For example, ActiveMessaging uses several config files - some are yaml, some are ruby - all of them get loaded when the plugin gets initialized. ActiveMessaging has more than a bit of configuration, so distinct files for it makes sense. Also, it has less singular values that get set, and more sets of configuration values (e.g. all the values for a message broker connection).

Comatose uses a singleton with attributes that get defined in a block - so like the Rails initializer, you can call this define method in an environment.rb. Again, this makes sense, there are only a few values to fiddle with, and you very often don’t have to mess with them at all.

Not sure if I’ll use it, but I’ve been playing with an idea where you can use constants to override config values using constants. Makes sense for a plugin where you have default values that would rarely, and often individually, be overridden. Nice thing about this is that constants can be defined even before the config class, so if you need them to be set before the plugin is loaded, this provides a way.

Anyway, to make it easier, I wrote a little helper method to define class attributes, set the default value, and check for constants to override the default, all at one time.


class Config
 
  class <<self
    def set_config_value(var_sym, default=nil)
      cattr_accessor var_sym
      const_name = var_sym.to_s.upcase
      value = (Object.constants.include?(const_name)) ? Object.const_get(const_name): default
      class_variable_set("@@#{var_sym}".intern, value)
    end
  end
 
  # SOME_CONFIG_VALUE set as a constant will override the default
  set_config_value :some_config_value, "this is a default"
 
end


PRX has been around just long enough that now is good time to reassess strategy. That seems to be happening. But a few things are already clear: PRX is public radio’s fourth network; it’s the open source public radio network, and for those of us who are beginning to look for fresh, new voices to add to our schedules, it’s the best place to start.

I still need to spend some time making it prettier, adding images and such things, but most importantly it now has the list of events, and the online registration form which integrates with PayPal (Website Payments Standard in conjuntion with IPN). I am not a big PHP fan, but I do like being able to package up and deploy my new ‘pprf’ (PayPal Registration Form) plug-in to any WordPress site for testing. I need to make it a bit more generic, and add one more admin page, but hey, it works and I’ll probably release it as open source soon.

I’m mostly happy with the logo, as IANAD(esigner) - anything that comes from Illustrator out of my computer should be suspect, but I think the logo looks good.

Now on with the day, and hoping a get some rest before Tapestry classes kick my butt.

Lesson learned - Array.insert should probably be named Array.insert! - it changes the underlying array, and sometimes that’s not what you mean to do.

http://dev.rubyonrails.org/ticket/8383

Now we’ll see if it gets committed.

What we really want to do is use EC2 - look at the gigavox success story on amazon’s site - we need almost the same things, and want to implement almost the same arch - except using rails and activemessaging.

The problem is the EC2 closed beta - ugh - we’ve been waiting, oh so impatiently. In the meantime everyone shuold go get their feet wet with RightScale. You get 10 hours to play with, even without your own EC2 keys.

At PRX we wanted to be able to upload/resize/attach images and files, have a preview mode to see what the home page would look like before we publish parts of the content, and also we wanted to be able to access session info so we could make some content vary based on info in a user’s session (this is also part of how the ‘preview’ mode works).

Folks on the forums also seem to be trying to figure this kind of thing out, so I humbly offer what I have gotten to work.

So without exposing all the work I am cleaning up on extending comatose, here is a bit of code showing how to add the session info to the comatose pages so it can be accessed and used.

As for the rest of my enhancements - well, I need to make it into a plugin I think, that gets installed on top of comatose. That will have to wait, as I am too busy adding enhancements at the moment to stop and package it….

read more | digg story

Have a look, there’s also a very short prez I gave at the IMA 2007 Conference showing how we use S3, ActiveMq, Rails, ActiveMessaging and other junk like that to make our systems hum.

Here it is again: