lib/praxis-blueprints/renderer.rb in praxis-blueprints-3.0 vs lib/praxis-blueprints/renderer.rb in praxis-blueprints-3.1

@@ -1,10 +1,25 @@
 module Praxis
   class Renderer
     attr_reader :include_nil
     attr_reader :cache
 
+    class CircularRenderingError < StandardError
+      attr_reader :object
+      attr_reader :context
+
+      def initialize(object,context)
+        @object = object
+        @context = context
+
+        first = Attributor.humanize_context(context[0..10])
+        last = Attributor.humanize_context(context[-5..-1])
+        pretty_context = "#{first}...#{last}"
+        super("SystemStackError in rendering #{object.class} with context: #{pretty_context}")
+      end
+    end
+
     def initialize(include_nil: false)
       @cache = Hash.new do |hash,key|
         hash[key] = Hash.new
       end
 
@@ -33,9 +48,11 @@
       elsif object.kind_of? Praxis::Blueprint
         @cache[object.object_id][fields.object_id] ||= _render(object,fields, view, context: context)
       else
         _render(object,fields, view, context: context)
       end
+    rescue SystemStackError
+      raise CircularRenderingError.new(object, context)
     end
 
     def _render(object, fields, view=nil, context: Attributor::DEFAULT_ROOT_CONTEXT)
       return object if fields == true