[htmltmpl] Patch to encode iso-8859-1 using HTML::Entities

[Dave W. S. <dw...@da...>]

We ran headlong into the need to add iso-8859-1 (Latin1) support to a =
large
webapp that used over a hundred templates. Rather than tracking down the
many places where we stuffed parameters, then modify them to use
HTML::Entities (and remove "ESCAPE=3DHTML"), I took the "simplest thing =
that
could possibly work" path, and added an 'encode_entities' option to =
new().
When true, it causes 7-bit unclean characters to be escaped via
HTML::Entities::encode_entities() when "ESCAPE=3DHTML" is used.

With the patch, getting most of the way to Latin1 support was a simple =
as
adding

  my $template =3D HTML::Template->new(
    filename =3D> $template,
    global_vars =3D> 1,
    cache =3D> 1,
+   encode_entities =3D> 1,
  );


The performance hit (for the encode_entities =3D> 1 case) is < 1% for =
our app,
as measured via our unit test suite.=20

The patch for HTML::Template 2.7, including doc changes and unit tests, =
is
http://www.davewsmith.com/code/HTML-Template-2_7-encode.diff

To maintain backward compatibility for people who expect single-quotes =
to be
escaped (e.g., for existing unit tests), single quotes are escaped =
either
way.

Dave