single.rb in db_mod-0.0.5

- old
+ new
@@ -8,55 +8,49 @@
   module Statements
     module Configuration
       # Provides convenience extensions for statement and
       # prepared methods that return only a single result,
       # row, or column. The normal way to access this functionality
-      # is via {ConfigurableMethod#single}, which is available
+      # is via {MethodConfiguration#single}, which is available
       # when defining a statement method or prepared method:
       #
-      #  def_statement(:a, 'SELECT name FROM a WHERE id=$1').single(:value)
-      #  def_prepared(:b, 'SELECT id FROM b WHERE value > $min').single(:column)
-      #  def_prepared(:c, 'SELECT * FROM c WHERE id = $id').single(:row)
+      #  def_statement(:a, 'SELECT name FROM a WHERE id=$1') { single(:value) }
+      #  def_prepared(:b, 'SELECT id FROM b WHERE x > $y') { single(:column) }
+      #  def_prepared(:c, 'SELECT * FROM c WHERE id = $id') { single(:row) }
       #
       #  def do_stuff
-      #    a # => "foo"
-      #    b # => ['1','2','3',...]
-      #    c # => Hash
+      #    a(1)    # => "foo"
+      #    b(y: 2) # => ['1','2','3',...]
+      #    c id: 3 # => Hash
       #  end
       #
       # +.single(:row)+ and +.single(:value)+ will return the first
       # row or the first value of the first row respectively, or +nil+
       # if no results are found. To generate a
       # {DbMod::Exceptions::NoResults} failure
       # instead of returning +nil+, use +.single(:row!)+ or
       # +.single(:value!)+.
       module Single
-        # For process_method_results
-        Configuration = DbMod::Statements::Configuration
-
-        # List of allowed parameters for {#single},
+        # List of allowed parameters for {MethodConfiguration#single},
         # and the methods used to process them.
         COERCERS = {
           value: Single::Value,
           value!: Single::RequiredValue,
           row: Single::Row,
           row!: Single::RequiredRow,
           column: Single::Column
         }
 
-        # Extend a method so that only some singular part of
-        # the SQL result set is returned.
-        # See above for more details.
+        # Extend the given method definition with additional
+        # result coercion.
         #
-        # @param mod [Module] module where the method has been defined
-        # @param name [Symbol] method name
-        # @param type [Symbol] one of {SINGLE_TYPES}
-        def self.extend_method(mod, name, type)
-          unless COERCERS.key? type
-            fail ArgumentError, "#{type} not in #{COERCERS.keys.join ', '}"
-          end
+        # @param definition [Proc] base method definition
+        # @param config [MethodConfiguration] method configuration
+        def self.extend(definition, config)
+          type = config[:single]
+          return definition if type.nil?
 
-          Configuration.process_method_results(mod, name, COERCERS[type])
+          Configuration.attach_result_processor definition, COERCERS[type]
         end
       end
     end
   end
 end