From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2012-09-27T05:45:18+09:00
Subject: Re: Adding method on module class to yield and allow setting of attributes?

On Wed, Sep 26, 2012 at 10:41 PM, Gary Weaver <lists@ruby-forum.com> wrote:
> 7stud -- wrote in post #1077677:
>>> MyModule.configure do
>>>   foo = false
>>> end
>>
>> That just creates a block local variable which is destroyed when the
>> block ends.
>
> Is there a way to make things in the block execute as if they were being
> called on MyModule, i.e.
>
> MyModule.foo = 1
> MyModule.bar = 2
>
> could be alternatively:
>
> MyModule.do
>   foo = 1
>   bar = 2
> end
>
>> You could do this:
>>
>>
>> module MyModule
>>   class <<self
>>     attr_accessor :foo
>>
>>     def configure(hash)
>>       hash.each {|key, val| send(:"#{key}=", val)}
>>     end
>>   end
>>
>> end
>>
>> p MyModule.foo
>> MyModule.configure 'foo' => false
>> p MyModule.foo
>>
>> --output:--
>> nil
>> false
>
> That is helpful, but I have a way to do a hash easily already via
> another method, with the idea that the following might be interesting:
>
> MyModule.do
>   foo = 1
>   def bar
>     2 # imagine a more interesting and dynamic result
>   end
> end
>
> I understand it might require some changes, so syntax might not be
> exactly like that, but originally I thought this would be doable, and am
> just kind of stuck. Ilia had suggested ActiveSupport::Configurable on
> the list but it requires config to be sent in as a parameter and I was
> hoping to allow method definition and not have to specify the
> config.varname = ...

I don't know if my previous message got through. If you can handle
some changes in the syntax, using self. before the attributes and the
method names should work if you do a class_eval:

1.9.2p290 :013 > module MyModule
1.9.2p290 :014?>     class << self
1.9.2p290 :015?>         attr_accessor :foo
1.9.2p290 :016?>     alias_method :foo?, :foo
1.9.2p290 :017?>     def configure(&blk)
1.9.2p290 :018?>       class_eval(&blk)
1.9.2p290 :019?>       end
1.9.2p290 :020?>     end
1.9.2p290 :021?>   end
 => nil
1.9.2p290 :022 > MyModule.configure do
1.9.2p290 :023 >     def self.test; puts "test"; end
1.9.2p290 :024?>   end
 => nil
1.9.2p290 :025 > MyModule.test
test
 => nil



Jesus.