Re^4: JSON::XS and escaping literal strings

[Anonymous Monk]

Yes, it does.

I did some more research on this. I confirmed that the JSON spec does not require escaping of forward slashes.

Some platforms escape the forward slash by default but allow you to disable that behavior (e.g., php, json-c). I assume that's for safety.

Others expect you to escape it yourself when using it within the context of HTML. Ruby's ERB provides an escape_json method. Here's the essence of that:

JSON_ESCAPE = { "&" => '\u0026', ">" => '\u003e', "<" => '\u003c', "\u
+2028" => '\u2028', "\u2029" => '\u2029' }
JSON_ESCAPE_REGEXP = /[\u2028\u2029&><]/u

I've decided to move to Cpanel::JSON::XS, since it has support for more of the ::PP settings. And I've written a wrapper around it for our app that sets the appropriate defaults (e.g., escape_slash). I wrote a Perl version of the escape_json() from ERB.

{
  my %escape = (
    "&"        => '\u0026',
    ">"        => '\u003E',
    "<"        => '\u003C',
    '\x{2028}' => '\u2028',
    '\x{2029}' => '\u2029',
  );

  my $chars = join '', keys %escape;
  my $regex = qr/[$chars]/;

  sub escape_for_html {
    my $class = shift;

    @_ or croak 'no json supplied';
    my @json  = @_;

    foreach (@json) {
      s/($regex)/$escape{ $1 }/ge if defined;
    }

    return wantarray ? @json : join('', @json);
  }
}