Can you set Base class attributes from a subclass?

Rails
1

Hello,
I’m overriding the initialize method of a base class and I’m trying
to set a Base class variable in the overridden method and have it
register in the Base class (hope that makes sense).

Here’s my code:


in Rails::Generator::Base:


class Base
  include Options
  class_inheritable_accessor :spec

  def initialize(runtime_args, runtime_options = {})
    @args = runtime_args
    parse!(@args, runtime_options)

    # Derive source and destination paths.
    @source_root = options[:source] || File.join(spec.path, 'templates')
  end
end

class MediaModuleGenerator < Rails::Generator::Base
  def initialize(runtime_args, runtime_options = {})
     self.spec.path = File.dirname(__FILE__) +
'/generators/media_module'
     super
  end
end

I should mention that spec is a module w/in the Rails framework IE:
Rails::Generator::Spec

When I run my generator, I get this error:

You have a nil object when you didn’t expect it! (NoMethodError) The
error occurred while evaluating nil.path

So when I set the self.spec.path var to File.dirname(FILE) +
‘/generators/media_module’, it’s not registering in the base class.

Any ideas?

2

On Wed, Jun 3, 2009 at 7:39 PM, Clem R.
[email protected]wrote:

in Rails::Generator::Base:

Derive source and destination paths.

end

If you’re overriding the initialize method, then you should be
calling super before any other expression. This isn’t necessary
in regards to subclasses who parent is Object.

-Conrad

3

On Wed, Jun 3, 2009 at 7:58 PM, Conrad T. [email protected]
wrote:

@args = runtime_args
‘/generators/media_module’
super
end
end

If you’re overriding the initialize method, then you should be
calling super before any other expression. This isn’t necessary
in regards to subclasses who parent is Object.

You should have an expression like this in your subclass:

super( runtime_args, runtime_options )

If you need further details, please consult the PixAxe book.

-Conrad

4

On Wed, Jun 3, 2009 at 9:08 PM, Clem R.
[email protected]wrote:

my overidden initialize method now looks like this:

wrote:

calling super before any other expression. This isn’t necessary

What’s on line 107 that’s generating the error message?

-Conrad

5

I tried adding

super( runtime_args, runtime_options )

and still got this error:

rails_generator/base.rb:107:in `initialize’: You have a nil object when
you didn’t expect it!

my overidden initialize method now looks like this:

def initialize(runtime_args, runtime_options = {})
super( runtime_args, runtime_options )
end

Conrad T. wrote:

On Wed, Jun 3, 2009 at 7:58 PM, Conrad T. [email protected]
wrote:

@args = runtime_args
‘/generators/media_module’
super
end
end

If you’re overriding the initialize method, then you should be
calling super before any other expression. This isn’t necessary
in regards to subclasses who parent is Object.

You should have an expression like this in your subclass:

super( runtime_args, runtime_options )

If you need further details, please consult the PixAxe book.

-Conrad

6

this is line 107:

@source_root = options[:source] || File.join(spec.path, ‘templates’)

Conrad T. wrote:

On Wed, Jun 3, 2009 at 9:08 PM, Clem R.
[email protected]wrote:

my overidden initialize method now looks like this:

wrote:

calling super before any other expression. This isn’t necessary

What’s on line 107 that’s generating the error message?

-Conrad

7

spec.path is nil.path - that’s the whole problem - I’m trying to set the
spec.path = File.dirname(FILE) + ‘/generators/media_module’ in my
overidden initialize method and I can’t seem to send that value to the
Base class.

Conrad T. wrote:

What’s the value of spec.path?

On Wed, Jun 3, 2009 at 10:38 PM, Clem R.
<[email protected]

8

What’s the value of spec.path?

On Wed, Jun 3, 2009 at 10:38 PM, Clem R.
<[email protected]