Posted by the guys at RailsEnvy.com for a talk they gave at Ruby Hoedown. http://www.railsenvy.com/assets/2008/8/8/RubyInnovation.pdf

Some interesting things that I did not know about.

I often get asked and see forum/blog post asking this question (or some variation of it):

"What do I need in order to start Ruby on Rails development?"

The following may not apply to all. But, face it. Admit it. There can be only one way. So, just follow this simple step to more joy and bliss. Here is the step to take. Yes, there is only one step.

Grow some balls

"But, but, but . . . those are my budz, my free time, my weekends . . . wha, wha, whahaaa".

So, tell me about your balls growthage

"But, that's easy for you to say. I am in (insert some worthless excuse here) . . . blah, blah, blabbity, blah, blah . . ."

What's the technology that you left behind?

What to read

• Getting Real


• The Ten Faces or Innovation


• Beyond Java


• From Java to Ruby


• Extreme Programming


• Rails Way


• Ruby Way


• Web Standards Solutions

• RailsCasts


• Rails Envy

It's not code, it's passion

I hate how slow TextMate is when searching in a project. Well, it turns out that it is not really because TextMate's search is slow. It might be. Most likely, the real problem is that, by default, TextMate is searching through ALL your Rails files. ALL, as in logs, vendor/rails, and so forth. This is what is slowing things down.

I don't take any credit for this. This is a tip from Dr. Nic on a TextMate Google Groups thread. But, I will distill it down for you.

Copy this crazy looking piece of regex (at least . . . I think it is regex):

!.*/(\.[^/]*|vendor/rails|doc|rails_root|CVS|log|data_dump|build|_darcs|pkg |_MTN|\{arch\}|blib|.*~\.nib|.*\.(framework|app|pbproj|pbxproj|xcode(proj)? |bundle))$

I can use Yum. But, I am going to install from source in order to get the latest builds.

libevent

wget http://monkey.org/~provos/libevent-1.4.6-stable.tar.gz
tar zxpfv libevent*
cd libevent*
./configure
make 
sudo make install

memcached

wget http://www.danga.com/memcached/dist/memcached-1.2.6.tar.gz
tar zxpfv memcached*
cd memcached*
./configure
make install

Errors . . . there is always at least one

error while loading shared libraries: libevent-*: cannot open shared object file: No such file or directory

sudo ln -s /usr/local/lib/libevent-1.4.so.2 /usr/lib

Start memcached

memcached -d -m 64 -p 11211

Connect to it from Rails 2.1

config.cache_store = :mem_cache_store, 'IP_ADDRESS_OF_MEMCACHED_SERVER:11211'

Without getting into real detail, I need this behavior because of a legacy database (Actually, it is not all that "legacy". It is more "enterprise-esque".).

Anyway . . .

Question: Can an ActiveRecord object invoke an instance method, then, while executing that method, destroy itself?

Code example:

@some_object.some_method

Class SomeObject < ActiveRecord::Base
  def some_method
    ...Some really awesome stuff happens here...
    self.destroy
  end
end

@some_object.some_method

Class SomeObject < ActiveRecord::Base
  def some_method
    ...Some really awesome stuff happens here...
    SomeObject.find(self).destroy
  end
end

This is pretty sweet.

Rails strictly adheres to the MVC model . . . which is good. Where Rails falls a little bit short is when a view needs to manipulate multiple models. The out of the box Rails behavior is one model to one controller to one view.

But, in practice, you often have views that manipulate multiple models. Thankfully, because Rails is flexible, you can accomplish this in a number of ways. However, it often leads to inconsistent code structure, and fat controllers, or nearly untestable code.

What we needed was a “pattern”. I had heard about the presenter pattern last year at RailsEdge in Chicago. At the time, it was just a concept. I didn’t really get it.

Looking at this post (ActivePresenter), I get it now. And, its implementation is pure elegance. I can't wait to try it out.