/ 
Workflow-1.62
River stage zero No dependents
/ Workflow::Condition::Evaluate

NAME

Workflow::Condition::Evaluate - Inline condition that evaluates perl code for truth

VERSION

This documentation describes version 1.62 of this package

SYNOPSIS

<state name="foo">
    <action name="foo action">
        <condition test="$context->{foo} =~ /^Pita chips$/" />

DESCRIPTION

If you've got a simple test you can use Perl code inline instead of specifying a condition class. We differentiate by the 'test' attribute -- if it's present we assume it's Perl code to be evaluated.

While it's easy to abuse something like this with:

<condition>
  <test><![CDATA[
    if ( $context->{foo} =~ /^Pita (chips|snacks|bread)$/" ) {
         return $context->{bar} eq 'hummus';
    }
    else { ... }
    ]]>
  </test>
</condition>

It should provide a good balance.

OBJECT METHODS

new( \%params )

One of the \%params should be 'test', which contains the text to evaluate for truth.

evaluate( $wf )

Evaluate the text passed into the constructor: if the evaluation returns a true value then the condition passes; if it throws an exception or returns a false value, the condition fails.

We use Safe to provide a restricted compartment in which we evaluate the text. This should prevent any sneaky bastards from doing something like:

<state...>
    <action...>
        <condition test="system( 'rm -rf /' )" />

The text has access to one variable, for the moment:

$context

A hashref of all the parameters in the Workflow::Context object

SEE ALSO

  • Safe - From some quick research this module seems to have been packaged with core Perl 5.004+, and that's sufficiently ancient for me to not worry about people having it. If this is a problem for you shoot me an email.

COPYRIGHT

Copyright (c) 2004-2023 Chris Winters. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Please see the LICENSE

AUTHORS

Please see Workflow