在函数内部重用相同的函数

Question

I've been thinking of the best way to create a dynamically nested

navigation using PHP, and that is to use a function that gets called within the same function to generate the different navigation levels.

I have a database that consists of 3 fields:

• page - Used as a unique identifier for the navigation item
• title - Used to store the title of the navigation item.
• owner - used to store what page this page is associated to. (Parent page)

I'm trying to make the followed menu dynamic

<ul>
    <li><a href="#">Menu 1</a>
        <ul>
            <li><a href="#">Sub Menu 1</a></li>
            <li><a href="#">Sub Menu 2</a></li>
            <li><a href="#">Sub Menu 3</a></li>
            <li><a href="#">Sub Menu 4</a>
                <ul>
                    <li><a href="#">Sub Menu 1 of Sub Menu 4</li>
                    <li><a href="#">Sub Menu 2 of Sub Menu 4</li>
                    <li><a href="#">Sub Menu 3 of Sub Menu 4</li>
                </ul>
            </li>
        </ul>
    </li>
    <li><a href="#">Menu 2</a></li>
</ul>

I'm having issues, as the page crashes upon calling the function again inside the same function, as it creates a continuous loop. How do I prevent this from happening?

Thanks!

Answer 1

A function can simply call itself, by name.

For example: (this is an actual method from one of my classes)

protected function getParentName( $pid ) {

        foreach( $this->input as $a ) {
            if( $pid == $a['id'] ) {
                $this->bc = '<a href="/category/' . $a['id'] . '">' . $a['name'] . '</a> >> ' . $this->bc;
                if( !empty( $a['i_parent'] ) ) {
                    $this->getParentName( $a['i_parent'] );
                }
            }
        }
    }