lib/rgen/instantiator/json_instantiator.rb in rgen-0.5.3 vs lib/rgen/instantiator/json_instantiator.rb in rgen-0.5.4

@@ -3,34 +3,63 @@
 
 module RGen
 
 module Instantiator
 
+# JsonInstantiator is used to create RGen models from JSON.
+#
+# Each JSON object needs to have an attribute "_class" which is used to find
+# the metamodel class to instantiate. The value of "_class" should be the 
+# the relative qualified class name within the root package as a string. 
+#
+# If the option "short_class_names" is set to true, unqualified class names can be used.
+# In this case, metamodel classes are searched in the metamodel root package first.
+# If this search is not successful, all subpackages will be searched for the class name.
+#
 class JsonInstantiator
 
+  # Model elements will be created in evironment +env+,
+  # classes are looked for in metamodel package module +mm+,
+  # +options+ include:
+  #   short_class_names: if true subpackages will be searched for unqualifed class names (default: true)
+  # The options are also passed to the underlying QualifiedNameResolver.
+  #
   def initialize(env, mm, options={})
     @env = env
     @mm = mm
     @options = options
+    @short_class_names = !@options.has_key?(:short_class_names) || @options[:short_class_names]
     @unresolvedReferences = []
+    @classes = {}
+    @classes_flat = {}
+    mm.ecore.eAllClasses.each do |c|
+      @classes[c.instanceClass.name.sub(mm.name+"::","")] = c
+      @classes_flat[c.name] = c
+    end
     @parser = JsonParser.new(self)
   end
 
-  # creates the elements described by the json string +str+
-  # returns an array of ReferenceResolver::UnresolvedReference
+  # Creates the elements described by the json string +str+.
+  # Returns an array of ReferenceResolver::UnresolvedReference
   # describing the references which could not be resolved
+  #
   def instantiate(str)
     root = @parser.parse(str)
     resolver = QualifiedNameResolver.new(root, @options)
     resolver.resolveReferences(@unresolvedReferences)
   end
 
   def createObject(hash)
     className = hash["_class"]
     raise "no class information" unless className
-    clazz = @mm.const_get(className)
-    raise "class not found: #{className}" unless clazz
+    if @classes[className]
+      clazz = @classes[className].instanceClass
+    elsif @short_class_names && @classes_flat[className]
+      clazz = @classes_flat[className].instanceClass
+    else 
+      raise "class not found: #{className}"
+    end
     hash.delete("_class")
     urefs = []
     hash.keys.each do |k|
       f = eFeature(k, clazz)
       hash[k] = [hash[k]] if f.many && !hash[k].is_a?(Array)
@@ -66,10 +95,14 @@
   private
   
   def eFeature(name, clazz) 
     @eFeature ||= {}
     @eFeature[clazz] ||= {}
-    @eFeature[clazz][name] ||= clazz.ecore.eAllStructuralFeatures.find{|f| f.name == name}
+    unless @eFeature[clazz][name] 
+      feature = clazz.ecore.eAllStructuralFeatures.find{|f| f.name == name}
+      raise "feature '#{name}' not found in class '#{clazz}'" unless feature
+    end
+    @eFeature[clazz][name] ||= feature
   end
   
 end
 
 end