Fixing instance variable problem

Gemfile

@@ -3,6 +3,6 @@ source "http://rubygems.org"
 # Specify your gem's dependencies in my_project.gemspec
 gemspec
 
-gem "spork", "~> 0.9.0.rc9"
+gem "spork", ">= 0.9.0"
 gem "rspec-rails"
 gem "mocha"

lib/prawnto/model_renderer.rb

@@ -19,7 +19,7 @@ def self.to_string(template, calling_object = nil)
         instance.prawnto :inline => true, :instance_variables_from => calling_object
       end
 
-      return instance.render_to_string(:action => template, :template => false, :format => :pdf).html_safe
+      return instance.render_to_string(:action => template, :template => false, :formats => [:pdf]).html_safe
     end
 
   end

lib/prawnto/template_handlers/renderer.rb

@@ -33,16 +33,24 @@ def copy_instance_variables_from(object, exclude = [])
         vars = object.instance_variables.map(&:to_s) - exclude.map(&:to_s)
         vars.each { |name| instance_variable_set(name, object.instance_variable_get(name)) }
       end
+
+      def push_instance_variables_to(object, exclude = [])
+        vars = instance_variables.map(&:to_s) - exclude.map(&:to_s)
+        vars.each { |name| object.instance_variable_set(name, instance_variable_get(name)) }
+      end
 
+      # This method is a little hacky with pushing the instance variables back. I would prefer to use bindings, but wasn't having much luck.
       def method_missing(m, *args)
         begin
           super
         rescue
           if pdf.respond_to?(m.to_s)
             pdf.send(m, *args)
           elsif @calling_object.respond_to?(m.to_s)
+            push_instance_variables_to @calling_object
             @calling_object.send(m, *args)
           elsif @calling_object != @view_context and @view_context.respond_to?(m.to_s)
+            push_instance_variables_to @calling_object
             @view_context.send(m, *args)
           else
             raise

spec/dummy/app/controllers/test_controller.rb

@@ -9,5 +9,10 @@ def dsl_render
     @x = 1
     render :action => "dsl_render"
   end
+
+  def complex
+    @x = 1
+    render :action => "complex"
+  end
 
 end

spec/dummy/app/helpers/application_helper.rb

@@ -2,4 +2,8 @@ module ApplicationHelper
   def some_helper
     "this is from a helper"
   end
+
+  def x_output_helper
+    @x.to_s
+  end
 end

spec/dummy/app/models/super_model.rb

@@ -2,7 +2,7 @@ class SuperModel
 
   def to_pdf
     @x = 1
-    Prawnto::ModelRenderer.to_string "test/default_render.pdf", self
+    Prawnto::ModelRenderer.to_string "test/default_render", self
   end
 
 end

spec/dummy/app/views/test/complex.pdf.prawn

@@ -0,0 +1,8 @@
+text "Complex Example"
+text "@x = #{@x}"
+@x = 2
+text x_output_helper
+
+if @x.to_s != x_output_helper
+  raise "Variable did not carry over"
+end

spec/dummy/config/routes.rb

@@ -1,6 +1,7 @@
 Rails.application.routes.draw do
   get "/default_render" => "test#default_render"
   get "/dsl_render" => "test#dsl_render"
+  get "/complex" => "test#complex"
 
   root :to => "test#default_render"
 end

spec/integrations/test_controller_spec.rb

@@ -2,7 +2,7 @@
 
 describe TestController do
 
-  describe "GET default_render" do
+  describe "simple" do
     it "returns correct PDF" do
       get "/default_render.pdf"
       response.should be_success
@@ -14,7 +14,7 @@
   end
 
 
-  describe "GET dsl_render" do
+  describe "dsl" do
     it "returns correct PDF" do
       get "/dsl_render.pdf"
       response.should be_success
@@ -25,4 +25,8 @@
     end
   end
 
+  it "uses changed instance values in helpers" do
+    expect { get "/complex.pdf" }.should_not raise_error
+  end
+
 end