How to replace "unsupported tokens in pdf strings" from the argument of a macro?

I’m trying to write a class where the arguments of the title{} and author{} commands, used for the title page, automatically call hypersetup{} to set the title and the author in the PDF metadata.

So far I use this piece of code (the apptocmd command is from etoolbox)

apptocmd{title}{
  hypersetup{
    pdftitle={#1}
  }
}{}{}

It works well, but often it happens that the user wants to insert a newline in the title to tune its appearance:

title{My very long long  title}

While everything still works, I get a warning about the newline being an unsupported token for pdf strings. The user is then forced to do:

title{My very long long texorpdfstring{}{} title}

to have the warning silenced.

So the question is: can I automatically remove (or better, replace) tokens that are not allowed in PDF strings according to hyperref, and to pass the filtered string to hypersetup to avoid the warning?

If a generic solution is not possible or too difficult, I’d want at the very least to just remove newlines or to replace them with spaces (I’ve tried to simply redefine the command in a group before calling hypersetup but I still get the warning).

documentclass{article}
usepackage{etoolbox}
usepackage{hyperref,xpatch}

xapptocmd{title}{%
  hypersetup{ pdftitle={#1} }%
}{}{}

pdfstringdefDisableCommands{%
  def{}%
}

title{My very long long  title}
author{Me}
date{today}

begin{document}

maketitle

end{document}