Self.module_eval?

ruby-talk
1

Why does this work:

class ComplexObject
    attr_accessor :colour
    def initialize # :yield: c
        ComplexObject.module_eval "undef_method :colour="
    end
end

But this doesn't?

class ComplexObject
    attr_accessor :colour
    def initialize # :yield: c
        self.module_eval "undef_method :colour="
    end
end

(btw, I know about attr_reader, I'm just looking for ways around the
"disadvantages" for "Initializing complex objects" at
http://www.rubygarden.org/ruby?RubyIdioms )

I assumed that self == ComplexObject, but obviously not... why is that?

Cheers,
Douglas

2

When initialize() gets called, "self" will be setup to point to the current object, as is always true with Ruby instance methods. If you want to fetch the object's class, without hardcoding it, use "self.class..."

Hope that helps.

James Edward Gray II

···

On Apr 3, 2005, at 4:33 PM, Douglas Livingstone wrote:

Why does this work:

class ComplexObject
    attr_accessor :colour
    def initialize # :yield: c
        ComplexObject.module_eval "undef_method :colour="
    end
end

But this doesn't?

class ComplexObject
    attr_accessor :colour
    def initialize # :yield: c
        self.module_eval "undef_method :colour="
    end
end

(btw, I know about attr_reader, I'm just looking for ways around the
"disadvantages" for "Initializing complex objects" at
http://www.rubygarden.org/ruby?RubyIdioms )

I assumed that self == ComplexObject, but obviously not... why is that?