Rails - Jun 2005 - Association reflection?

Is there any support for finding out about AR associations
"reflectively"?
That is, dynamicaly by making some sort of call that that tells you what 
associations a given class might have?

Thanks.

On Jun 18, 2005, at 6:22 PM, David Corbin wrote:
> Is there any support for finding out about AR associations  
> "reflectively"?
> That is, dynamicaly by making some sort of call that that tells you  
> what
> associations a given class might have?
>
> Thanks.
Yes.  You can use  
ActiveRecord::Reflection::ClassMethods#reflect_on_all_associations.

See http://api.rubyonrails.com/classes/ActiveRecord/Reflection/ 
ClassMethods.html


Duane Johnson
(canadaduane)

On Sunday 19 June 2005 02:22, David Corbin wrote:
> Is there any support for finding out about AR associations
> "reflectively"? That is, dynamicaly by making some sort of call
that
> that tells you what associations a given class might have?
See reflect_on_all_associations and reflect_on_association

A drawback of those methods is that the association options they return, 
among other things, only contain what''s "unusual" about the 
association. IMHO that''s barely usable by itself and I''ve
wrapped a
utility method around this

def options_for_association(klass, association_name)
  if meta = klass.reflect_on_association(association_name.to_sym)
    options = meta.options
    options[:class_name] ||= Inflector.camelize(
      association_name.singularize)
    options[:foreign_key] ||= Inflector.foreign_key(
      association_name.singularize)
    options[:association_foreign_key] ||= Inflector.underscore(
      Inflector.demodulize(klass.name)) + ''_id''
    if block_given?
      yield options
    else
      options
    end
  end
end

I''m not completely sure if this completely correct in all cases, 
though...

Michael

-- 
Michael Schuerig                       Face reality and stare it down
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org        --Jethro Tull,
Silver River Turning
http://www.schuerig.de/michael/