! Awesome :)

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Uncategorized ruby rvm ubuntu
installing ubuntu for ruby development

I have made the complete switch. My home development machine is no longer Windows XP, no longer dual booting Ubuntu but a full-fledged Ubuntu. After installing the dual-boot, and my machine at work this is the third time to install an ubuntu machine, and getting everything ready for ruby development. I just want to archive my steps here, so a next time could be even faster :) Installing Ubuntu 10.04 itself is a piece of cake. My first step after the installation is to enable numlock on login screen (i always use numbers in my passwords) [bash] sudo apt-get install numlockx [/bash] Then run sudo gedit /etc/gdm/Init/Default and find the line [bash] exit 0 [/bash] and add the following code above that line [bash] if [-x /usr/bin/numlockx]; then /usr/bin/numlockx on fi [/bash] Secondly I install rvm for multiple rubies. We first need to install any ruby for that. Take the default ubuntu version (1.8). [bash] sudo apt-get install ruby rubygems [/bash] This does not install the latest version, but we don't need that yet. Rvm will solve this for us. Install rvm itself: [bash] sudo apt-get install curl bison build-essential zlib1g-dev libssl-dev libreadline5-dev libxml2-dev git-core bash < <( curl ) [/bash] Then make sure rvm will work always [bash] sudo gedit .bashrc [/bash] and replace [-z $SP1] && return with [bash] if [[! -z $SP1]]; then .. original content that was below the && return line [[-s $HOME/.rvm/scripts/rvm]] && source $HOME/.rvm/scripts/rvm fi #EOF [/bash] Then rvm should be available. Install the needed rubies. We use ree at work, i like to work with 1.9.1/2 and i want to check out rubinius. So install your rubies through rvm [bash] rvm install ree rvm install 1.9.2 rvm install rbx [/bash] Installing ruby 1.9.1 was a bit harder, when i just tried to run the standard rvm install 1.9.1, i received the following error: [bash] .rvm/src/ruby-1.9.1-p429/lib/optparse.rb:1310: [BUG] Segmentation fault [/bash] and that was caused because i use a newer gcc version, which can't handle the -O3 optimisation. It took me a while to find how you can fix it, but in the end (as always) it was easy. Just type [bash] export optflags="-O0"; rvm install 1.9.1 [/bash] To end, set your default ruby version [bash] rvm ree --default [/bash] now all your new sessions you should be using your selected default version. After installing your favourite editor (Netbeans or rubymine), your favourite database (postgreSQL, sqlite, mysql ), and your list of gems you are ready to roll some ruby! I must say as an previously avid Windows user for ages, i am very impressed by Ubuntu. This is a free operating system, and while i was aware that everything just works better being linux (meaning processes and filesystem); but not only that: it even looks better and is very user-friendly. It is way more customisable looks-wise then silly windows. In Windows 7 for instance you have to use this very large font, and in Ubuntu i can set the size to anything i want (small!!!). Awesome :) And i guess it will amaze me for the next few days and weeks whilst finding out other new stuff. [UPDATE] For me it is confusing that the minimize, maximize and close buttons are on the left-side, i think it is done to be more apple-like. But the fix to move the buttons to the right is luckily very easy once you know it :)

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Uncategorized limited stock shopping cart subjective usability
shopping cart usability

Last wednesday i was offered, in a mail i received, the opportunity to start shopping on friday at 1500hours CET for an very specific item, Instant film at an incredible price. So come last friday, I was ready and braced to start shopping. Unfortunately and to be expected, i was not alone. I was able to get 3 packs of film in my shopping basket, enter my details, select a payment method, and ... just when all I needed to do was confirm the whole thing the site hung up on me and when the site reacted again all stock was gone. This felt very wrong: I was almost there, I had the items in my shopping cart, i was in the checkout line, i should have been able to buy it. It got me thinking how to handle such a thing. So out of this negative experience, i mailed to the support of the site, claiming the way they handled the shopping cart was wrong (maybe i should have said: could be improved), because i was expecting that if i could place items in the shopping basket, i would also be able to buy them; and also to be able to let them know i was unhappy, and hoping they could do something about it come next time. They did reply, though:

Sorry, but that's the way our shop works: until you click the "place order" button, the stock is not reserved for you. Only by confirming your order, you are then guaranteed the order. Stock is subtracted not upon successful payment, but the moment you confirm your order. The payment is then processed and your order marked as "paid" and passed on to processing.

While their approach makes sense for normal e-commerce sites, sites where the stock is limited ask for another approach. Of course, as a developer it becomes more difficult to get items out of stock once they are placed in the shopping cart, most especially because when to release the items to stock if the customer does not buy? I did find another article, explaining when retailers should empty a shopping cart. From the article i deduced some rules:

  • if your stock is limited, placing items in the shopping cart should reserve the item (removing it from available stock temporarily), so you have a difference between the actual stock (what the retailer has in their storage, reserved stock (about to be sold or not) and sold stock). So the amount of stock visible on the site should be actual stock-reserved stock.
  • how long your shopping cart is valid should be visible or communicated (e.g. countdown clock) I would like to note that this is especially true for ticketing services, where stock is in very limited supply and in large demand. You want to give the user the good shopping experience (when a customer puts the items in the shopping basket, there still was stock, so he or she should be able to buy them), but also not let your users hoard the stock. An excellent example from the above-mentioned article is Ticketmaster, where a user can put tickets in her basket, and then has a predefined time (two minutes) to complete the purchase or the cart is emptied and the stock released again. As a consequence, the meaning of your shopping cart is different: it is a clear intention to buy, so it will not be used as a wish list. On e-commerce sites where there is no such peak of sales, shopping carts can even persist over different sessions, allowing returning users to continue shopping. Such a use of a shopping cart would not be linked to the stock directly (e.g. reserving items), but whether an item is in stock would be checked at the start of a new session. This is in high contrast with an e-commerce site offering items which are in very limited supply and high demand (like tickets or instant film). The standard approach does not suffice. If putting items in the shopping basket takes them out of the stock, the load can be spread more evenly. Let me explain that by example, by comparing 2 scenarios. Scenario 1, the standard e-commerce site, items are only taken out of stock after an order is confirmed:
  • 1000's of people log on
  • all of them add a number of items to their shopping basket
  • all of them start filling in their details, payment methods, delivery address, and all this has to be verified, connections to Paypal, credit-card service, ...
  • in the meantime no items have been sold, so users logging on can still start buying things, thereby adding more load to the server, ...
  • the server bends under the escalating load Now compare this to scenario two, where items are being "reserved" if they are put inside the shopping basket, and a user has two minutes to complete the order-confirmation process:
  • 1000's of people log on
  • 400 or more of those people get rejected, because the items have been reserved
  • the users who were able to get items in the basket, fill in the details, which have to be verified, ...
  • users logging on later will in the meantime not be able to order anything, because all items have been reserved
  • after the first two minutes have passed, most of those first items will have been bought, and some will have released again
  • some users will be able to fetch released items and can continue shopping This scenario will not only communicate better to your clients, the process is clearer, AND the load on your servers can't escalate in the same way. This process could then be further improved, so that users logging on are placed in a FIFO queue. The first users to place an order get their items until stock runs out. The following ones are placed in a waiting queue, and busy-wait at most the two minutes (the maximum time before items could be released) for those that are released, if any. If a user has no patience, he releases his place in the queue. If you add to that some real-time communication (pushing to the client?), you would have a real clean a user-friendly system. From the moment a user logs on, it is clear what is going on.
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Uncategorized actionmailer attachments windows ruby on rails
actionmailer attachments on windows

I have been having troubles sending e-mails using ActionMailer on windows. The simple code-sample: [ruby] my_filename="my_image.jpeg" attachment "image/jpeg" do |a| a.body = a.filename = File.basename(my_filename) end [/ruby] did not work. I did find an attachment inside my e-mail, but it was corrupt. It took me a while to figure out it could be something related to my development platform, which unfortunately still is windows (not for long). On windows reading binary files is less obvious, apparently, so you need to write: [ruby] my_filename="my_image.jpeg" attachment "image/jpeg" do |a| a.body =,'rb') { |f|} a.filename = File.basename(my_filename) end [/ruby] ... and this will work! :) I you have to combine normal e-mail content and one or more attachments, this then becomes something like: [ruby] # we send a mail to respond to a mention def mention_response(given_subject, addressee, pdf_attachment = nil) from APP_CONFIG["mail"]["from"] recipients addressee.to_a subject given_subject content_type "multipart/mixed" part "text/html" do |p| p.body = render_message("mention_response", :thr_name => thr_name) end attachment :content_type => "application/doc" do |a| a.filename File.basename(pdf_attachment) a.body, "rb") { |f| } end unless pdf_attachment.nil? end [/ruby] Nice :)

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Uncategorized ruby strings
use %q to create strings

In my gemspec created by jeweler I saw string creating using %Q. What? [ruby] gem.summary = %Q{TODO: one-line summary of your gem} gem.description = %Q{TODO: longer description of your gem} [/ruby] I found a pagedescribing ruby string creation, and it seems %Q is the equivalent of double quote delimited strings and %q is the equivalent of single quotes. While i was pondering what the advantage could be of writing it that way, i opened up irb and look and behold: [ruby] irb(main):001:0> test = %Q{ggg gggg ggg} => "ggg gggg ggg" irb(main):002:0> test2= "ff ff ff" => "ff ff ff" irb(main):003:0> test= %Q{%q{ffff ffff ffff}} => "%q{ffff ffff ffff}" irb(main):004:0> test= %Q{this is a "test", curious whether 'it' works :)} => "this is a "test", curious whether 'it' works :)" irb(main):005:0> test= %Q{this is a "test", i am curious whether #{test2} 'it' works :)} => "this is a "test", i am curious whether ff ff ff 'it' works :)" irb(main):006:0> [/ruby] Cool! It allows you to write your strings without having to think about escaping the quotes.

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Uncategorized dual boot wubi ubuntu
easiest dual boot ubuntu install

I wanted to convert my XP laptop to a dual boot with Ubuntu or Kubuntu. Whichever. I want to try out linux and maybe switch altogether. Run windows inside a Virtualbox if i would really need it (e.g. for work). So i looked up different tutorials, while i was cleaning up disk-space and suddenly bumped into Wubi. I assumed i had to play with partitions and bootsectors, but the Wubi-installer manages all that for you. Just download the program (1.4MB!), run it, fill in a user and password and it takes all the work out of your hands. Completely automatic. Ideal for me ;)

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Uncategorized ruby mingw32 plugin git
script/plugin install from git fails

I am using ruby 1.8.7 on windows (mingw32), and all of a sudden i cannot run [ruby] c:\> ruby script/plugin install git:// Plugin not found: ["git://"] [/ruby] the suggested variations also don't work, e.g. [ruby] ruby script/plugin install ruby script/plugin install [/ruby] all give the same error. But, apparently, it has something to do with the mingw32 platform. In C:\Ruby\lib\ruby\gems\1.8\gems\activesupport-2.3.5\lib\active_support\core_ext\kernel\reporting.rb the following line can be found in function silence_stream: [ruby] stream.reopen(RUBY_PLATFORM =~ /mswin/ ? 'NUL:' : '/dev/null') [/ruby] Replace that with the correct way to check for the windows platform, and then all should be fine again :) [ruby] stream.reopen(RUBY_PLATFORM =~ /mswin|mingw/ ? 'NUL:' : '/dev/null') [/ruby] I still needed to replace git:// with http:// but now it works :) Now investigate how this can be pushed to Rails codebase?

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Uncategorized javascript observe_field ruby on rails
keeping observe_field and spinner in sync

I am using a lot of observe_fields in my views. I have two searches on my form, one with two fields one with four, and every time a user types something the observe_field is triggered and some search is executed via AJAX. To make sure the user knows what is going on, i use a spinner-image. [ruby] <%= observe_field 'querypeople', :frequency => 1, :update => 'people_to_link', :before => "'spinner2')", :loaded => "Element.hide('spinner2')", :complete => "Element.hide('spinner2')", :url => {:action => 'listpeople'}, :with => " 'querypeople=' +escape($('querypeople').value) + '&queryorganisation=' + escape($('queryorganisation').value)" %> <%= observe_field 'queryorganisation', :frequency => 1, :update => 'people_to_link', :before => "'spinner2')", :loaded => "Element.hide('spinner2')", :complete => "Element.hide('spinner2')", :url => {:action => 'listpeople'}, :with => " 'querypeople=' +escape($('querypeople').value) + '&queryorganisation=' + escape($('queryorganisation').value)" %> [/ruby] This works all fine and dandy, but when a user types multiple characters in a row, the spinner is hidden while another query is running. So i needed to improve that. I first introduced a little code to count how many times a certain spinner is shown: [ruby] <% javascript_tag do %> var spinner_counter=[0,0,0]; function show_spinner(itm) { spinner = (itm == 0) ? "spinner2" : "spinner" ;; spinner_counter[itm] = spinner_counter[itm] + 1; } function hide_spinner(itm) { spinner = (itm == 0) ? "spinner2" : "spinner" ; spinner_counter[itm] = spinner_counter[itm] - 1; if (spinner_counter[itm] <= 0) { Element.hide(spinner); spinner_counter[itm] = 0; } } <% end %> [/ruby] and then adapted the ruby-code as follows: [ruby] <%= observe_field 'querypeople', :frequency => 1, :update => 'people_to_link', :before => "show_spinner(0)", :complete => "hide_spinner(0)", :url => {:action => 'listpeople'}, :with => " 'querypeople=' +escape($('querypeople').value) + '&queryorganisation=' + escape($('queryorganisation').value)" %> <%= observe_field 'queryorganisation', :frequency => 1, :update => 'people_to_link', :before => "show_spinner(0)", :complete => "hide_spinner(0)", :url => {:action => 'listpeople'}, :with => " 'querypeople=' +escape($('querypeople').value) + '&queryorganisation=' + escape($('queryorganisation').value)" %> [/ruby] Do you know a better solution?

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Uncategorized mongrel service thin windows ruby on rails
mongrel_service beta troubles with space

I am switching back from using thin inside a service to mongrel_service, because when my thin-process is killed somehow, the service stills seems to be running. Mongrel_service can cope with this much better: it also keeps a check on your ruby process and restarts it if needed (at least in the old version, i hope the 0.4.beta3 prerelease version behaves the same). When using the mongrel_service (gem install mongrel_service --pre) on ruby 1.8.7 you can no longer have a space inside the name. So if you run the following command: [bash] mongrel_rails service::install -N "Name with a space" -c c:\path\to\your\app -p 4000 -e production [/bash] there will be no output as to whether it succeeded or not on XP, on Windows Server 2008 a more appropriate error is shown; but the service will not be created. The trouble is the name: it contains a space, and apparently that is no longer allowed. On the old MRI and previous mongrel_service it was not a problem. The old version, however, does not work in ruby 1.8.7 from, due to a dependency to some very specific Visual C++ code regarding service communication (and now the ruby is compiled using gcc). Luckily there is an easy fix, as suggested by Luis Lavena himself: [bash] mongrel_rails service::install -N name_without_space -D "Name with a space" -c c:\path\to\your\app -p 4000 -e production [/bash]

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Uncategorized model mvc ruby on rails
accessing current_user in models

Up until now i was able to somehow circumvent the need to access the current-user in the model, by calling methods from the controllers and handing down the current-user. In the MVC pattern, the model should know as little as possible about things the controller handles. But now, i need a method that will check :before_save what has changed, and by whom, and will log that into another table (model). So i am going to create an Observerclass, that needs to access the model on the one hand, but needs to know the current-user on the other hand. First I found a very dirty but working solution. Put this in application.rb: [ruby] around_filter :you_dont_have_bloody_clue protected def you_dont_have_bloody_clue klasses = [ActiveRecord::Base, ActiveRecord::Base.class] methods = ["session", "cookies", "params", "request"] methods.each do |shenanigan| oops = instance_variable_get(:"@_#{shenanigan}") klasses.each do |klass| klass.send(:define_method, shenanigan, proc { oops }) end end yield methods.each do |shenanigan| klasses.each do |klass| klass.send :remove_method, shenanigan end end end [/ruby] This was credited to Pratik Naik, but at the same time highly NOT recommended by him. It seems a bit like a bulldozer approach. Actually it is nice to know such things are possible, and how to achieve it, but it (kind of) breaks the MVC pattern. So i looked further for a nicer solution. I found a really simple one here, and adapted it to my needs: [ruby] class User < ActiveRecord::Base cattr_accessor :current_user def self.current_user @current_user ||="dummy-user") end ... end class ApplicationController < ActionController::Base include AuthenticatedSystem before_filter { |c| User.current_user = session[:user] } end [/ruby] And now, inside each class, i can just use [ruby]User.current_user[/ruby]. I overwrite the current_user class method, so i don't have to set the user manually during tests (is that clean?). I am not sure if this is the best solution. I found a few more complicated ones, but this seems to fit me the best.

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News ruby arrrrcamp ruby on rails

Went to arrrrcamp last friday (Arrrr as in _R_uby, _R_ails, _R_adiant and, of course, _R_hum!). It was the third edition of this unique ruby-on-rails event, and the third time i visited it ;) So i am a regular :) The first year i was just starting ruby and my then-collegue and me learned a lot. The second time i took some new collegues along hoping to get them infected with the ruby virus. This year i went alone (so you can guess how well the infection spread :), but one advantage of being alone in a croud is that it is way easier to mingle. There's even a picture to prove it :) I saw some very interesting talks:

  • Something Something Mongo: I alrready had read about Mongo, and was interested. This speech interested me more than Radiant. Just another NoSQL database. Some things were not entirely clear, like how you can query stuff if all things are in the same "database". But it seems like something i should investigate more. I think there are a lot of possible applications, and the presenter showed a very good example, where the database is entirely configurable by the end-user, which is dead-easy in Mongo and MongoMapper, because there is no schema! Ha! :) Opens up possibilities indeed ;)
  • jQuery on Rails: at the same time there was a talk about the new things in Rails3. So this was a hard choice. But i am already using jQuery, in combination with Prototype, and was hoping to get some tips to do it better. The talk was very quick, but also very informative. The presenter did a very cool job, where he showed the same site in Prototype (using helpers) and jQuery (using unobtrusive javascript). Very nice. I still write most of my javascript inline, and am gradually switching over. I am still struggling with one problem. In most of unobtrusive javascript examples, i always see that all code is placed in the application.js. But that is not good enough for me. I want a js file per erb-file. I found a blogpost by Yehuda Katz, where he does something even smarter: only include the js-files which include the selectors from the current page. But unfortunately it is so old, the source is nowhere to be found anymore. when i asked the presenter, after the session, he pointed me to this article about Jzip, but on second look it is not quite what i am looking for.
  • Railties: what, why & how?: a very interesting talk, but i must admit, since Rails 3 territory is still very unknown to me (and a lot has changed apparently) a lot of it was unclear. In short: the old way to create rails plugins is replaced by Railties. Plugins and engines are supported, dependencies are more explicit. Something i still need to look into, to convert the plugin we use at work.
  • Something something Rack: actually i did not want to see this one, but rather the 12 hours to rate a rails website by Elise Huard, but because @Atog was late those two talks had switched. She confided, however, that i would get a second change at RailsConf :) The something-something-rack talk was very basic, but also enlightning. Rack provides a minimal interface between webservers supporting Ruby and Ruby frameworks. Rack applications can be stacked. Since Rails is a Rack application, it is now very easy to put Rack-apps in front of Rails, for instance to redirect to different sites or pages if the visitor uses a mobile device (Rack::MobileDetect), add google analytics to your pages automatically (Rack::GoogleAnalytics), or to block unallowed access (Rack::Warden). Very interesting. Also allows for a clean seperation of concerns. One last Rack middleware I really want to mention: Rack::ChromeFrame! This middleware will make sure the Google Chrome frame is automatically enabled. Cool :)
  • Learning to smile at your code: a talk by two german guys, who both work at Xing, about refactoring and to learn to actually enjoy it. Xing is a very big website, coded for the largest part in Rails. They have 22 developers working in Rails. Sebastian and Tim, the presenters, had to add features to the job-postings page/code and encountered a lot of problems doing so. I really liked this talk because i found it very recognisable and also because it was a talk focusing on the programming of an application as a whole. They used a lot of humour to convey their message, with success. Really-really compressed their message was: 1) seeing a lot of old, incomprehensible code can be demotivating; 2) breathe and relax; 3) starting to refactor it anyway, despite the obvious unwillingness at first, will make you smile because you can create something beautiful. They gave some examples which i guess barely even scratched the surface of the complexity they had to deal with. Nice :) After that the lightning talks came (short talks of about 10 minutes). I will highlight a few:
  • failtale: a notification framework/website by the guys from Mr. Henry. Impressive, because not only does it capture ruby/rails exceptions, but also ActionScript (flash) and Javascript soon. I am going to try that out! :) I am currently using Exception Notifier myself, curious how it compares.
  • The guys from 10-forward did three talks. First a demo of their application, which was incredibly impressive. Wow! Blew me away. A lot of javascript and ajax to make the website feel like a real application. Very powerful. Then they discussed a gem of theirs, and rspec and cucumber.
  • wallsome: Sebastian and Tim from Xing, who also did the Learning to smile talk, here presented their pet-project, using Rails 3 and jQuery: a wall to arrange your tasks from Basecamp like in Scrum or Kanban. I am looking forward to the next edition on the 29th of october! :)
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Uncategorized ruby word automation word2007
setting word bookmarks from ruby

The easy solution to set a bookmark inside a Word-document: [ruby] require 'win32ole' word ='Word.Application') doc = word.Documents.Add("#{path to your template here}") doc.Bookmarks("bookmark-name").Range.Text = "new content here" [/ruby] This will work, and will replace the bookmark with the text you wanted to insert. Recently i had to convert a document that was first built using mail-merge. I am not very familiar with mail-merge, but it seems a specific field can occur multiple times inside the document. This is very convenient. So i looked for a way to replace this behaviour, and still use bookmarks. I know how to set bookmarks programmatically, and this seemed easier than preparing a temporary document first for mail-merging. My first thought was that i create bookmarks, and give the duplicate bookmarks names like "#{original -bookmark-name}_2" , and inside my program i would go looking if there would be any copies (_2, _3, _4) and set them accordingly. But i looked further. There should be a better way. Luckily there does exist something called "REF" fields inside Word, which are fields that inherit their content from a certain bookmark! A-ha! But the above code won't work, because i actually replace the bookmark with the text, and then nothing is left to be reffered to :) So the code to set a bookmark turns a bit more complex: [ruby] require 'win32ole''Word.Application') doc = word.Documents.Add("#{your-template-path}") ## wdGoToBookmark = -1, wdCharacter = 1 word.Selection.GoTo("What" => -1, "Name" => "#{your-bookmark-name}") word.Selection.Delete("Unit" => 1, "Count" => 1) word.Selection.InsertAfter "#{your-new-text}" # re-create our bookmark doc.Bookmarks.Add("Range" => word.Selection.Range, "Name" => "#{your-bookmark-name}") # update all (referring) fields doc.Fields.Update # in Word2007, filetype 16 saves as a Word2003 compatible document, 12 is docx, 17 is pdf doc.SaveAs "#{your-filename}.doc", 16 [/ruby] [UPDATE] Actually, although this works, it doesn't work if two bookmarks are really close, e.g. only seperated by a single space. So the above is not the correct way. Some googling revealed the correct way: [ruby] # new version of code bm_name = "#{your-bookmark-name}" bm_range = doc.Bookmarks(bm_name).Range bm_range.Text = "insert something interesting here" doc.Bookmarks.Add bm_name, bm_range [/ruby] I hope this helps :)

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Uncategorized mongrel_service service thin windows rails
mongrel_service alternative: using thin and srvany

So i am developing and deploying Ruby on Rails applications on Windows. Recently i started experimenting with the newer versions of ruby (mingw32platform). One of the side-effects is that the mongrel-service, which i always used to deploy my rails-applications no longer works on mingw32. And aside of that, i have read on various instances [ref] that thin should be better (more efficient) than mongrel. But i still want to install it as a service. First off, you need to download and install the Windows Resource Kit. This contains the executables to make a service of any executable or script. Then create the service running (in the console): [bash] C:\Program Files\Windows Resource Kits\Tools> instsrv "[my_service_name]" "c:\program files\Windows Resource Kits\Tools\srvany.exe" The service was successfuly added! Make sure that you go into the Control Panel and use the Services applet to change the Account Name and Password that this newly installed service will use for its Security Context. [/bash] This will add an empty entry in the registry, which actually still does nothing. To get it working, we have to start regedit, and navigate to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services[my_service_name] Create a new key (folder) named Parameters. This will contain the settings of our actual application that will be run as a service. Add the following String Values: [bash] [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services[my_service_name]\Parameters] Application=c:\ruby\bin\ruby.exe AppDirectory=[my_ruby_app_folder] AppParameters=c:\ruby\bin\thin start -p 4000 -e production [/bash] Assuming that c:\ruby\bin is your ruby folder, and you want your thin to listen to port 4000. Once that is done, start the service, and your rails application should be up and running :)

... but Windows Server 2008

Unfortunately, to do this on Windows 2008 you need to perform some extra steps. As you can't install the resource kit on Windows Server 2008R2 for some peculiar reason, and at the time of this posting, i have not found a Windows Server 2008 Resource Kit Tools, so i took the following steps:

  1. copy the "srvany.exe " from the "Windows Server 2003 Resource Kit Tools " to a suitable location on your Win2008 server (e.g. C:\Windows\System32\ )
  2. use "sc " to create a new service that launches "srvany " (e.g. sc create MyService binPath= C:\Windows\System32\srvany.exe DisplayName= "My Custom Service" )
  3. using RegEdit create a "Parameters " key for your service as before and fill it with the 3 string values A bit more work, but not too much.


And just today I discovered an update of mongrel_service was announced, so you can still work using mongrel_service instead of using thin and manually creating the service. What you need to do:

  • install mongrel service: gem install mongrel_service --prerelease
  • create the service as before: mongrel_rails service::install -N myapp -c c:\my\path\to\myapp -p 4000 -e production That is much easier of course.
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Uncategorized ruby oci ruby-oci8 x64 windows
ruby-oci8 on x64: not a valid win32 executable

working on Windows Server 2008R2 64-bit, installing ruby 1.8.7, ruby-oci8 ran into the following error, after requiring 'oci8' : LoadError 193: %1 is not a valid Win32 applicationOn this machine a 64bit version of Oracle was installed. So the OCI.dll was a 64-bit version. The fix seemed easy: copy a 32-bit version of the OCI.dll. But I had to copy (from another 32-bit machine)

  • OCI.dll (32-bit)
  • MSVCR71.dll
  • ... and ORAOCIEI10.dll

to my ruby\bin folder, and then everything worked. Copying just the OCI.dll and MSVCR71.dll gave the puzzling error OCIError: OCI library initialization error.

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Uncategorized ruby refactoring rails
refactoring ruby code

Most of my ruby/rails development is against a legacy Oracle database. One of the things we needed to fix, was a user-table with not enough fields. Because the user table was shared with another application, we were not able to alter the table. So we added another table, user_params, containing possibly extra parameters for each user. Now it would be nice if each of those possible parameters would behave like a real attribute. So, first implementation: [ruby] class User < ActiveRecord::Base set_primary_key "user_name" set_table_name "stca_user" set_sequence_name "autogenerated" # do not use a sequence at insert! validates_presence_of :user_name validates_presence_of :password # define some virtual attributes for attributes defined in the UserParam table def group_name UserParam.get_param_value(self.user_name, 'UserGroup') end def group_name=(value) UserParam.set_param_value(self.user_name, 'UserGroup', value) end def title UserParam.get_param_value(self.user_name, 'UserTitle') end def title=(value) UserParam.set_param_value(self.user_name, 'UserTitle', value) end def language UserParam.get_param_value(self.user_name, 'UserLanguage') end def language=(value) UserParam.set_param_value(self.user_name, 'UserLanguage', value) end def full_name UserParam.get_param_value(self.user_name, 'UserFullName') end def full_name=(value) UserParam.set_param_value(self.user_name, 'UserFullName', value) end def email UserParam.get_param_value(self.user_name, 'UserEmail') end def email=(value) UserParam.set_param_value(self.user_name, 'UserEmail', value) end # ... snipped away more code end [/ruby] Obviously, this code is not DRY. At lot of repetition, like the stuff i hate about C# or java properties. This could be done better, let's just generate the methods: [ruby] class User < ActiveRecord::Base set_primary_key "user_name" set_table_name "stca_user" set_sequence_name "autogenerated" # do not use a sequence at insert! validates_presence_of :user_name validates_presence_of :password # define some virtual attributes for attributes defined in the UserParam table instance_eval do [['group_name', 'UserGroup'], ['title', 'UserTitle'], ['language','UserLanguage'], ['full_name', 'UserFullName'], ['email', 'UserEmail']].each do |arr| define_method arr[0].to_sym do UserParam.send('get_param_value', self.user_name, arr[1]) end define_method "#{arr[0]}=" do |value| UserParam.send("set_param_value", self.user_name, arr[1], value) end end end end [/ruby] This looks nice. One disadvantage might be that this is not very readable. At first glance it is no longer clear which attributes are available. But with models that is always the case. A few things can still be improved. Every get and set is a query against the database. We might want to improve upon that, and cache results. Also saving the virtual fields is now done when they are being set, but at that time the parent "User" might still not be saved. So this still calls for a better solution. But this does show why i like ruby so much. It makes me feel powerful :)

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Uncategorized oracle_enhanced_adapter oracle rails
rails and avoiding oracle sequences at insert

When using Rails on top of an Oracle database, you use the oracle enhanced activerecord adapter. This adapter (or Rails) has one weird side-effect: there is no way to avoid using a sequence when inserting a new record. But, in this comment, Raimonds Simanovskis hints at the solution. In an initializer you write: [ruby] # a small patch as proposed by the author of OracleEnhancedAdapter: # if a ActiveRecord model has a sequence with name "autogenerated", the id will not be filled in from any sequence ActiveRecord::ConnectionAdapters::OracleEnhancedAdapter.class_eval do alias_method :orig_next_sequence_value, :next_sequence_value def next_sequence_value(sequence_name) if sequence_name == 'autogenerated' # we assume id must have gotten a good value before insert! id else orig_next_sequence_value(sequence_name) end end end [/ruby] ... and in your model you add: [ruby] set_sequence_name 'autogenerated' [/ruby]

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Uncategorized ruby win32
multiple ruby versions on windows

I started developing ruby more than a year ago, on windows, which might not be the ideal platform :) But i started out with the standard one-click installer, ruby version 1.8.6, which up until recently served me fine and is an easy way to start. But when i felt the need to install metric_fu, i found out it just does not install on top of the old ruby 1.8.6 (mswin32). Now i know that for ruby 1.8.7 (mingw32) a development kit exists, which would allow compilation of all native code. So, normally, all plugins that were giving me problems before (e.g. thin!) should be able to be installed using that. Also the new rubyinstaller versions are known to be quicker, because they are using a more recent and efficient compiler (mingw), and ruby 1.9.1 should inherently be even more efficient (by design). But i was looking for an easy way to migrate and test ruby versions. I know that there exist a ruby version manager (rvm), but it only works on linux and mac. But luckily, for windows, there is pik. It is really easy to install: [bash] > gem install pik > pik_install c:\windows\system32 [/bash] [the choice to use windows\system32 is maybe not entirely kosher, but it is an easy way to add something to the path, always ;) Maybe i should have used c:\ruby\pik\bin and added that to the path.] Then add the current version as the default: [bash] > ruby -v ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] > pik add Adding: 186: ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] Located at: c:/ruby/bin [/bash] Then you can download the new versions, e.g. ruby 1.8.7. and 1.9.1 from rubyinstaller and install them each into their own folder. E.g. c:\ruby\187-p249\ and then issue the following command: [bash] > pik add c:\ruby\1.8.7-p249\bin ... > pik add c:\ruby\1.9.1-p378\bin ** Adding: 191: ruby 1.9.1p378 (2010-01-10 revision 26273) [i386-mingw32] Located at: c:\ruby\1.9.1-p378\bin > pik list 186: ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] * 187: ruby 1.8.7 (2010-01-10 patchlevel 249) [i386-mingw32] 191: ruby 1.9.1p378 (2010-01-10 revision 26273) [i386-mingw32] [/bash] But of course, the second problem is that the one-click installer also includes a lot gems by default, while the new rubyinstaller is almost empty. So first i installed the development kit from rubyinstaller. I needed to extract that inside the each ruby folder, and change a few settings (configure), like described here, i needed to edit my /devkit/msys/1.0.11/etc/fstab settings file, and replace c:\ruby by my actual ruby-installation folder, in my case something like c:\ruby\1.8.7-p249. I create a small batch-file to install all the missing gems: [bash] rem default windows gems call gem install win32-api call gem install win32-clipboard call gem install win32-dir call gem install win32-eventlog call gem install win32-file call gem install win32-file-stat call gem install win32-process call gem install win32-sapi call gem install win32-service call gem install win32-sound call gem install win32console call gem install windows-api call gem install windows-pr call gem install hpricot call gem install nokogiri call gem install wxruby rem RAILS call gem install rails call gem install will_paginate call gem install mongrel call gem install mongrel_service call gem install formtastic rem database gems call gem install sqlite3-ruby call gem install ruby-oci8 call gem install activerecord-oracle_enhanced-adapter call gem install builder call gem install calendar_date_select call gem install cgi_multipart_eof_fix call gem install composite_primary_keys call gem install log4r call gem install ezcrypto rem testing call gem install cucumber call gem install cucumber-rails call gem install factory_girl call gem install remarkable call gem install rspec call gem install rspec-rails [/bash] But i still encountered an error on the gems that needed to build native extensions: [bash] C:\WINDOWS>gem install hpricot Building native extensions. This could take a while... ERROR: Error installing hpricot: ERROR: Failed to build gem native extension. c:/Ruby/1.9.1-p378/bin/ruby.exe extconf.rb checking for stdio.h... yes creating Makefile make MAKE Version 5.2 Copyright (c) 1987, 2000 Borland Fatal: '/c/Ruby/1.9.1-p378/include/ruby-1.9.1/ruby.h' does not exist - don't know how to make it Gem files will remain installed in c:/Ruby/1.9.1-p378/lib/ruby/gems/1.9.1/gems/hpricot-0.8.2 for inspection. Results logged to c:/Ruby/1.9.1-p378/lib/ruby/gems/1.9.1/gems/hpricot-0.8.2/ext/fast_xs/gem_make.out [/bash] It took a good nights rest to figure that one out: i have Borland's Cbuilder 5 installed on my system to be able to maintain ancient software. So i had to remove that entry from my path, and after that all gems that needed native building went smoothly, except mongrel_service. Now everything installed just fine, inside my 1.8.7 system. Doing the same on ruby 1.9.1 took a lot longer, or so it seemed definitely. I think partly that is because ruby 1.9.1 seems to maintain a class cache? But i am not sure of that. But what surprised me even more is that actually all gems installed without any problem, except win32-service and because of that, mongrel_service. As explained here, this issue is known and due to the fact that the library relies on specific MSVC behaviour that mingw does not support. But i think i can create a service from about any executable or batch file. But i read herethat i have to issue the following command: [bash] c:\ruby> gem install mongrel_service --prerelease [/bash] The pre-release version removes the dependency of win32-service, and so it works again. So now i can start testing my applications inside 1.8.7 and 1.9.1 on windows, try using thin, and get metric_fu up and running.

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Uncategorized ruby exceptions actionmailer rails
exception notifier configuration troubles

I installed and configured exception notifier to be notified of any unexpected errors in our production environment. At first i tried this out in development, used gmail as my smtp server and all was working fine. My action mailer configuration looked as follows, in environment.rb: [ruby] # configure mailing config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { :enable_starttls_auto => true, :address => "", :port => "587", :domain => "localhost", :authentication => :plain, :user_name => "<snipped>", :password => "<snipped>" } ExceptionNotifier.exception_recipients = %w( ExceptionNotifier.sender_address = %("<snipped>") ExceptionNotifier.email_prefix = "[My Application ERROR] " [/ruby] Using this configuration worked, and i received the e-mails. Alas, as usual, on my client's production server the port to reach gmail was blocked, and when i asked to open it, they instead proposed to use their own smtp-server. So i changed the configuration as follows: [ruby] config.action_mailer.smtp_settings = { :address => "", :port => "25", :domain => "", :authentication => nil } ExceptionNotifier.exception_recipients = %w( ExceptionNotifier.sender_address = %("") ExceptionNotifier.email_prefix = "[My Application ERROR] " [/ruby] The first thing i did wrong was the domain-name. At first i wrote "" in my action-mailer configuration, so my HELO request was blocked. Secondly, apparently, because i wrote ExceptionNotifier.sender_address = %("") the sender address was not recognised and the mail was rejected by our own SMTP-server. This took me a while to figure out. Luckily our sys-admin noticed the difference. The fix: [ruby] ExceptionNotifier.sender_address = %( [/ruby] And now i know for sure that if i get no mails, my application really is working :)

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