michaelking0/observers

A basic implementation of the observer pattern in PHP

0.1.1 2016-09-10 21:20 UTC

Requires (Dev)

• phpunit/phpunit: ^5.5

MIT

• Michael King

README

Basic PHP observer pattern implementation

Usage

Installation

composer require michaelking0/observers

Making a class Observable (the subject)

In your subject class, implement the MichaelKing0\Observers\Interfaces\ObservableInterface interface. Also, use the trait MichaelKing0\Observers\Traits\ObservableTrait.

<?php

namespace ACME;

use MichaelKing0\Observers\Interfaces\ObservableInterface;
use MichaelKing0\Observers\Traits\ObservableTrait;

class MySubject implements ObservableInterface
{
    use ObservableTrait;
}

Then just add a function that uses the notify method

<?php

namespace ACME;

use MichaelKing0\Observers\Interfaces\ObservableInterface;
use MichaelKing0\Observers\Traits\ObservableTrait;

class MySubject implements ObservableInterface
{
    use ObservableTrait;

    public function save()
    {
        $this->notify('SubjectSaved');
    }
}

This will notify an observers of the event, and pass the event name and current instance as an argument

Creating an Observer

To create an observer, implement the MichaelKing0\Observers\Interfaces\ObservableInterface interface.

<?php

namespace ACME;

use MichaelKing0\Observers\Interfaces\ObservableInterface;
use MichaelKing0\Observers\Interfaces\ObserverInterface;

class MyObserver implements ObserverInterface
{
    public function update($event, ObservableInterface $observable)
    {
        echo 'It works!';
    }
}

Attaching an observer

You can attach an observer to a subject by calling the attach method with the event name, and observer instance i.e.

$subject = new MySubject();
$subject->attach('SubjectSaved', new MyObserver());