Hi there! Sorry for not replying to this earlier, I've been terribly busy :/
I haven't released an API to explicitly call the original filters yet,
mainly because I didn't thing people would want that. But don't fear,
just keep on reading!
In your particular case, the simplest solution without breaking
encapsulation is to create a variable/structure with the items you want
from the original object, then dumping it using p(). For example:
use DDP filters => {
'HTTP::Response' => sub {
my ($res, $p) = @_;
my $decoded = $res->decoded_content;
return p( \$decoded, $p );
}
};
Of course, it may be the case where you want to see details of the
entire (cloned) object. Well, when you create a filter in Data::Printer,
you're not replacing the original one, you're just stacking yours on top
of it. As it is written under the 'Filters' section of the documentation:
"Your filters are supposed to return a defined value (usually, the
string you want to print). If you don't, Data::Printer will let the next
filter of that same type have a go, or just fallback to the defaults."
So, here's how you would change your data and still be able to forward
it to the original handler:
use DDP filters => {
'HTTP::Response' => sub {
my ($res, $p) = @_;
# been here before? Forward to the original handler!
return if exists $res->{decoded_content};
# first timer? Come on in!
my $clone = $res->clone;
$clone->{decoded_content} = $clone->decoded_content;
return p($clone, $p);
}
};
This should avoid the recursion issue!
I have added this tip under 'creating fiddling filters' on Data::Printer
0.34, credited under 'dirk'. If you let me have your full name and/or
cpan|irc handle, I'll gladly update it :)
Thanks!
On Mon Oct 01 05:52:48 2012, dirk wrote:
Show quoted text> On Sun Sep 30 19:36:28 2012, dirk wrote:
> > Can you add an example of adding a calculated field to the orignal ref?
> > An example would be if you had an HTTP::Response, but wanted to add the
> > decoded_content to the ref if the _content field was encoded (e.g.
> > compressed).
> >
> > I tried this, but of course it had recursion problems:
> >
> > 'HTTP::Response' => sub {
> > $_[0]->{decoded_content} = $_[0]->decoded_content;
> > return p($_[0]);
> > },
>
> I figured out how to do it, but I'm not sure how wise it is to directly
> use the the internal _class function. Is there an alternative to this?
>
> filters => {
> 'HTTP::Response' => sub {
> my $res = shift;
> return unless $res->content_encoding;
> # Don't modify the original object.
> $res = $res->clone;
> $res->{decoded_content} = $res->decoded_content;
> return _class($res, @_);
> }
> }
