Keep It Simple - Make It Simpler

Rails 1.2.4 changelogs

2007-10-05T11:29:00.000+02:00

Official announcement

The latest - and last - release in the Rails 1.2.x familly.

Rails 1.2.4 changelogs

http://dev.rubyonrails.org/changeset/7741

Indivitual changelogs : actionpack, activerecord, activesupport, railsties

root/tags/rel_1-2-4/railties/CHANGELOG 1.2.4 (October 4th, 2007)

Add a new rake task to aid debugging of named routes. $ rake routes
use Gem.find_name instead of search when freezing gems. Prevent false positives for other gems with rails in the name. Closes #8729 [wselman]
Fix syntax error in dispatcher than wrecked failsafe responses. #8625 [mtitorenko]
Add Active Resource to rails:freeze:edge and drop Action Web Service. #8205 [underbluewaters, Jeremy Kemper]
Give generate scaffold a more descriptive database message. Closes #7316 [jeremymcanally]
Canonicalize RAILS_ROOT by using File.expand_path on Windows, which doesn’t have to worry about symlinks, and Pathname#realpath elsewhere, which respects symlinks in relative paths but is incompatible with Windows. #6755 [Jeremy Kemper, trevor]

root/tags/rel_1-2-4/activesupport/CHANGELOG 1.4.3 (October 4th, 2007)

Demote Hash#to_xml to use XmlSimple#xml_in_string so it can’t read files or stdin. #8453 [candlerb, Jeremy Kemper]
Document Object#blank?. #6491 [Chris Mear]
Update Dependencies to ignore constants inherited from ancestors. Closes #6951. [Nicholas Seckar]
Improved multibyte performance by relying less on exception raising #8159 [Blaine]

root/tags/rel_1-2-4/activerecord/CHANGELOG 1.15.4 (October 4th, 2007)

Fix #count on a has_many :through association so that it recognizes the :uniq option. Closes #8801 [lifofifo]
Don’t clobber includes passed to has_many.count [danger]
Make sure has_many uses :include when counting [danger]
Save associated records only if the association is already loaded. #8713 [blaine]
Changing the :default Date format doesn’t break date quoting. #6312 [bshand, Elias]
Allow nil serialized attributes with a set class constraint. #7293 [sandofsky]
belongs_to assignment creates a new proxy rather than modifying its target in-place. #8412 [mmangino@elevatedrails.com]
Fix column type detection while loading fixtures. Closes #7987 [roderickvd]
Document deep eager includes. #6267 [Josh Susser, Dan Manges]
Oracle: extract column length for CHAR also. #7866 [ymendel]
Small additions and fixes for ActiveRecord documentation. Closes #7342 [jeremymcanally]
SQLite: binary escaping works with $KCODE=’u’. #7862 [tsuka]
Improved cloning performance by relying less on exception raising #8159 [Blaine]

root/tags/rel_1-2-4/actionpack/CHANGELOG 1.13.4 (October 4th, 2007)

Only accept session ids from cookies, prevents session fixation attacks. [bradediger]
Change the resource seperator from ; to / ## foos/1;edit ==> foos/1/edit
change the generated routes to use the new-style named routes. e.g. new_group_user_path(@group) instead of group_new_user_path(@group). [pixeltrix]
Integration tests: introduce methods for other HTTP methods. #6353 [caboose]
Improve performance of action caching. Closes #8231 [skaes]
Fix errors with around_filters which do not yield, restore 1.1 behaviour with after filters. Closes #8891 [skaes] After filters will no longer be run if an around_filter fails to yield, users relying on this behaviour are advised to put the code in question after a yield statement in an around filter.
Allow you to delete cookies with options. Closes #3685 [josh, Chris Wanstrath]
Deprecate pagination. Install the classic_pagination plugin (svn://errtheblog.com/svn/plugins/classic_pagination) for forward compatibility, or move to the superior will_paginate plugin (svn://errtheblog.com/svn/plugins/will_paginate). #8157 [Mislav Marohnic]
Fix filtered parameter logging with nil parameter values. #8422 [choonkeat]
Integration tests: alias xhr to xml_http_request and add a request_method argument instead of always using POST. #7124 [Nik Wakelin, Francois Beausoleil, Wizard]
Document caches_action. #5419 [Jarkko Laine]
observe_form always sends the serialized form. #5271 [manfred, normelton@gmail.com]
Update UrlWriter to accept :anchor parameter. Closes #6771. [octopod]
Replace the current block/continuation filter chain handling by an implementation based on a simple loop. Closes #8226 [Stefan Kaes]
Return the string representation from an Xml Builder when rendering a partial. #5044 [tpope]
Cleaned up, corrected, and mildly expanded ActionPack documentation. Closes #7190 [jeremymcanally]
Small collection of ActionController documentation cleanups. Closes #7319 [jeremymcanally]
Performance: patch cgi/session/pstore to require digest/md5 once rather than per #initialize. #7583 [Stefan Kaes]
Deprecation: verification with :redirect_to => :named_route shouldn’t be deprecated. #7525 [Justin French]

yield

2007-07-25T10:27:00.001+02:00

2. It's best to do one thing really, really well. (Rails refactoring with painless AOP)

2007-05-16T00:29:00.000+02:00

I like Google philosophy a lot, especially Thing Number 9 :

9. You can be serious without a suit.

, but that's not the subject of this sermon; today I'd like to tell you about Thing Number Two (TNT) :

2. It's best to do one thing really, really well.

- Amen -, and its IT translation : the "Separation Of Concerns". At the humble coder's level, separated concerns make for a more readable code. Counter example:

def fetch_stuff(*args)
  benchmark = Benchmark.measure{
    Stuff.fetch_all
  }
  puts "time spent: #{benchmark} "
end

It's ugly, but it works. It works, but it's ugly: this code does TWO completely unrelated things:

fetch some stuff, and
benchmark an action, any action

We MUST find a way to separate those 2 concerns: The first and main concern is obvious :

123	def fetch_stuff Stuff.fetch_all # <<--- CONCERN 1 end

The second concern is easy to code

def generic_benchmarking_method
  benchmark = Benchmark.measure
    action_to_measure   # <<--- (concern 1)       
  }
  puts "time spent : #{benchmark}}" # <<--- CONCERN 2
end

but it's difficult to connect to the first method, because :

users of concern 1 should not have to know about concern 2 => they will just call the first method
as the benchmarking action is completely independent from the action it measures, this action should be passed as a parameter in some way

The solution: piggy-back the benchmarking method on the fetching method, transparently. Q: how do you piggy back ? A: with Rails' alias_method_chain , and some "convention over configuration magic"** (** hint: it's all in the methods naming) Take a deep breath and watch the mystery unveil :

Before

def fetch_stuff(*args)
  benchmark = Benchmark.measure{
    Stuff.fetch_all
  }
  puts "time spent: #{benchmark} "
end

After

# concern 1: just do it.
def fetch_stuff
  Stuff.fetch_all
end

# concern 2: just benchmark it.
def fetch_stuff_with_benchmarking(*args)
  benchmark = Benchmark.measure{
  fetch_stuff_without_benchmarking(*args)
  }
  puts "time spent: #{benchmark} "
end

alias_method_chain :fetch_stuff, :benchmarking

That's it : alias_method_chain wrapped benchmarking around fetch_stuff. After line 14 has been parsed, calls to the original fetch_stuff are redirected to fetch_stuff_with_benchmarking, and fetch_stuff_without_benchmarking points to the original fetch_stuff. It's transparent and automatic. All you have to do is respect the naming convention : with and without. That's it. This method was introduced in Rails a year ago to DRY up the internals. There is no reason your code should not benefit shamelessly from it too. Strive for it. You'll thank me later. API :

http://caboo.se/doc/classes/Module.html#M003437

Articles :

http://weblog.rubyonrails.org/2006/4/26/new-in-rails-module-alias_method_chain

http://errtheblog.com/post/1109

Rails plugins : group_by(environment)

2007-05-13T00:17:00.000+02:00

If your vendor/plugins directory gets overcrowded and you use some test/development-specific plugins, here is a quick way to clean up your source tree :

Step 1: split the `vendor/plugins` directory

Create two directories : vendor/plugins-development and vendor/plugins-test, and move your plugins accordingly :

Step 2: tell Rails where to find the moved plugins

In config/environment/development.rb add this line:

123	config.plugin_paths.push('vendor/plugins-development' ).uniq!

, and in config/environment/test.rb add:

123	config.plugin_paths.push('vendor/plugins-test' ).uniq!

And that's it.

Rails refactoring with delegate(..)

2007-05-10T01:59:00.000+02:00

“When something is too hard it means that you’re not cheating enough.”

DHH Before:

class Cart
  def initialize
    @items    = []
  end

  def size   ;    @items.size    end
  def clear  ;    @items.clear   end
  def empty? ;    @items.empty?  end

  attr_reader :items
end

After

class Cart
  def initialize 
    @items    = []
  end

  delegate :clear, :empty?, :size, :to => :items

  attr_reader :items
end

What it does: When you call


  cart.size

, Rails delegates the size() method call to the items object and executes:


  cart.items.size

How it works: If you look at the source, you'll notice that Rails actually generates 3 methods equivalent to the code we have just removed (see 'Before'), and injects them in the class code. The behaviour does not change; it's just a shorter way to write this code. Should you want (be careful) to delegate ALL the unknown methods calls, you could write :

1234	# delegate unknown methods calls to @itemsdef method_missing(method, args, &block) @items.send method, args, &blockend

API doc : http://caboo.se/doc/classes/Module.html#M003442

<% cache_unless(params.include?('no_cache_please') , ... do %>

2007-05-03T23:36:00.000+02:00

Is adding fragments/actions caching worth it for your Rails application, on your server?

Adding caching to an application complexifies the code (and can be hard to test).
The caching efficiency (in req/sec) depends on many factors : RAM size, CPU power, HD speed, DB caches size, ... A spectacular improvement measured on an old sluggish staging server could be barely noticeable on a modern 4-core machine with 8GB of RAM and the fastest disk money can buy.

Is caching worth it for your application, on your server? It depends. For example, in the Vooruit project the staging server is an old fart with a slow HD and barely enough memory to run 1 Mongrel instance. This is the machine I used to hand-tune the fragment-caching code. I needed to confirm that caching was also improving significantly the performance on the production server. Tip:

disable remotely some/all caching on the production server through a parameter in the url:

http://example.com/foobar?no_cache_please

In the views you want to test :
---------------------------------

<% cache_unless(params.include?('no_cache_please') , :genre => params[:genre]) do%>
   ... the cached code (html and erb)
<% end %>      


In application_helper.rb :
--------------------------

  def cache_unless(condition, name = {}, &block)
    if condition then block.call; return end
    cache(name, &block)
  end

Now you can turn the caching on and off to measure the speed increase on any remote machine:

httperf --server production.example.com --uri /nl --num-conns 100
Reply rate [replies/s]: min 6.6 avg 6.8 max 7.0 stddev 0.3 (2 samples)
Reply rate [replies/s]: min 5.6 avg 6.6 max 7.2 stddev 0.9 (3 samples)


httperf --server production.example.com --uri /nl?no_cache --num-conns 100
Reply rate [replies/s]: min 7.0 avg 7.1 max 7.2 stddev 0.1 (2 samples)
Reply rate [replies/s]: min 3.2 avg 5.0 max 7.2 stddev 1.7 (4 samples)

Was caching worth it? In this case, barely. Updated:
Clarified that this article is mostly about fragments and actions caching.

Bugs have a life of their own

2007-05-01T18:24:00.000+02:00

I've never put any bug in my code. They all sneeked in, on their own, without my consent. Bugs have a life of their own. Bugs were born and normally live in Bugland. When they want to take some vacation, they visit their family that happens to live in your code base. Some like it so much abroad that they decide stay longer, or even become permanent resident (MS products).

The Vooruit Kunstcentrum : on Rails

2007-04-30T21:23:00.001+02:00

The Vooruit Kunstcentrum in Ghent (Belgium), Flanders' biggest art center, has got a brand new web site. And it's Web2.0-ish. A lot. It's only in Dutch at this moment, but the English version is on the conveyor belt. We launched on April 20Th 2007, after 3 months of intense development - 100% in Ruby On Rails - and too many sleepless nights. (Yes, I do sleep better now, thank you for asking).

What's in the box?

A art-program browser on steroids (/productions ) + an art-lovers community cocoon (/community ). OK. Let's have a look at the features.

You can :

just have a peek :

, read the headlines,

, find a concert in April, a podium event next week or a party on May 26Th

, buy tickets,

, follow the suggestions

subscribe to the "new concerts" feed,

see what's on the menu in series like the Courtisane Festival 2007 voor kortfilm, video en nieuwe media :

or just be lazy and follow tags:

Each production (concert, theater, ..)

gets its own mini-site with a presentation of the event, articles by the Vooruit editors or external writers, ...

..,and photos, audios and videos

plus:

gets its own community area where registered members (it could be you) can recommend, vote, post short comments, tips, reviews, send pictures,

For popular events, you can see who plans to attend, or attended:

The Community :

If you want to check the community pulse, go no further than the Community area : and

see who's the member of the week :

..or the latest 9 members

find out what members are talking about :

or the latest photos they posted :

That's all folks. We did our bit. Now it's your turn : create an account. , and we'll create a place just for you,

where you can tell us who you are, what you like:

, and upload your pictures :

, and publish your texts (Yes, you are an author)

A useful feature: all the events you ever tagged, rated, reviewed, or tipped

.. will show up in you 'Kalender' tab :

All the people you ever tagged as friends

.. will show up in your 'Friends' tab : And finally,

whenever you see an article, a text, an image, a video, an audio you like, just mark it :

and it will show up in you 'Favourites' tab :

The future of vooruit.be :

Following the great Google tradition, we launched in beta mode. Over the coming months, you can expect many more great features: an English version, groups, screencasts, individual users auto-blogs, and super-secret stuff I can't tell you about, (otherwise I'd have to kill you, and I don't want to do that anymore; who knows, you could become a client one day).

The Team :

As with most success stories, this project was a team effort. On the client side there was : * Eddy Naert the client voice, the graphist, the project manager and much more : if it looks good and it's useful, it's thanks to him. * A super great team of dedicated editors, who worked long hours, even on Sundays, to create the rich contents for you. If it's interesting, it's thanks to them. On the developer side, there was : * me (Alain Ravet), and Ruby on Rails: if it doesn't work, you know who to blame (hint: it's not 'Rails')