Beginning Object Oriented PHP

[fishcakedev]

I'm trying to learn how to do OOP in PHP, and I have some experience in OOP with C++. So, I decided to make a sample application which involves two classes; Article and ArticleProp.

 

require("ArticleProp.php");

class Article
{
    public function __constructor(ArticleProp $properties)
    {
        $this->properties = $properties;
    }

    public function getProperties()
    {
        return $this->properties;
    }

    public function display()
    {
        print_r($this->properties->getProperties());
    }

    private $properties;
}

 

class ArticleProp
{
    public function __constructor()
    {
    }

    public function addProperty($key, $value)
    {
        $newProperty = array($key => $value);
        $this->properties += $newProperty;
    }

    public function getProperties()
    {
        return $this->properties;
    }

    public function getProperty($key)
    {
        while ($current = current($this->properties))
        {
            if ($key == key($this->properties))
            {
                return $current;
            }
            next($current);
        }
    }

    private $properties = array();
}

 

Article contains an instance of ArticleProp, which is just a wrapper class for a map array that contains properties of an article, like it's title, description, content, time stamp, etc. Here's what I did to test these classes:

 

require("Article.php");

$articleProp = new ArticleProp();
$articleProp->addProperty("title", "Lorem Ipsum Dolor Sit Amet");
$articleProp->addProperty("author", "Fishcake");
$articleProp->addProperty("timestamp", 0);
$articleProp->addProperty("content", "Hello world! Hello world! Hello world! Hello world!");

$article = new Article($articleProp);
$article->display();

 

But it doesn't work. I got an error:

Fatal error: Call to a member function getProperties() on a non-object in C:\xampp\htdocs\xampp\BGT\Article.php on line 28

 

I think the problem is the $properties member of Article is not of ArticleProp type. How do I fix this? Is there some way to declare a variable of a certain type in PHP?

[fishcakedev]

Oops, my bad. I found the mistake. The constructor is supposed to be called "__construct", not "_constructor".

[Mchl]

Yup. It's part of the concept, that method names should be verbs.

 

You might want to take a look at autoload functionality and spl_autoload functions.