如何处理对作为另一个对象的私有属性的对象的方法调用？

Question

I have two classes, the Page class and the Template class. A page has a template associated with it, so it stores an object of the Template class as one of it's properties.

Here is my issue. These calsses are used in templating a page. If I want to include the template file, I would call include $Template->view();. However, since this object is a property of the a Page object, I have to call include $Page->template->view();.

This sticks me in the middle of two problems.

1. If I leave the $Page->template variable public, it could be overwritten at any point with something that isn't a Template object.
2. Make the $Page->template variable private, and I can no longer access it as I want to by calling $Page->template->method();.

From my point of view, the only option is wrapper methods in the Page class, such as $Page->templateView();.

I am the only one coding this, so option 1 is acceptable, as I will simply no overwrite it, but I wonder if there's a better way. If only there were properties that could be used publicly but not modified publicly.

Is there another choice for handling this type of thing?
Am I over thinking this or missing something?

Answer 1

You can either:

a) Make a public accessor method and call it like so:

class Page
{
    private $template;

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

// call it like this
$page_object->template()->method();

b) If you don't like using "template()" instead of "template", you can take advantage of magic methods:

class Page
{
    private $mTemplate;

    public function __get($name)
    {
        if ($name == 'template')
            return $this->mTemplate;
    }
}

// call it like this
$page_object->template->method();