Rails - Jun 2006 - share model definition

I want to share everything about a model except the db connection.  Is 
this a reasonable way to do it?

module NotebookDefinition

-- 
Posted via http://www.ruby-forum.com/.

Dan Kirkwood wrote:
> I want to share everything about a model except the db connection.  Is 
> this a reasonable way to do it?
>
> module NotebookDefinition
>
>   
Please expound on ''share''. Are we talking subclassing? If so,
any model
can redefine the AR''s connection, and all of that class will use the
same connection. Otherwise I''m not sure what you''re hinting
at.

Jason

IF everything is the same except for the dbconnection, you could just
specify the dbconnection you want in each model, or put that in a module
that you include.
>From a plugin of mine where the model and the database.yml file are in the
same folder:

class PersonRecord << ActiveRecord::Base

    c = YAML::load(File.open(File.dirname(__FILE__) +
"/person_database.yml"))

    PersonRecord.establish_connection(
      :adapter=>c[RAILS_ENV][''adapter''],
      :host=>c[RAILS_ENV][''host''],
      :username=>c[RAILS_ENV][''username''],
      :password=>c[RAILS_ENV][''password''],
      :database=>c[RAILS_ENV][''database'']
    )

end

You could use modules to put the common code into multiple classes, but you
could also make a new base class and put the common code in that

class MyBase < ActiveRecord::Base
    def foo
       "bar''
    end
end

class User < MyBase
   has_many :projects
    c = YAML::load(File.open(File.dirname(__FILE__) +
"/user_database.yml"))

    User.establish_connection(
      :adapter=>c[RAILS_ENV][''adapter''],
      :host=>c[RAILS_ENV][''host''],
      :username=>c[RAILS_ENV][''username''],
      :password=>c[RAILS_ENV][''password''],
      :database=>c[RAILS_ENV][''database'']
    )

end

Would that work?



On 6/19/06, Dan Kirkwood <dangogh@gmail.com>
wrote:
>
> I want to share everything about a model except the db connection.  Is
> this a reasonable way to do it?
>
> module NotebookDefinition
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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sorry.. fat-fingered..  I want to share a common definition for each of 
the classes, but have all classes within a given module be able to 
operate on a separate database from other modules..

module NoteBookDefinition
  def import_definition
    set_table_name :notebooks
    has_many :pages
  end
end

class Master::Notebook
  extend NotebookDefinition
  import_definition
end

class Other::Notebook
  extend NotebookDefinition
  import_definition
  establish_connection :otherdb
end

module PageDefinition
  def import_definition
    belongs_to :notebook
  end
end

class Master::Page
  extend PageDefinition
  import_definition
end

class Other::Page
  extend PageDefinition
  import_definition
  establish_connection :otherdb
end

n = Master::Notebook.find :first
n.class   (returns Master::Notebook)
n.pages[0].class  (returns Master::Page)

m = Other::Notebook.find :first
m.class    (returns Other::Notebook)
m.pages[0].class  (returns Other::Page)



-- 
Posted via http://www.ruby-forum.com/.

Thanks for the suggestion, Brian..  If I specify the dbconnection in 
each model, then I''d have to repeat the entire model definition..  The 
question is, how to best share everything *except* the dbconnection.. 
It took a while to come up with the above scheme to share the rest 
(relationships, validations, etc)  Is that the best way to do it? 
-dan


Brian Hogan wrote:
> IF everything is the same except for the dbconnection, you could just
> specify the dbconnection you want in each model, or put that in a module
> that you include.
>>From a plugin of mine where the model and the database.yml file are in
the
> same folder:
> 
> class PersonRecord << ActiveRecord::Base
> 
>     c = YAML::load(File.open(File.dirname(__FILE__) +
> "/person_database.yml"))
> 
>     PersonRecord.establish_connection(
>       :adapter=>c[RAILS_ENV][''adapter''],
>       :host=>c[RAILS_ENV][''host''],
>       :username=>c[RAILS_ENV][''username''],
>       :password=>c[RAILS_ENV][''password''],
>       :database=>c[RAILS_ENV][''database'']
>     )
> 
> end
> 
> You could use modules to put the common code into multiple classes, but 
> you
> could also make a new base class and put the common code in that
> 
> class MyBase < ActiveRecord::Base
>     def foo
>        "bar''
>     end
> end
> 
> class User < MyBase
>    has_many :projects
>     c = YAML::load(File.open(File.dirname(__FILE__) + 
> "/user_database.yml"))
> 
>     User.establish_connection(
>       :adapter=>c[RAILS_ENV][''adapter''],
>       :host=>c[RAILS_ENV][''host''],
>       :username=>c[RAILS_ENV][''username''],
>       :password=>c[RAILS_ENV][''password''],
>       :database=>c[RAILS_ENV][''database'']
>     )
> 
> end
> 
> Would that work?

-- 
Posted via http://www.ruby-forum.com/.