application_helper.rb

  def get_site_id
    (get_site && get_site.id) || '0'
  end
  
  def get_site_name
    get_site.name
  end
  
  def get_site_code
    params[:site_code]
  end
  
  def get_site_path
    "/sites/" + get_site_code
  end

  def get_site
    @current_site ||= Site.find_by_site_code(params[:site_code])
  end

general_helpers.rb

  def site
    @current_site ||= Site.find_by_site_code(params[:site_code])
  end
  
  def site_path
    "/sites/" + params[:site_code]
  end

general_helpers_spec.rb

  describe '#site' do
    it 'should return the site we have stored in @current_site' do
      @current_site = Site.should_not_receive(:find_by_site_code)
      @it.site.should eql(@current_site)
    end
    
    it 'should return the site based on the params[:site_code] if @current_site is not set' do
      @it.site.should eql(nil)
      @it.stub!(:params).and_return(:site_code => 'some_site')
      Site.stub!(:find_by_site_code).with(params[:site_code]).and_return(@mysite)
      @it.site.should eql(@mysite)
    end
  end
  
  describe '#site_path' do
    it 'should return the correct site_path' do
      @it.stub!(:params).and_return(:site_code => 'some_site')
      @it.site_path.should eql('/sites/some_site')
    end
  end