CODEWITHSUNDEEP
phpdesign-patternsregistry
Mandela
Mandela

Reputation: 31

Registry Php Example

I have this code which I came across in reading and when I view it in a browser it does not cause any errors. My question is how can the class call $this->registry without the property being set. In other words what is the $this->registry within the function referring to?

class Template{

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

}

this is how I instantiate the classes.

<?php
include 'registry.class.php';
include 'template.class.php';
$registry = new Registry();
$template = new Template($registry);
?>

Upvotes: 3

Views: 447

Answers (2)

Darren
Darren

Reputation: 13128

You're basically referencing the Registry object. Look at it this way:

function __construct(Registry $registry) {
    $this->registry = $registry;
}

Referencing $this->registry is calling the Templates "copy" of the Registry object. So when you pass the $registry object to the Template with:

$template = new Template($registry);

You're basically "giving" the Template class its own $registry object. I've used a similar registry before. Where you can instantiate it like this:

$registry = new registry();
$registry->template = new template($registry);

Allowing you to access Template methods/vars/etc via the registry:

$registry->template->method();

There will be somebody who can explain the exact happenings a lot better than I can right now, but remember, the best way to learn is by trial and error. Learn from your mistakes :-)

As per the comments, your Template class should look like this:

class Template {

    var $registry;

    function __construct($registry) {
        $this->registry = $registry;
    }
}

That will allow you to access it throughout the class.

Example:

function link($url){
    return $this->registry->site->link($url);
}

The above is a fictional function and the reference to site is also fictional but shows how you could use this class and/or registry.

Upvotes: 1

myhonestopinion
myhonestopinion

Reputation: 51

-> is for accessing object fields. So you are setting an object field called registry in the constructor for Template to the value of $registry, which is passed to the constructor. Think for this->registry as referring to a variable registry in the object Template.

Upvotes: 0

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