UML class diagram

States

Implement the pattern State in yours projects.


Library to create classes following the State pattern in PHP. This can be a cleaner way for an object to change its behavior at runtime without resorting to large monolithic conditional statements and this improve maintainability.

The state pattern is a behavioral software design pattern that implements a state machine in an object-oriented way. With the state pattern, a state machine is implemented by implementing each individual state as a derived class of the state pattern interface, and implementing state transitions by invoking methods defined by the pattern's superclass.

The state pattern can be interpreted as a strategy pattern which is able to switch the current strategy through invocations of methods defined in the pattern's interface.

This pattern is used in computer programming to encapsulate varying behavior for the same object based on its internal state. This can be a cleaner way for an object to change its behavior at runtime without resorting to large monolithic conditional statements and this improve maintainability.

https://en.wikipedia.org/wiki/State_pattern

UML Sequence Diagram

Features


Create several states

Split classes in states to avoid understandable large monolithic statements.

Inherit states and classes

Complete and factorize states thank to inheritance. Stated classes can be also inherited.

Automate states switching

Define states switching rules based on object's properties.

Implement every where

Thanks to traits and interfaces, use this pattern on your existent code. Compatible with Doctrine.

GitHub


Fork the project on GitHub

It is open source! It's hosted, developed, and maintained on GitHub by folks like you.


View GitHub Project

Example



<?php

require 'vendor/autoload.php';

use 
Teknoo\States\Automated\AutomatedInterface;
use 
Teknoo\States\Automated\AutomatedTrait;
use 
Teknoo\States\Automated\Assertion\AssertionInterface;
use 
Teknoo\States\Automated\Assertion\Property;
use 
Teknoo\States\Automated\Assertion\Property\IsEqual;
use 
Teknoo\States\Proxy\ProxyInterface;
use 
Teknoo\States\Proxy\ProxyTrait;
use 
Teknoo\States\State\AbstractState;

class 
English extends AbstractState
{
    public function 
sayHello(): \Closure
    
{
        return function(): 
string {
            return 
'Good morning, '.$this->name;
        };
    }

    public function 
displayDate(): \Closure
    
{
        return function(\
DateTime $now): string {
            return 
$now->format('m d, Y');
        };
    }
}

class 
French extends AbstractState
{
    public function 
sayHello(): \Closure
    
{
        return function(): 
string {
            return 
'Bonjour, '.$this->name;
        };
    }

    public function 
displayDate(): \Closure
    
{
        return function(\
DateTime $now): string {
            return 
$now->format('d m Y');
        };
    }
}

class 
Person implements ProxyInterfaceAutomatedInterface
{
    use 
ProxyTrait,
        
AutomatedTrait;

    
/** @var string */
    
private $name;

    
/** @var string */
    
private $country;

    public function 
__construct()
    {
        
$this->initializeProxy();
    }

    protected static function 
statesListDeclaration(): array
    {
        return [
            
English::class,
            
French::class
        ];
    }

    protected function 
listAssertions(): array
    {
        return [
            (new 
Property([English::class]))
                ->
with('country', new IsEqual('en')),
            (new 
Property([French::class]))
                ->
with('country', new IsEqual('fr')),
        ];
    }

    public function 
setName(string $name): Person
    
{
        
$this->name $name;

        return 
$this;
    }

    public function 
setCountry(string $country): Person
    
{
        
$this->country $country;
        
$this->updateStates();

        return 
$this;
    }
}

$frenchMan = new Person();
$frenchMan->setCountry('fr');
$frenchMan->setName('Roger');

$englishMan = new Person();
$englishMan->setCountry('en');
$englishMan->setName('Richard');

$now = new \DateTime('2016-07-01');

foreach ([
$frenchMan$englishMan] as $man) {
    echo 
$man->sayHello().PHP_EOL;
    echo 
'Date: '.$man->displayDate($now).PHP_EOL;
}

//Display
//Bonjour, Roger
//Date: 01 07 2016
//Good morning, Richard
//Date: 07 01, 2016