| Class::Workflow::Context - The context in which a transition is being applied. |
Class::Workflow::Context - The context in which a transition is being applied (optional).
use Class::Workflow::Context; # or a subclass or something
my $c = Class::Workflow::Context->new( ... );
my $new_instance = $transition->apply( $instance, $c );
If you need to pass arbitrary arguments to the workflow, a context object will usually help.
This specific context object provides stash, a writable hash which is
essentially free-for-all.
the Class::Workflow::Context manpage doesn't provide much and should generally be subclassed. It is designed to resemble the Catalyst context object.
Usage of a context object is completely optional, and the Class::Workflow manpage's other core objects (the Class::Workflow::State manpage, the Class::Workflow::Transition manpage, and the Class::Workflow::Instance manpage really don't care about context objects at all).
When writing a workflow that governs a web application, for example, transitions will generally expect explicit parameters, having to do with their specific responsibility, and more ``global'' parameters, like on behalf of which user is this transition being applied.
A context object is a way to provide a standard set of facilities that every transition can expect.
sub apply {
my ( $self, $instance, $c, %args ) = @_;
my $arg = $args{arg_i_care_about};
my $user = $c->user;
...
}
Conceptually $c is akin to the environment the workflow is being used in,
wheras %args are the actual parameters.
Note that this is only one of many possible conventions you can use in your workflow system.
The context should probably not be mutated by the workflow itself. That's what the workflow instance is for.
| Class::Workflow::Context - The context in which a transition is being applied. |