lib/rails_erd/diagram/graphviz.rb in rails-erd-1.5.2 vs lib/rails_erd/diagram/graphviz.rb in rails-erd-1.6.0

@@ -84,10 +84,15 @@
         penwidth:      1.0,
         labelangle:    32,
         labeldistance: 1.8,
       }
 
+      # Default cluster attributes.
+      CLUSTER_ATTRIBUTES = {
+        margin: "10,10"
+      }
+
       module Simple
         def entity_style(entity, attributes)
           {}.tap do |options|
             options[:fontcolor] = options[:color] = :grey60 if entity.virtual?
           end
@@ -214,12 +219,14 @@
       end
 
       each_entity do |entity, attributes|
         if options[:cluster] && entity.namespace
           cluster_name = "cluster_#{entity.namespace}"
+          cluster_options = CLUSTER_ATTRIBUTES.merge(label: entity.namespace)
           cluster = graph.get_graph(cluster_name) ||
-                    graph.add_graph(cluster_name, label: entity.namespace)
+                    graph.add_graph(cluster_name, cluster_options)
+
           draw_cluster_node cluster, entity.name, entity_options(entity, attributes)
         else
           draw_node entity.name, entity_options(entity, attributes)
         end
       end
@@ -301,10 +308,15 @@
       def specialization_options(specialization)
         specialization_style(specialization)
       end
 
       def read_template(type)
-        ERB.new(File.read(File.expand_path("templates/#{NODE_LABEL_TEMPLATES[type]}", File.dirname(__FILE__))), nil, "<>")
+        template_text = File.read(File.expand_path("templates/#{NODE_LABEL_TEMPLATES[type]}", File.dirname(__FILE__)))
+        if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
+          ERB.new(template_text, trim_mode: "<>")
+        else
+          ERB.new(template_text, nil, "<>")
+        end
       end
     end
   end
 end