use HTML::Entities qw( encode_entities );

sub text_to_ht_attr_val {
   my $s = @_ ? $_[0] : $_;
   $s = encode_entities($s);
   return qq{"$s"};
}

sub text_to_js_lit {
   my $s = @_ ? $_[0] : $_;
   $s =~ s/\\/\\\\/g;
   $s =~ s/'/\\'/g;
   # ...
   return qq{'$s'};
}

my $ht_to_insert = q{<tr id="someid"><td>}
                 . q{<a href="" onclick="this.function.test('')"></a>}
                 . q{</td></tr>};

my $js_onclick   = 'this.element.insert('
                 . text_to_js_lit($ht_to_insert)
                 . ')';

my $ht_dyn_ele   = '<a href="" onclick='
                 . text_to_ht_attr_val($js_onclick)
                 . '>';

print( "$ht_dyn_ele\n" );