[Catalyst] [again] die() in an action chain : does not break the chain !

[Ashley]

I've been threatening for more than a year to write a plugin to do this.
I wrote to ask for CPAN/method name suggestions, Aristotle gave me  
good advice
which I'll have to dig up.

If you want to do it yourself you would just put a new method which dies
and detaches. Then in your examples below you'd call
$c->error_out() (I think this is my original stupid name which Aristotle
tried to save us all from) and it would throw your exception (or perhaps
something out of $c->errors) and $c->detach("end")... maybe. It's been
a year since I looked at it though I think it's a good idea.

-Ashley

On Mar 14, 2008, at 12:54 AM, Dami Laurent (PJ) wrote:

> Hello list,
>
> Sorry, I already asked the same question a couple of days ago, but
> probably I was not clear enough.
>
> My problem is that if there is an exception at the entry point of an
> action chain, processing nevertheless continues until the endpoint of
> the chain.
>
> Consider for example the following action chain :
>
>    sub one : Chained("/") :PathPart("one") :CaptureArgs(0) {
>      my ($self, $c) = @_;
>      $c->{stash}{msg} = "start_work";
>      die "die in one";
>    }
>
>    sub two : Chained("one") :PathPart("two") :CaptureArgs(0) {
>      my ($self, $c) = @_;
>      $c->{stash}{msg} .= ", ". $self->expensive_work($c);
>      die "die in two";
>    }
>
>    sub three : Chained("two") :PathPart("three") :Args(0) {
>      my ($self, $c) = @_;
>      $c->{stash}{msg} .= ", ". $self->expensive_work($c) . " again";
>      die "die in three";
>      $c->response->body($c->stash->{msg});
>    }
>
>    sub expensive_work {
>      my ($self, $c) = @_;
>      return "this took me a long time";
>    }
>
> and the following finalize_error function :
>
> sub finalize_error {
>   my ($c) = @_;
>   my $body = "got errors : " . join ("\n", @{$c->error})
>            . "\nand message was :\n" . $c->stash->{msg};
>   $c->response->body($body);
> }
>
> This yields
>
>   got errors : Caught exception in
> Cata_exceptions::Controller::Root->one "die in one at
> D:/Temp/Cata_exceptions/scripts/../lib/Cata_exceptions/Controller/ 
> Root.p
> m line 22."
>   Caught exception in Cata_exceptions::Controller::Root->two "die  
> in two
> at
> D:/Temp/Cata_exceptions/scripts/../lib/Cata_exceptions/Controller/ 
> Root.p
> m line 28."
>   Caught exception in Cata_exceptions::Controller::Root->three "die in
> three at
> D:/Temp/Cata_exceptions/scripts/../lib/Cata_exceptions/Controller/ 
> Root.p
> m line 35."
>   and message was :
>   start_work, this took me a long time, this took me a long time again
>
>
> Now the question is : how to avoid calling expensive_work() ? Is  
> there a
> way to tune up the chaining mechanism so that it would automatically
> detach() at the first exception ?
>
> Thanks in advance, Laurent Dami
>
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