Extracted common data class methods into mixin modules

Data/Scripts/011_Data/014_Data.rb

@@ -0,0 +1,75 @@
+class Data
+
+  # A mixin module for data classes which provides common class methods (called
+  # by Data::Thing.method) that provide access to data held within. Assumes the
+  # data class's data is stored in a class constant hash called DATA.
+  module ClassMethods
+    # @param other [Symbol, self, Integer]
+    # @return [Boolean] whether the given other is defined as a self
+    def exists?(other)
+      return false if other.nil?
+      validate other => [Symbol, self.class, Integer]
+      other = other.id if other.is_a?(self.class)
+      return !self::DATA[other].nil?
+    end
+
+    # @param other [Symbol, self, Integer]
+    # @return [self]
+    def get(other)
+      validate other => [Symbol, self.class, Integer]
+      return other if other.is_a?(self.class)
+#      if other.is_a?(Integer)
+#        p "Please switch to symbols, thanks."
+#      end
+      raise "Unknown ID #{other}." unless self::DATA.has_key?(other)
+      return self::DATA[other]
+    end
+
+    def try_get(other)
+      return nil if other.nil?
+      validate other => [Symbol, self.class, Integer]
+      return other if other.is_a?(self.class)
+#      if other.is_a?(Integer)
+#        p "Please switch to symbols, thanks."
+#      end
+      return (self::DATA.has_key?(other)) ? self::DATA[other] : nil
+    end
+
+    def each
+      keys = self::DATA.keys
+      keys.sort! { |a, b| a.to_s <=> b.to_s }
+      keys.each do |key|
+        yield self::DATA[key] if key.is_a?(Symbol)
+      end
+    end
+
+    def load
+      const_set(:DATA, load_data("Data/#{self::DATA_FILENAME}"))
+    end
+
+    def save
+      save_data(self::DATA, "Data/#{self::DATA_FILENAME}")
+    end
+  end
+
+  # A mixin module for data classes which provides common instance methods
+  # (called by thing.method) that analyse the data of a particular thing which
+  # the instance represents.
+  module InstanceMethods
+    # @param other [Symbol, self.class, Integer]
+    # @return [Boolean] whether other represents the same thing as this thing
+    def ==(other)
+      return false if other.nil?
+      validate other => [Symbol, self.class, Integer]
+      if other.is_a?(Symbol)
+        return @id == other
+      elsif other.is_a?(self.class)
+        return @id == other.id
+      elsif other.is_a?(Integer)
+        return @id_number == other
+      end
+      return false
+    end
+  end
+
+end