lib/ncs_navigator/mdes/specification.rb in ncs_mdes-0.2.0 vs lib/ncs_navigator/mdes/specification.rb in ncs_mdes-0.3.0

@@ -1,10 +1,11 @@
 require 'ncs_navigator/mdes'
 
 require 'forwardable'
 require 'logger'
 require 'nokogiri'
+require 'yaml'
 
 module NcsNavigator::Mdes
   class Specification
     extend Forwardable
 
@@ -41,10 +42,31 @@
     def xsd
       @xsd ||= Nokogiri::XML(File.read source_documents.schema)
     end
 
     ##
+    # @return [Hash] the loaded heuristic overrides, or a default
+    #   (empty) set
+    def heuristic_overrides
+      @heuristic_overrides ||=
+        begin
+          if File.exist?(source_documents.heuristic_overrides)
+            empty_overrides.merge(YAML.load(File.read source_documents.heuristic_overrides))
+          else
+            empty_overrides
+          end
+        end
+    end
+
+    def empty_overrides
+      {
+        'foreign_keys' => { }
+      }
+    end
+    private :empty_overrides
+
+    ##
     # @return [Array<TransmissionTable>] all the transmission tables
     #   in this version of the MDES.
     def transmission_tables
       @transmission_tables ||= read_transmission_tables
     end
@@ -55,12 +77,44 @@
         source_documents.xmlns
       ).collect { |table_elt|
         TransmissionTable.from_element(table_elt, :log => @log)
       }.tap { |tables|
         tables.each { |t| t.variables.each { |v| v.resolve_type!(types, :log => @log) } }
+        # All types must be resolved before doing FK resolution or
+        # forward refs are missed.
+        tables.each { |t|
+          fk_overrides = heuristic_overrides['foreign_keys'][t.name] || { }
+          t.variables.each { |v|
+            v.resolve_foreign_key!(tables, fk_overrides[v.name], :log => @log)
+          }
+        }
       }
     end
     private :read_transmission_tables
+
+    ##
+    # A shortcut for accessing particular {#transmission_tables}.
+    #
+    # @overload [](table_name)
+    #   Retrieves a single table by name.
+    #   @param [String] table_name the transmission table to return.
+    #   @return [TransmissionTable,nil] the matching table or nothing.
+    #
+    # @overload [](pattern)
+    #   Searches the transmission tables by name.
+    #   @param [Regexp] pattern the pattern to match the name against.
+    #   @return [Array<TransmissionTable>] the matching tables (or an
+    #     empty array).
+    def [](criterion)
+      case criterion
+      when Regexp
+        transmission_tables.select { |t| t.name =~ criterion }
+      when String
+        transmission_tables.detect { |t| t.name == criterion }
+      else
+        fail "Unexpected criterion #{criterion.inspect}"
+      end
+    end
 
     ##
     # @return [Array<VariableType>] all the named types in the
     #   MDES. This includes all the code lists.
     def types