gistfile1.rb

# Here is a neat little named scope module that let's me easily abstract out making finders based on 
# class column names. The nice thing is that it does quite a few chores. First it makes sure that passed 
# in column names exist in the schema. Second, it escapes values while building the string.

module NamedScopes
  
  module AttributeScopes
    
    def self.included(base)
      base.class_eval do
        extend ClassMethods
        named_scope :attribute_like,  lambda { |column,query| {:conditions => attribute_like_string(column,query)} }
        named_scope :attributes_like, lambda { |query,*columns| {:conditions => attributes_like_string(query,*columns)} }
      end
    end
    
    module ClassMethods
      
      def attribute_like_string(column,query)
        return nil if query.blank? || !self.column_names.include?(column.to_s)
        escaped_query = self.connection.quote_string(query.strip)
        escaped_column = self.connection.quote_column_name(column)
        "#{escaped_column} LIKE '%#{escaped_query}%'"
      end
      
      def attributes_like_string(query,*columns)
        columns.map do |column|
          attribute_like_string(column,query)
        end.compact.join(' AND ')
      end
      
    end
    
  end
  
end


class Listing < ActiveRecord::Base
  
  include NamedScopes::AttributeScopes
  
  class << self
    
    def find_or_create_with_attributes(attrs={})
      find_by_like_key_and_org_name(attrs[:address_key],attrs[:organization_legal_name]) ||
        find_by_like_key_and_contact_name(attrs[:address_key],attrs[:contact_name]) || 
        create(attrs) do |listing|
          # Configure listing here if attrs mass assignment protects.
        end
    end
    
    protected
    
    def find_by_like_key_and_org_name(key,name)
      return nil if [key,name].any?(&:blank)
      attribute_like(:address_key,key).attribute_like(:organization_legal_name,name).first
    end
    
    def find_by_like_key_and_contact_name(key,name)
      return nil if [key,name].any?(&:blank)
      attribute_like(:address_key,key).attribute_like(:contact_name,name).first
    end
    
  end
  
end