NAME¶
Message::Passing::Role::HasErrorChain - A role for components which can report
errors
SYNOPSIS¶
# Note this is an example package, and does not really exist!
package Message::Passing::Output::ErrorAllMessages;
use Moo;
use namespace::clean -except => 'meta';
with qw/
Message::Passing::Role::Output
Message::Passing::Role::HasErrorChain
/;
sub consume {
my ($self, $message) = @_;
$self->error->consume($message);
}
DESCRIPTION¶
Some components can create an error stream in addition to a message stream.
METHODS¶
error¶
An attribute containing the error chain.
By default, this is a chain of:
- Message::Passing::Filter::Encoder::JSON
- Message::Passing::Output::STDOUT
WARNINGS¶
ERROR CHAINS CAN LOOP¶
If you override the error chain output, be sure that the error chain does not go
into your normal log path! This is because if you suddenly have errors in your
normal log path, and you then start logging these errors, this causes more
errors - causing you to generate a message loop.
ENCODING IN ERROR CHAINS¶
If you emit something which cannot be encoded to an error chain then the
encoding error will likely be emitted by the error chain - this can again
cause loops and other issues.
All components which use error chains should be very careful to output data
which they are entirely certain will be able to be encoded.
This module exists due to the wonderful people at Suretec Systems Ltd.
<
http://www.suretecsystems.com/> who sponsored its development for its
VoIP division called SureVoIP <
http://www.surevoip.co.uk/> for use with
the SureVoIP API -
<
http://www.surevoip.co.uk/support/wiki/api_documentation>
AUTHOR, COPYRIGHT AND LICENSE¶
See Message::Passing.