Do not hold AR class objects in callsites because class reloading in …

…dev mode will be hampered (fixes issue 4)

lib/slim_scrooge/callsite.rb

@@ -9,7 +9,7 @@ class Callsite
     ScroogeRegexJoin = /(?:LEFT|INNER|OUTER|CROSS)*\s*(?:STRAIGHT_JOIN|JOIN)/i
 
     attr_accessor :seen_columns
-    attr_reader :columns_hash, :primary_key, :model_class
+    attr_reader :columns_hash, :primary_key, :model_class_name
 
     class << self
       # Make a callsite if the query is of the right type for us to optimise
@@ -40,19 +40,19 @@ def select_regexp(table_name)
 
     def initialize(model_class)
       @all_columns = SimpleSet.new(model_class.column_names)
-      @model_class = model_class
+      @model_class_name = model_class.to_s
       @quoted_table_name = model_class.quoted_table_name
       @primary_key = model_class.primary_key
       @quoted_primary_key = model_class.connection.quote_column_name(@primary_key)
       @columns_hash = model_class.columns_hash
       @select_regexp = self.class.select_regexp(model_class.table_name)
-      @seen_columns = SimpleSet.new(essential_columns)
+      @seen_columns = SimpleSet.new(essential_columns(model_class))
     end
 
     # List of columns that should always be fetched no matter what
     #
-    def essential_columns
-      @model_class.reflect_on_all_associations.inject([@primary_key]) do |arr, assoc|
+    def essential_columns(model_class)
+      model_class.reflect_on_all_associations.inject([@primary_key]) do |arr, assoc|
         if assoc.options[:dependent] && assoc.macro == :belongs_to
           arr << assoc.association_foreign_key
         end
@@ -81,11 +81,15 @@ def reload_sql(primary_keys, fetched_columns)
       "SELECT #{cols} FROM #{@quoted_table_name} WHERE #{@quoted_primary_key} IN (#{sql_keys})"
     end
 
+    def connection
+      @model_class_name.constantize.connection
+    end
+
     # Change a set of columns into a correctly quoted comma separated list
     #
     def scrooge_select_sql(set)
       set.collect do |name|
-        "#{@quoted_table_name}.#{@model_class.connection.quote_column_name(name)}"
+        "#{@quoted_table_name}.#{connection.quote_column_name(name)}"
       end.join(ScroogeComma)
     end
   end

lib/slim_scrooge/result_set.rb

@@ -26,8 +26,7 @@ def reload!
       callsite = Callsites[@callsite_key]
       rows_hash = rows_by_key(callsite.primary_key)
       sql = callsite.reload_sql(rows_hash.keys, @fetched_columns)
-      model_class = callsite.model_class
-      new_rows = model_class.connection.send(:select, sql, "#{model_class.name} Reload SlimScrooged")
+      new_rows = callsite.connection.send(:select, sql, "#{callsite.model_class_name} Reload SlimScrooged")
       new_rows.each do |row|
         if old_row = rows_hash[row[callsite.primary_key]]
           old_row.result_set = nil

slim_scrooge.gemspec

@@ -5,11 +5,11 @@
 
 Gem::Specification.new do |s|
   s.name = %q{slim_scrooge}
-  s.version = "1.0.3"
+  s.version = "1.0.4"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
   s.authors = ["Stephen Sykes"]
-  s.date = %q{2009-11-26}
+  s.date = %q{2009-12-26}
   s.description = %q{Slim scrooge boosts speed in Rails ActiveRecord Models by only querying the database for what is needed.}
   s.email = %q{sdsykes@gmail.com}
   s.extensions = ["ext/extconf.rb"]