no fallar si el campo no tiene valor

app/views/posts/template_field/_table.haml

@@ -23,7 +23,7 @@
             - if @post.new?
               - value = nf.values
             - else
-              - value = @post.get_front_matter(template)[nf]
+              - value = @post.get_front_matter(template.key).try(:[], nf.key)
             = render 'posts/template_field/nested',
               template: nf,
               value: value,