class Roda::RodaPlugins::ErubisEscaping::Eruby

postfix conditionals inside <%= %> tags.
Subclass that works with specified escaper, also handling

def add_expr_escaped(src, code)

Use escaping object to escape the code, and handle postfix conditionals. 
def add_expr_escaped(src, code)
  src << " " << @bufvar << " << _erubis_escaper.escape_xml((" <<  code << "));"
end

def convert_input(codebuf, input)

Set escaping object to a local variable 
def convert_input(codebuf, input)
  codebuf << '_erubis_escaper = render_opts[:escaper];'
  super
end