php-libs/value-states

Extends php-libs/observer to track if a values have been initialized or modified (changed after initialization)

1.3 2021-05-19 07:16 UTC

Requires

• php: ^8.0
• php-libs/observable: ^1.3

MIT

README

PhpLibs\Observable

This package contains a simple set of classes to facilitate adding observers to property methods.

Features

• Execute callable before any value changes

• Execute callable before specific values change

• Execute callable after any value changes

• Execute callable after specific values change

Quick Start

Install

composer require php-libs/observable

Example Class Without Observable Properties

class MyClass
{
    private ?string $propertyA = null;

    private ?string $propertyB = null;

    public function setPropertyA(string $value)
    {
        $this->propertyA = $value;
    }

    public function setPropertyB(string $value)
    {
        $this->propertyB = $value;
    }
}

Example Class With Observable Properties

class MyClass implements \PhpLibs\Observable\BeforeValueChangeObservableInterface
{
    private const PROPERTY_A = 'propertyA';
    private const PROPERTY_B = 'propertyB';
    
    use PhpLibs\Observable\BeforeValueChangeObservableTrait;
    use PhpLibs\Observable\AfterValueChangeObservableTrait;

    private ?string $propertyA = null;

    private ?string $propertyB = null;

    public function setPropertyA(string $value)
    {
        $this->raiseBeforeValueChange(static::PROPERTY_A, $this->propertyA, $value);
        $this->propertyA = $value;
        $this->raiseAfterValueChange(static::PROPERTY_A, $this->propertyA);
    }

    public function setPropertyB(string $value)
    {
        $this->raiseBeforeValueChange(static::PROPERTY_B, $this->propertyB, $value);
        $this->propertyB = $value;
        $this->raiseAfterValueChange(static::PROPERTY_B, $this->propertyB);
    }
}

Full Example

Please see example.php

Which outputs as follows:

propertyA WILL CHANGE from "" to "A-1"
propertyB WILL CHANGE from "" to "B-1"
Begin observing After B Changed
propertyA WILL CHANGE from "A-1" to "A-2"
propertyB WILL CHANGE from "B-1" to "B-2"
propertyB CHANGED to "B-2"
End observing After B Changed
propertyA WILL CHANGE from "A-2" to "A-3"
propertyB WILL CHANGE from "B-2" to "B-3"