Handeling UserAgent / DOM errors

[hussam-qasem]

1. How do I detect UserAgent errors? (I can't seem to catch them). For example:

my $ua = Mojo::UserAgent->new;
$ua->proxy->https('http://127.0.0.1:3128');
my $tx = $ua->get( "https://www.mojolicious.org/index.html" );
die $tx->result->message unless $tx->result->is_success;

produces Proxy connection failed. How can I capture this error?

2. What's the preferred way to handle DOM errors? For example:

eval {
    say STDOUT "name: ",
	Mojo::DOM->new
	->parse( '<tr><td>Username:</td><td><input type="text" Xname="g3x761111" /></td></tr>' )
	->at( 'input[type="text"][name^="g3"]' )->attr->{name};
};

if ($@) {
    warn "Error accessing input element: $@";
}

vs.

my $dom = Mojo::DOM->new
  ->parse( '<tr><td>Username:</td><td><input type="text" Xname="g3x761111" /></td></tr>' )
  ->at( 'input[type="text"][name^="g3"]' );
say STDOUT "name: ", $dom->attr->{name} if $dom;
warn "Error accessing input element" unless $dom;

[hussam-qasem]

1. How do I detect `UserAgent` errors? (I can't seem to catch them). For example:

my $ua = Mojo::UserAgent->new;
$ua->proxy->https('http://127.0.0.1:3128');
my $tx = $ua->get( "https://www.mojolicious.org/index.html" );
die $tx->result->message unless $tx->result->is_success;

produces Proxy connection failed. How can I capture this error?

So I figured one part. It seems accessing the result object throws the exception.

my $ua = Mojo::UserAgent->new;
$ua->proxy->https('http://127.0.0.1:3128');
my $tx = $ua->get( "https://www.mojolicious.org/index.html" );
my $result = eval { $tx->result };
die "Error occurred: $@" if $@;
die $result->code."/".$result->message unless $result->is_success;

[daleif]

Erh, did you have a look at https://docs.mojolicious.org/Mojo/UserAgent, wouldn't the other messages be able to catch or detect these?

[hussam-qasem]

Thanks for your response. Would you kindly elaborate with an example? I don't see anything relevant in the UserAgent documentation. However, Mojo::Exception provides some insight:

#!/usr/bin/env perl
use Mojo::UserAgent;
use Mojo::Exception qw(check);

my $ua = Mojo::UserAgent->new;
$ua->proxy->https('http://127.0.0.1:3128');
my $tx = $ua->get( "https://www.mojolicious.org/index.html" );;
eval { $tx->result };
check $@ => [
    default => sub { die "Error occurred: $_" },
    ];
die $tx->result->code."/".$tx->result->message unless $tx->result->is_success;

I'm using default because I don't know how to get the actual exception name.

[kraih]

The whole point ->result exists is to throw an exception. If you don't want that you could just call ->res instead and check manually for errors.

[hussam-qasem]

Thank you @kraih for the prompt response. I was not aware of the difference - I now see it in Mojo::Transaction