Transform::Alert::Input - Base role for Transform::Alert input types


This is the role used for all input types.



The InputGrp object that constructed it.


Hash ref of the connection options (from configuration).


All I/O types require the following methods below. Unless specified, all of the methods should report a true value on success or undef on error. The methods are responsible for their own error logging.


Called on every new interval, if opened returns false. Most types would open up the connection here and run through any "pre-get/send" setup. Though, in the case of UDP, this isn't always necessary.


Must return a true value if the connection is currently open and valid, or false otherwise.


Called on each message/alert that is to be parsed through the templates and sent to the outputs. This is called on a loop, so the I/O cycle will happen on a per-alert basis.

This must return a list of:

    (\$text, $hash)

or undef on error. The $text is used for Template validation, while the $hash is stored in the Output/Munger variables as p. See "OUTPUTS" in Transform::Alert::Input::POP3 for an example.


Must return a true value if there are no more alerts available to process, or false otherwise.


Called after the interval loop has been completed. This should close the connection and run through any cleanup.

This method should double-check all I/O cleanup with the opened method to ensure that close doesn't fail. This is important if the loop detects that the opened method is false, since it will try a close before trying to re-open.


Persistent connections can be done by defining close in such a way that it still keeps the connection online, and making sure opened can handle the state. Take special care to check that the connection is indeed valid and the module can handle re-opens properly.


The project homepage is

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit to find a CPAN site near you, or see


Brendan Byrd <>


This software is Copyright (c) 2013 by Brendan Byrd.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)