Basic graph

A basic example of graph/workflow managed by Finite

Overview

In this example, we'll see a basic Document workflow, following this graph :

                              Reject
                       |-----------------|
  Transitions          |                 |
                       v    Propose      |       Accept
  States            Draft ----------> Proposed ----------> Accepted

  Properties     * Deletable                              * Printable
                 * Editable

Implement your document class

<?php

class Document implements Finite\StatefulInterface
{
    private $state;

    public function getFiniteState()
    {
        return $this->state;
    }

    public function setFiniteState($state)
    {
        $this->state = $state;
    }
}

Configure your graph

<?php

$loader = new Finite\Loader\ArrayLoader([
    'class'   => 'Document',
    'states'  => [
        'draft' => [
            'type'       => Finite\State\StateInterface::TYPE_INITIAL,
            'properties' => ['deletable' => true, 'editable' => true],
        ],
        'proposed' => [
            'type'       => Finite\State\StateInterface::TYPE_NORMAL,
            'properties' => [],
        ],
        'accepted' => [
            'type'       => Finite\State\StateInterface::TYPE_FINAL,
            'properties' => ['printable' => true],
        ]
    ],
    'transitions' => [
        'propose' => ['from' => ['draft'], 'to' => 'proposed'],
        'accept'  => ['from' => ['proposed'], 'to' => 'accepted'],
        'reject'  => ['from' => ['proposed'], 'to' => 'draft'],
    ],
]);

$document = new Document;
$stateMachine = new Finite\StateMachine\StateMachine($document);
$loader->load($stateMachine);
$stateMachine->initialize();

At this point, your Workflow / State graph is fully accessible to the state machine, and you can start to work with your workflow.

Working with workflow

Current state

<?php
// Get the name of the current state
$stateMachine->getCurrentState()->getName();
// string(5) "draft"

// List the currently accessible properties, and their values
$stateMachine->getCurrentState()->getProperties();
// array(2) {
//     'deletable' => bool(true)
//     'editable' => bool(true)
// }

// Checks if "deletable" property is defined
$stateMachine->getCurrentState()->has('deletable');
// bool(true)

// Checks if "printable" property is defined
$stateMachine->getCurrentState()->has('printable');
// bool(false)

Available transitions

<?php

// Retrieve available transitions
var_dump($stateMachine->getCurrentState()->getTransitions());
// array(1) {
//      [0] => string(7) "propose"
// }

// Check if we can apply the "propose" transition
var_dump($stateMachine->getCurrentState()->can('propose'));
// bool(true)

// Check if we can apply the "accept" transition
var_dump($stateMachine->getCurrentState()->can('accept'));
// bool(false)

Apply transition

<?php

// Trying to apply a not accessible transition
try {
    $stateMachine->apply('accept');
} catch (\Finite\Exception\StateException $e) {
    echo $e->getMessage();
}
// The "accept" transition can not be applied to the "draft" state.

// Applying a transition
$stateMachine->apply('propose');
$stateMachine->getCurrentState()->getName();
// string(7) "proposed"
$document->getFiniteState();
// string(7) "proposed"