Rails - Jul 2006 - can someone explain RoR MVC from a C++ or Java perspective?

is a model similiar to a class? and active record is similiar to how 
Java classes inherit from Object?

View is nothing more than an output of a model with HTML?

Controller is basically the Main part of the program?

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

Yes, model is just a class. It is the domain object. Active record gives you the
ORM functionality
to your model classes. You just extend your model class from ActiveRecord class.

View is similar to jsp pages. It has a template that can be .rhtml with ruby
code embedded in
html. Think of Controller class as the Action class in Struts. Welcome to the
wonderful
wonderland!!!

--- bbqDude <none@none.com> wrote:
> is a model similiar to a class? and active record is similiar to how 
> Java classes inherit from Object?
> 
> View is nothing more than an output of a model with HTML?
> 
> Controller is basically the Main part of the program?
> 
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

bbqDude wrote:
> is a model similiar to a class? and active record is similiar to how 
> Java classes inherit from Object?
> 
> View is nothing more than an output of a model with HTML?
> 
> Controller is basically the Main part of the program?
Controllers and models are all Classes, and every instance of any object 
inherits form class Object in Ruby.

Controller:
Handles requests and glues Models and Views together.  When a request 
comes in the controller has two responsibilities.  Change the state of 
models, if necesary, and retrieve data that the view will need. 
"actions" each have a unique url, and each action is a public method
of
a particular controller object.  So for controller People and the urls 
"/people", "people/show/1", "people/edit/1" the
controller would have
the public methods index, show, and edit.

The more code that can be put in the model, rather than the controller, 
the better. For example:

  #Bad:
  def charge_order
    order = Order.find(params[:id])
    result = CreditAPI.charge(1234123412341234, 9.99)
    if result.success?
      order.staus = :charged
      order.save
    end
  end

  #Good:
  def charge_order
    Order.find(params[:id])
    order.charge!(1234123412341234, 9.99)
  end


Model:
Wraps a particular database table, each column in the database gets an 
attribute reader/writer so you can do "@post.title =
''foo''" and whatnot.
A model may also be a Class that does not inherit form ActiveRecord, 
such as a ShoppingCart which simply exists in the session until an order 
is saved.

View:
Renders HTML (or RJS, or XML, etc.) based on the instance variable 
defined in the controller action that processed the request.  For 
instance, in the controller:

  class BlogController < ApplicationController
    def index
      @posts = Post.find(:all)
    end
  end

And say you wanted a list of the titles of all the posts.  You would 
have a view files called /app/views/blog/index.rhtml with the following:

  <ul>
    <% for post in @posts %>
      <li><%= post.title %></li>
    <% end %>
  </ul>

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

Hello Alex,
Thanks for an awesome explanation! I was just having trouble on what
belongs in a model vs in a controller. Thanks for putting things in
perspective!


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

you said put as much as you can in the model, why is this? and where is the
demarkation in your controller actions that should be split into the model
and controller, i.e what is the rule of thumb for putting actions in the
model?

  #Bad:
 def charge_order
   order = Order.find(params[:id])
   result = CreditAPI.charge(1234123412341234, 9.99)
   if result.success?
     order.staus = :charged
     order.save
   end
 end

 #Good:
 def charge_order
   Order.find(params[:id])
   order.charge!(1234123412341234, 9.99)
 end

On 8/1/06, Alex Wayne <rubyonrails@beautifulpixel.com>
wrote:
>
> bbqDude wrote:
> > is a model similiar to a class? and active record is similiar to how
> > Java classes inherit from Object?
> >
> > View is nothing more than an output of a model with HTML?
> >
> > Controller is basically the Main part of the program?
>
> Controllers and models are all Classes, and every instance of any object
> inherits form class Object in Ruby.
>
> Controller:
> Handles requests and glues Models and Views together.  When a request
> comes in the controller has two responsibilities.  Change the state of
> models, if necesary, and retrieve data that the view will need.
> "actions" each have a unique url, and each action is a public
method of
> a particular controller object.  So for controller People and the urls
> "/people", "people/show/1", "people/edit/1"
the controller would have
> the public methods index, show, and edit.
>
> The more code that can be put in the model, rather than the controller,
> the better. For example:
>
>   #Bad:
>   def charge_order
>     order = Order.find(params[:id])
>     result = CreditAPI.charge(1234123412341234, 9.99)
>     if result.success?
>       order.staus = :charged
>       order.save
>     end
>   end
>
>   #Good:
>   def charge_order
>     Order.find(params[:id])
>     order.charge!(1234123412341234, 9.99)
>   end
>
>
> Model:
> Wraps a particular database table, each column in the database gets an
> attribute reader/writer so you can do "@post.title =
''foo''" and whatnot.
> A model may also be a Class that does not inherit form ActiveRecord,
> such as a ShoppingCart which simply exists in the session until an order
> is saved.
>
> View:
> Renders HTML (or RJS, or XML, etc.) based on the instance variable
> defined in the controller action that processed the request.  For
> instance, in the controller:
>
>   class BlogController < ApplicationController
>     def index
>       @posts = Post.find(:all)
>     end
>   end
>
> And say you wanted a list of the titles of all the posts.  You would
> have a view files called /app/views/blog/index.rhtml with the following:
>
>   <ul>
>     <% for post in @posts %>
>       <li><%= post.title %></li>
>     <% end %>
>   </ul>
>
> --
> 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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On 7/31/06, bbqDude <none@none.com> wrote:
> Hello Alex,
> Thanks for an awesome explanation! I was just having trouble on what
> belongs in a model vs in a controller. Thanks for putting things in
> perspective!
It would probably help to read up about the MVC design pattern in
either of the books /Head First Design Patterns/ or /Design Patterns/.
 First explains the pattern in Java, and the other one explains the
pattern in C++ (I think).

Joe