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

NAME

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

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 the Safe manpage 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 the Workflow::Context manpage object

SEE ALSO

the Safe manpage - 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 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.

AUTHORS

Chris Winters <chris@cwinters.com>

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