On Thu, 8 Jun 2000, Richard L. Goerwitz wrote:
> > As far as I've seen, the fastest template systems are the ones that
> > convert the template to Perl code. So that's what I do. The templates all
> > call a method (in my case $Response->Write()) which appends to a
> > string. If there are no exceptions (see the guide) the string is sent to
> > the browser. If there are exceptions, I parse/send an error template with
> > the error in the template.
>
> I'm trying to follow this explanation, but can't quite visualize what
> you're doing. I wonder if you could perhaps post a code fragment to the
> list elucidating...
Err... It's a bit complicated. I'm porting someone else's template system
from a VB environment, and it's not pretty, but basically I have a
response class with a Write method that looks like this:
sub Write {
my $self = shift;
$self->{output} .= join('', @_);
}
I then have templates that get turned from this:
<html><title><xx-mytag></title></html>
Into the following Perl code:
sub handler {
my ($Response, <otherobjects>, $__params) = @_;
$Response->Write(q|<html><title>|);
$Response->Write($__params{'xx-mytag'});
$Response->Write(q|</title></html>|);
}
And then my handler looks like:
sub handler {
my $r = shift;
# setup $Response, etc...
...
eval {
do_stuff();
}
if ($@) {
if ($@->isa('Foo')) {
# process foo exception
}
elsif ($@->isa('Bar')) {
# process bar exception
}
elsif ($@->isa('Error')) {
# error
$db->rollback();
Template->Output('error.html', text => $@->{error});
}
}
$db->commit;
$Response->Send;
return OK;
and do_stuff() calls:
Template->Output('templatefilename', %params);
But if it errors out for some reason (db fails, etc) then it gets trapped
by the exception handler, and instead of giving a 500 internal server
error, we get an nice error page which they can take massive .bmp screen
shots of and mail to their sysadmin over a 56k connection ;-)
See the guide for the exception handling class I use (or variant of).
--
<Matt/>
Fastnet Software Ltd. High Performance Web Specialists
Providing mod_perl, XML, Sybase and Oracle solutions
Email for training and consultancy availability.
http://sergeant.org http://xml.sergeant.org
