new template rendering option: :scope - eval in a scope other than self

Signed-off-by: Konstantin Haase <konstantin.mailinglists@googlemail.com>

lib/sinatra/base.rb

@@ -483,17 +483,18 @@ def render(engine, data, options={}, locals={}, &block)
       layout          = @default_layout if layout.nil? or layout == true
       content_type    = options.delete(:content_type)  || options.delete(:default_content_type)
       layout_engine   = options.delete(:layout_engine) || engine
+      scope           = options.delete(:scope)         || self
 
       # compile and render template
       layout_was      = @default_layout
       @default_layout = false
       template        = compile_template(engine, data, options, views)
-      output          = template.render(self, locals, &block)
+      output          = template.render(scope, locals, &block)
       @default_layout = layout_was
 
       # render layout
       if layout
-        options = options.merge(:views => views, :layout => false, :eat_errors => eat_errors)
+        options = options.merge(:views => views, :layout => false, :eat_errors => eat_errors, :scope => scope)
         catch(:layout_missing) { output = render(layout_engine, layout, options, locals) { output }}
       end
 

test/templates_test.rb

@@ -229,6 +229,23 @@ def with_default_layout
     render_app { render :erb, :calc }
     assert_equal '2', body
   end
+
+  it "passes scope to the template" do
+    mock_app {
+      template :scoped do
+        'Hello <%= foo %>'
+      end
+
+      get '/' do
+        some_scope = Class.new; def foo; 'World!'; end;
+        erb :scoped, :scope => some_scope
+      end
+    }
+
+    get '/'
+    assert ok?
+    assert_equal 'Hello World!', body
+  end
 end
 
 # __END__ : this is not the real end of the script.