excluding activerecord properties xml digest rails

i have an activerecord denote i modify xml, nonetheless i wish properties rendered xml. there parameter i pass news slight keep ability being rendered xml?

below an instance i am articulate about.

def show
  @person = person.find(params[:id])
  respond_to |format|
    format.xml { news :xml => @person }
  end
end

produces following xml

<person>
  <name>paul</name>
  <age>25</age>
  <phone>555.555.5555</phone>
</person>

however, i wish phone ability shown. there parameter news slight excludes properties being rendered xml? kind following example

def show
  @person = person.find(params[:id])
  respond_to |format|
    format.xml { news :xml => @person, :exclude_attribute => :phone }
  end
end

which news following xml

<person>
  <name>paul</name>
  <age>25</age>
</person>