app['rds_database'][environment]['rds_name']

If I wanted to test if this value is set I couldn’t safely just say:

if app['rds_database'][environment]['rds_name']

because in some cases

if app['rds_database']

or

if app['rds_database'][environment]

may be nil .

If ether of those were nil and I execute

if app['rds_database'][environment]['rds_name']

I would get an exception like:

NoMethodError: undefined method `[]' for nil:NilClass

I have been doing something like:

if app['rds_database'] && app['rds_database'][environment] && app['rds_database'][environment]['rds_name']

But that was starting to make me sick to my stomach. I like my Ruby fine and DRY

So I scoured the Internet (well googled a bit) and found a couple of good Stack Overflow posts like How to access an element deep in an array of arrays without getting ‘undefined method’ error and Looking for a Good Way to Avoid Hash Conditionals in Ruby.

But most of them were ways to Monkey Patch the Hash Object or use new operators that are loaded by Gems.

One of them was pretty simple and was pretty DRY. Though some commentors called it an indiscriminate use of  rescue and EEEEVVVVIIILLLLL.

But it seems to me to be a very discriminate use of rescue, as any case where the rescue happens, I want it to return nil:

if (app['rds_database'][environment]['rds_name'] rescue nil)

The parenthesis aren’t needed, but I think it makes it clearer whats going on. Especially if you say something like:

return unless (app['rds_database'][environment]['rds_name'] rescue nil)

So I’m going to give that a try for a while.

The post Avoiding a series of tests with Ruby Hashes of Hashes that might have nil before the leaf hash first appeared on Cognizant Transmutation.

Right now, the most productive way to find cookbooks seems to be to search github. I always do a search before I write my own. Google searches are tough since “chef”, “cookbooks” are overloaded from the “real cooking” domain. And if you put in some package name, you tend to get announcements about the package and a mention about Opscode, but rarely about an Opscode Cookbook for that package.

Today I discovered that I needed a cookbook to install jruby. So after a useless Google Search. I did a search “jruby cookbook” on github and soon found Theo Cushion’s cookbook clone with a jruby addition.

Update 2/18/2012:

Looks like Theo Cushion’s github account no longer exists. Another jruby cookbook can be found Jorge Falcão at https://github.com/jlbfalcao/chef-jruby

Its better to not have to write it yourself! My thanks to Theo, Jorge  and the many others who share their code.

The post Nice jruby installation cookbook (Opscode) first appeared on Cognizant Transmutation.

There are other issues using this technique. To quote Flinn:

Achtung! Monkey patching with the above will expose your create method without using an actual post. Imho no big deal, others might be more cautious (CAPTCHAis always an option), ymmv.

See his original article for details on how to use it generally. 

The problem with the monkeypatch that he wrote up is that Rails 2.2.2 changed the function that was monkeypatched so the patch stopped working. Below is code that will work on both pre and post 2.2.2 Rails:

module ActionController
  class AbstractRequest

    def request_method

      if Rails::VERSION::STRING < "2.2.2"

        @request_method ||= begin

          method = (parameters[:_method].blank? ? @env['REQUEST_METHOD'] : parameters[:_method].to_s).downcase

          if ACCEPTED_HTTP_METHODS.include?(method)

            method.to_sym

          else

            raise UnknownHttpMethod, "#{method}, accepted HTTP methods are #{ACCEPTED_HTTP_METHODS.to_a.to_sentence}"

          end

        end

      else

        method = @env['REQUEST_METHOD']

        method = parameters[:_method] unless parameters[:_method].blank?

        HTTP_METHOD_LOOKUP[method] || raise(UnknownHttpMethod, "#{method}, accepted HTTP methods are #{HTTP_METHODS.to_sentence}")
      end

    end

  end
end
The post Cross Domain RESTful AJAX with jQuery and Rails 2.2.2 first appeared on Cognizant Transmutation.
]]>
					
					https://www.ibd.com/howto/cross-domain-restful-ajax-with-jquery-and-rails-222/feed/
			1
		
		
		156	
		
		
		https://www.ibd.com/ruby-rails/quarkruby-consume-non-rails-style-rest-apis/
		
		
		Wed, 31 Dec 2008 01:09:41 +0000
				
		
		
		
		http://blog2.ibd.com/?p=87

					It seems that most “RESTful” APIs in the wild are well, pretty wild. They don’t meet the strict requirements of the pure CRUD/REST of ActiveResource. The article in QuarkRuby:  Consume non rails-style REST APIs shows how to create a nice ruby wrapper around ActiveResource so you can adapt to any arbitrary REST / http interface on the Internet.

The post QuarkRuby: Consume non rails-style REST APIs first appeared on Cognizant Transmutation.
]]>
										It seems that most “RESTful” APIs in the wild are well, pretty wild. They don’t meet the strict requirements of the pure CRUD/REST of ActiveResource.

The article in QuarkRuby:  Consume non rails-style REST APIs shows how to create a nice ruby wrapper around ActiveResource so you can adapt to any arbitrary REST / http interface on the Internet.
The post QuarkRuby: Consume non rails-style REST APIs first appeared on Cognizant Transmutation.
]]>
					
		
		
		87