Rails : sort for the specific column

Look at this railscasts #228 http://railscasts.com/episodes/228-sortable-table-columns

def sortable(column, title = nil)
  title ||= column.titleize
  css_class = column == sort_column ? "current #{sort_direction}" : nil
  direction = column == sort_column && sort_direction == "asc" ? "desc" : "asc"
  link_to title, {:sort => column, :direction => direction}, {:class => css_class}
end

When you have functional sort columns, you then will need to save it to the db

A basic table with: user_id, page_name (or table_name), sort_column, sort_direction

Then when the user loads a page you would check against the saved settings and load them if they exist, if they don't you can load a default.

This is the idea, I do not have time to write the code for it, but it should be fairly straight forward.

Update:

Since I had to do this at work, I will post my code.

The railscast above implements the following three functions, which allow for sorting on a column.

application_controller.rb/or specific_controller.rb

def sort_column
  Product.column_names.include?(params[:sort]) ? params[:sort] : "name"
end

def sort_direction
  %w[asc desc].include?(params[:direction]) ? params[:direction] : "asc"
end

And the controller that uses it

def index
  @products = Product.order(sort_column + " " + sort_direction)
end

Now, in order to remember what the user selected for the sort and to use that instead of always loading the default sortable column we need to create a table for the user_preferences

create a migration for the preference table like

create_table :user_preferences do |t|
  t.string :action
  t.string :preference

  t.references :user
end
add_index :user_preferences, :user_id

When we search now (path -> 'specific_controller#index?direction=asc&sort=name') we need to save/update the user's preference

def index
  preference = UserPreference.find_by_user_id_and_action(User.current_user.id, params[:action])
  #Save/update preference based on column sort
  if params[:sort]
    unless preference.nil?
      preference.update_attribute(:preference, "#{params[:sort]},#{params[:direction]}")
    else
      preference = UserPreference.new(:user => User.current_user, :preference => "#{params[:sort]},#{params[:direction]}", :action => params[:action])
    end
  end
  populate_table_based_on_preference(preference)
end

def populate_table_based_on_preference(preference)
  unless preference.nil?
    @products = Product.order(preference.preference.split(',')[0]+ " " + preference.preference.split(',')[1])
  else
    @products = Product.order(sort_column + " " + sort_direction)
  end
end

Then we need to update our methods (sort_column/direction -> What column are we sorting/ Which direction? )

def sort_column
  #What are we sorting on?
  preference = UserPreference.find_by_user_id_and_action(User.current_user.id, params[:action])
  unless preference.nil?
    preference.preference.split(',')[0]
  else
    Product.column_names.include?(params[:sort]) ? params[:sort] : "name" 
  end
end

def sort_direction
  preference = UserPreference.find_by_user_id_and_action(User.current_user.id, params[:action])
  #what is the search direction
  unless preference.nil?
    preference.preference.split(',')[1]
  else
    %w[asc desc].include?(params[:direction]) ? params[:direction] : "asc" 
  end
end