title: Format textfield for CPF and CNPJ
body: <p>How should I handle text formatting in iOS? I'm not talking about Currency or Decimal styles. Since iOS doesn't have <code>setFormat()</code>, it's kind of complicated.</p>
  
  <p>Two examples of the format I want: <code>123.456.789-10</code> and <code>123.456.789/1000-00</code>.</p>
  
  <p>My aim is to format a text field as the user types. Like any normal site does when, for example, you type a phone number. It doesn't comes from a model or anything. The user just needs to type the numbers and when necessary I'll insert the <code>".","/"</code> or <code>"-"</code>.</p>