From: Rick DeNatale <rick.denatale@...>
Date: 2009-04-02T01:09:09+09:00
Subject: Re: Anything better than klass = eval("#{task_class}")

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On Wed, Apr 1, 2009 at 10:47 AM, Rob Biedenharn
<Rob@agileconsultingllc.com>wrote:

> On Apr 1, 2009, at 9:32 AM, Gregory Brown wrote:
>
>  On Wed, Apr 1, 2009 at 9:14 AM, Paganoni <noway@fakenullvoid.com> wrote:
>>
>>> Hi, well subject is self explanatory...
>>>
>>> Seems a bit to verbose for me but I don't know any other solution to
>>> convert
>>> a string containing a class name to a constant of that class name...
>>> Excepted rails way : task_class.camelize.constantize which is verbose
>>> too...
>>>
>>
>>  Object.const_get("String")
>>>>
>>> => String
>>
>> -greg
>>
>> --
>> BOOK:  http://rubybestpractices.com
>> TECH: http://blog.majesticseacreature.com
>> NON-TECH: http://metametta.blogspot.com
>>
>
> Or dealing with things like Admin::User or Net::HTTP
>
>  # from Jim Weirich (based on email correspondence)
>  def constantize(camel_cased_word)
>    camel_cased_word.
>      sub(/^::/,'').
>      split("::").
>      inject(Object) { |scope, name| scope.const_get(name) }
>  end
>
> It may be more verbose, but it is much safer that plain 'ole eval()
>

Actually, I don't think this is entirely right, since const_get will find
constants found in outer scopes.

For example constantize("MyModule::Object") would return ::Object

So a little better would be:

 def constantize(camel_cased_word)
   camel_cased_word.
     sub(/^::/,'').
     split("::").
     inject(Object) { |scope, name| scope.const_defined?(name) ?
scope.const_get(name) : scope.const_missing(name) }
 end



-- 
Rick DeNatale

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