lib/bindata/multi_value.rb in bindata-0.9.2 vs lib/bindata/multi_value.rb in bindata-0.9.3

@@ -1,5 +1,6 @@
+require 'bindata/params'
 require 'bindata/struct'
 
 module BinData
   # A MultiValue is a declarative wrapper around Struct.
   #
@@ -42,15 +43,22 @@
   #                      endian of any numerics in this struct, or in any
   #                      nested data objects.
   class MultiValue < BinData::Struct
 
     class << self
+      extend Parameters
+
       # Register the names of all subclasses of this class.
       def inherited(subclass) #:nodoc:
         register(subclass.name, subclass)
       end
 
+      # Can this data object self reference itself?
+      def recursive?
+        true
+      end
+
       # Returns or sets the endianess of numerics used in this stucture.
       # Endianess is applied to the fields of this structure.
       # Valid values are :little and :big.
       def endian(endian = nil)
         @endian ||= nil
@@ -115,23 +123,49 @@
         # remember this field.  These fields will be recalled upon creating
         # an instance of this class
         @fields.push([type, name, params])
       end
 
-      # Returns a sanitized +params+ that is of the form expected
-      # by #initialize.
-      def sanitize_parameters(sanitizer, params)
-        params = params.dup
-
+      # Ensures that +params+ is of the form expected by #initialize.
+      def sanitize_parameters!(sanitizer, params)
         endian = params[:endian] || self.endian
         fields = params[:fields] || self.fields
         hide   = params[:hide]   || self.hide
 
         params[:endian] = endian unless endian.nil?
         params[:fields] = fields
         params[:hide]   = hide
 
+        # add default parameters
+        default_parameters.each do |k,v|
+          params[k] = v unless params.has_key?(k)
+        end
+
+        # ensure mandatory parameters exist
+        mandatory_parameters.each do |prm|
+          if not params.has_key?(prm)
+            raise ArgumentError, "parameter ':#{prm}' must be specified " +
+                                 "in #{self}"
+          end
+        end
+
         super(sanitizer, params)
+      end
+
+      # Sets the mandatory parameters used by this class.
+      def mandatory_parameters(*args) ; end
+
+      define_x_parameters(:mandatory, []) do |array, args|
+        args.each { |arg| array << arg.to_sym }
+        array.uniq!
+      end
+
+      # Sets the default parameters used by this class.
+      def default_parameters(params = {}); end
+
+      define_x_parameters(:default, {}) do |hash, args|
+        params = args.length > 0 ? args[0] : {}
+        hash.merge!(params)
       end
     end
   end
 end