PHP code example of byjg / statemachine

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

byjg / statemachine example snippets

$stA = new State("A");
$stB = new State("B");
$stC = new State("C");
$stD = new State("D");

use ByJG\StateMachine\TransitionConditionInterface;

$transitionA_B = new Transition($stA, $stB);
$transitionA_C = new Transition($stA, $stC);

$condition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return !is_null($data);
    }
};
$transitionB_D = new Transition($stB, $stD, $condition);

$stateMachine = FiniteStateMachine::createMachine()
    ->addTransition($transitionA_B)
    ->addTransition($transitionA_C)
    ->addTransition($transitionB_D);

$stateMachine->canTransition($stA, $stB);  // returns true
$stateMachine->canTransition($stA, $stC);  // returns true
$stateMachine->canTransition($stA, $stD);  // returns false
$stateMachine->canTransition($stB, $stA);  // returns false
$stateMachine->canTransition($stB, $stD);  // returns false
$stateMachine->canTransition($stB, $stD, ["some_info"]); // returns true
$stateMachine->canTransition($stC, $stD); //returns false

$stateMachine->isInitialState($stA); // returns true
$stateMachine->isInitialState($stB); // returns false
$stateMachine->isFinalState($stA); // returns false
$stateMachine->isFinalState($stC); // returns true
$stateMachine->isFinalState($stD); // returns true

$condition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return !is_null($data);
    }
};

$stateMachine = FiniteStateMachine::createMachine(
    [
        ['A', 'B'],
        ['A', 'C'],
        ['B', 'D', $condition]
    ]
);

use ByJG\StateMachine\TransitionConditionInterface;

// States:
$stInitial = new State("__VOID__");
$stInStock = new State("IN_STOCK");
$stLastUnits = new State("LAST_UNITS");
$stOutOfStock = new State("OUT_OF_STOCK");

// Transition conditions:
$inStockCondition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return $data["qty"] >= $data["min_stock"];
    }
};

$lastUnitsCondition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return $data["qty"] > 0 && $data["qty"] < $data["min_stock"];
    }
};

$outOfStockCondition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return $data["qty"] == 0;
    }
};

// Transitions:
$transitionInStock = Transition::create($stInitial, $stInStock, $inStockCondition);
$transitionLastUnits = Transition::create($stInitial, $stLastUnits, $lastUnitsCondition);
$transitionOutOfStock = Transition::create($stInitial, $stOutOfStock, $outOfStockCondition);

// Create the Machine:
$stateMachine = FiniteStateMachine::createMachine()
    ->addTransition($transitionInStock)
    ->addTransition($transitionLastUnits)
    ->addTransition($transitionOutOfStock);

$stateMachine->autoTransitionFrom($stInitial, ["qty" => 10, "min_stock" => 20]); // returns LAST_UNITS
$stateMachine->autoTransitionFrom($stInitial, ["qty" => 30, "min_stock" => 20]); // returns IN_STOCK
$stateMachine->autoTransitionFrom($stInitial, ["qty" => 0, "min_stock" => 20]); // returns OUT_OF_STOCK

use ByJG\StateMachine\StateActionInterface;

$action = new class implements StateActionInterface {
    public function execute(?array $data): void {
        // Execute some operation with the data
        // This is the STATE action, not the transition condition
        echo "Processing state with: " . json_encode($data);
    }
};

$stN = new State('SOMESTATE', $action);

// After autoTransition returns the $stN state object
// You can execute its action:

$resultState = $stateMachine->autoTransitionFrom('STATE', [... data ...]);
$resultState->process(); // This will run the state's action with the data

$condition = new class implements TransitionConditionInterface {
    public function canTransition(?array $data): bool {
        return isset($data["approved"]) && $data["approved"] === true;
    }
};

$transitions = Transition::createMultiple([$from1, $from2], $to, $condition);

$machine = FiniteStateMachine::createMachine()
    ->addTransitions($transitions);

$stateMachine->possibleTransitions($stA);

// Return null if doesn't exist, otherwise return the object State
$state = $stateMachine->state('OUT_OF_STOCK');