gistfile1.rb

def index
  
  @programs = @camp.programs.order('name')
  
  # some of these could be scoped out to make the controller cleaner if the queries are going to show up in other places
  # eg
  # scope :minage, lambda { |age| where(min_age >= ?, age) }
  # @programs = @programs.minage(params[:min_age]) if params[:min_age]
  @programs = @programs.where('min_age >= ?', params[:min_age]) if params[:min_age]
  @programs = @programs.where('max_age <= ?', params[:max_age]) if params[:max_age]
  @programs = @programs.where('min_price >= ?', params[:min_price]) if params[:min_price]
  @programs = @programs.where('max_price <= ?', params[:max_price]) if params[:max_price]
  @programs = @programs.joins(:sessions).where('sessions.start_date >= ?', params[:start_date].to_date) if params[:start_date]
  @programs = @programs.joins(:sessions).where('sessions.end_date <= ?', params[:end_date].to_date) if params[:end_date]
  @programs = @programs.send(params[:availablity].to_sym) if ['open', 'closed'].include?(params[:availablity])


  if @programs
    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @programs }
    end
  else
    respond_to do |format|
      format.html { render :action => "index", :status => :not_found }
      format.xml  { render :xml => @programs.errors, :status => :bad_request }
    end
  end
end

# you only need lambda in scopes if there's a variable inside the scope

# This is here so we don't repeat ourselves in the open/closed scopes
scope :availablity, joins(:program_populations).group("programs.id")

scope :open, where('program_populations.current_population < program_populations.max_population')
scope :closed, where('program_populations.current_population >= program_populations.max_population')