```ruby
class OutputElementsController < ApplicationController
  layout false

  before_filter :find_output_element, :only => [:show, :zoom]

  # Returns all the data required to show a chart.
  # JSON only
  def show
    template = if tmpl = @chart.template
      render_to_string(:partial => tmpl, :locals => {:output_element => @chart})
    else
     nil
   end
    render :status => :ok, :json => {
      :attributes => @chart.json_attributes,
      :series => @chart.allowed_output_element_series.map(&:json_attributes),
      :html => template
    }
  end

  def index
    # id of the element the chart will be placed in
    @chart_holder = params[:holder]
    @groups = {}
    %w[Overview Policy Supply Demand Cost Merit FCE].each do |group|
      @groups[group] = OutputElement.not_hidden.
        select_by_group(group).
        sort_by{|c| t "output_elements.#{c.key}"}.
        reject(&:block_chart?).
        reject(&:not_allowed_in_this_area)
    end
  end

  # legacy actions used by the block charts
  #
  def invisible
    session[params[:id]] = 'invisible'
    render :js => ""
  end

  def visible
    session[params[:id]] = 'visible'
    render :js => ""
  end

  def zoom
  end

  private

  def find_output_element
    @as_table = params[:format] == 'table'
    @chart = OutputElement.find(params[:id])
  end
end
```

Hide charts with an unsatisfied area dependency
user
```ruby
class OutputElementsController < ApplicationController
  layout false

  before_filter :find_output_element, :only => [:show, :zoom]

  # Returns all the data required to show a chart.
  # JSON only
  def show
    template = if tmpl = @chart.template
      render_to_string(:partial => tmpl, :locals => {:output_element => @chart})
    else
     nil
   end
    render :status => :ok, :json => {
      :attributes => @chart.json_attributes,
      :series => @chart.allowed_output_element_series.map(&:json_attributes),
      :html => template
    }
  end

  def index
    # id of the element the chart will be placed in
    @chart_holder = params[:holder]
    @groups = {}
    %w[Overview Policy Supply Demand Cost Merit FCE].each do |group|
      @groups[group] = OutputElement.not_hidden.
        select_by_group(group).
        sort_by{|c| t "output_elements.#{c.key}"}.
        reject(&:area_dependent).
        reject(&:block_chart?).
        reject(&:not_allowed_in_this_area)
    end
  end

  # legacy actions used by the block charts
  #
  def invisible
    session[params[:id]] = 'invisible'
    render :js => ""
  end

  def visible
    session[params[:id]] = 'visible'
    render :js => ""
  end

  def zoom
  end

  private

  def find_output_element
    @as_table = params[:format] == 'table'
    @chart = OutputElement.find(params[:id])
  end
end
```
assistant