[Dancer-users] Follow-up: extending the serializer

[Mr. Puneet Kishor]

On Jun 7, 2011, at 4:51 PM, Mr. Puneet Kishor wrote:

> I am trying to write a new serializer plugin called `Dancer::Serializer::Tgz` modeled after Data::Dumper, JSON, etc. The idea is that, in conjunction with `Dancer::Plugin::REST` and `Dancer::Serializer::Mutable`, the user would be able to request data in .tgz format on demand like so --
> 
> $ curl http://example.com/employees.tgz
> 
> Here is my baby code, and it gives me a rather unhelpful "an internal error occurred". What am I doing wrong?

After much fiddling, I was able to see the following errors --

in my Apache error log, I get

Deep recursion on subroutine "Dancer::Error::render" at ../Dancer.pm line 312.
Deep recursion on subroutine "Dancer::Error::_render_serialized" at ../Dancer/Error.pm line 167.
Deep recursion on subroutine "Dancer::Serializer::Tgz::serialize" at ../Dancer/Error.pm line 177.
Deep recursion on subroutine "Dancer::_send_file" ../Dancer.pm line 140.


If I uncomment the `sub content_type {'application/gzip'}` I also get 

Subroutine content_type redefined at ../Dancer/Serializer/Tgz.pm line 43.

Also, if I comment the `send_file` command in serialize(), I actually do get a result.tgz. If I untar that result.tgz, I see the following text

{
   "error" : "Serializer (Dancer::Serializer::Tgz) failed at serializing Dancer::Error=HASH(0x100a93008):\nencountered object 'Dancer::Error=HASH(0x100a93008)', but neither allow_blessed nor convert_blessed settings are enabled at (eval 71) line 153.\n"
}

What am I doing wrong?

> Note: in this case, only the serializer (downloading data) makes sense; the deserializer doesn't make any sense.
> 
> -----
> 
> package Dancer::Serializer::Tgz;
> 
> use strict;
> use warnings;
> use Carp;
> use Dancer ':syntax';
> use Archive::Tar;
> use base 'Dancer::Serializer::Abstract';
> 
> # helpers
> 
> sub from_tgz {
>    my ($string) = @_;
>    my $s = Dancer::Serializer::Tgz->new;
>    $s->deserialize($string);
> }
> 
> sub to_tgz {
>    my ($data) = @_;
>    my $s = Dancer::Serializer::Tgz->new;
>    $s->serialize($data);
> }
> 
> sub serialize {
>    my ($self, $entity) = @_;
> 
>    my $tar = Archive::Tar->new;
>    $tar->add_data('result', to_json($entity));
> 
>    my $file = '/tmp/result.tgz';
>    $tar->write($file, COMPRESS_GZIP);
>    send_file($file, content_type => 'application/gzip', system_path => 1);
> }
> 
> sub deserialize {
>    my ($self, $content) = @_;
>    croak "not yet implemented";
> }
> 
> sub content_type {'application/gzip'}
> 
> 1;