gistfile1.txt

# Responsible for mapping a hash of parameters that will typically be POSTed to a controller into a hash that can be sent to find(:all) 
# containing SQL clauses in :conditions / :order.
# This helps us decouple the view / controller layers from any database specific stuff.
class Venue::QueryAdapter < Hash
  
  def initialize(params)

    parse params
    
    self.merge!(get_find_params)

  end
  
  private
  
  def parse(params)
    @sort_column = params[:sort]
    @city_id = params[:city_id]
    @name = params[:name]
    @page = params[:page]
  end

  def get_find_params
  
    find_params = {}
  
    find_params.merge!( :order      => get_order_clause ) if get_order_clause.length > 0
    find_params.merge!( :conditions => get_where_clause ) if get_where_clause.length > 0
    find_params.merge!( :page       => @page )
  
    return find_params
  
  end

  def get_where_clause
  
    clause = []
  
    clause << "city_id = #{@city_id}" if @city_id
    clause << "name like '%#{@name}%'" if @name
  
    return clause.join(" AND ")
  
  end

  def get_order_clause
  
    clause = []
  
    clause << 'created_on DESC' if @sort_column == 'created_at'
    clause << 'name ASC'
  
    return clause.join(", ")
  
  end
  
end