lib/axlsx/drawing/graphic_frame.rb in axlsx-2.0.1 vs lib/axlsx/drawing/graphic_frame.rb in axlsx-2.1.0.pre

@@ -33,19 +33,19 @@
     # @return [String]
     def to_xml_string(str = '')
       # macro attribute should be optional!
       str << '<xdr:graphicFrame>'
       str << '<xdr:nvGraphicFramePr>'
-      str << '<xdr:cNvPr id="' << @anchor.drawing.index.to_s << '" name="' << 'item_' << @anchor.drawing.index.to_s << '"/>'
+      str << ('<xdr:cNvPr id="' << @anchor.drawing.index.to_s << '" name="' << 'item_' << @anchor.drawing.index.to_s << '"/>')
       str << '<xdr:cNvGraphicFramePr/>'
       str << '</xdr:nvGraphicFramePr>'
       str << '<xdr:xfrm>'
       str << '<a:off x="0" y="0"/>'
       str << '<a:ext cx="0" cy="0"/>'
       str << '</xdr:xfrm>'
       str << '<a:graphic>'
-      str << '<a:graphicData uri="' << XML_NS_C << '">'
-      str << '<c:chart xmlns:c="' << XML_NS_C << '" xmlns:r="' << XML_NS_R << '" r:id="' << rId << '"/>'
+      str << ('<a:graphicData uri="' << XML_NS_C << '">')
+      str << ('<c:chart xmlns:c="' << XML_NS_C << '" xmlns:r="' << XML_NS_R << '" r:id="' << rId << '"/>')
       str << '</a:graphicData>'
       str << '</a:graphic>'
       str << '</xdr:graphicFrame>'
     end