Rails - Mar 2006 - decorators for models?

Hi!

I''m thinking of implementing datagrid like functionality for showing 
data (models) in grids so that I don''t have to re-invent the 
view/controller for each table I need. There are number of parameters 
that need to be customizable: column titles, row style depending on the 
data (i.e. showing all rows with balance<0 in red), is column sortable, 
sort-algorithm etc.

To me, putting this parametrization in model like i.e. scaffold 
extension does (fields like @scaffold_fields, @scaffold_*) isn''t the 
right choice, as these parameters have more to do with "visual model" 
than with data model, so I was thinking of creating app/decorators/ and 
putting these visual models into separate classes (decorators) there 
i.e.

class OrdersDecorator < ActiveRecord::Decorator

The base class (AR::Decorator), each decorator would becom instance 
variable @model, which could be used to refer to original model, and 
this could happen automagically depending on the class name. There would 
be some default functions, like field_title that would return humanized 
column descriptions (i.e. order_status -> Order status)

This is how one such decorator could look like

class OrdersDecorator < ActiveRecord::Decorator
  @datagrid_fields=%w(id, name, country)

  def datagrid_field_title_id
    "Order ID"
  end

  def datagrid_row_style(m)
    ''big-order'' if m.total>100
  end

  def sort_country(a,b,direction)
   return a.continent<b.continet #sort countries by continent, not by 
name
  end
end

What do you think?

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

instead of using a decorator, why don''t you implement it as a module
and
then mix it into ActiveRecord::Base? That way, any existing model classes
you have will obtain the datagrid functionality.

On 3/7/06, Esad Hajdarevic <esad.nospam@esse.at>
wrote:
>
> Hi!
>
> I''m thinking of implementing datagrid like functionality for
showing
> data (models) in grids so that I don''t have to re-invent the
> view/controller for each table I need. There are number of parameters
> that need to be customizable: column titles, row style depending on the
> data (i.e. showing all rows with balance<0 in red), is column sortable,
> sort-algorithm etc.
>
> To me, putting this parametrization in model like i.e. scaffold
> extension does (fields like @scaffold_fields, @scaffold_*) isn''t
the
> right choice, as these parameters have more to do with "visual
model"
> than with data model, so I was thinking of creating app/decorators/ and
> putting these visual models into separate classes (decorators) there
> i.e.
>
> class OrdersDecorator < ActiveRecord::Decorator
>
> The base class (AR::Decorator), each decorator would becom instance
> variable @model, which could be used to refer to original model, and
> this could happen automagically depending on the class name. There would
> be some default functions, like field_title that would return humanized
> column descriptions (i.e. order_status -> Order status)
>
> This is how one such decorator could look like
>
> class OrdersDecorator < ActiveRecord::Decorator
>   @datagrid_fields=%w(id, name, country)
>
>   def datagrid_field_title_id
>     "Order ID"
>   end
>
>   def datagrid_row_style(m)
>     ''big-order'' if m.total>100
>   end
>
>   def sort_country(a,b,direction)
>    return a.continent<b.continet #sort countries by continent, not by
> name
>   end
> end
>
> What do you think?
>
> --
> 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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