如何以零值停止链接方法-PHP

Question

Is it possible to stop chaining methods when a certain link in the chain returns null? For example, I have an array collection like this:

class ArrayCollection {

    protected $array;

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

    public function get($key) {
        try {
            $result = $this->array[$key];
            return $result;
        }
        catch (\Exception $e) {
            return;
        }
    }

}

And then I have an array that gets converted into an Array Collection like this:

$fm = array(
    'template' => 'default',
    'title' => 'Home'
); 

I then try to access a non-existing array key in a template like this:

<?php echo $page->get('fm')->get('test')->get('test'); ?>

I'd like for this last piece of template code to return null, not throw an error. $page->get('fm') returns an array collection, but then if the get method on the array collection returns null, I get a Call to a member function get() on null . If I return an empty array collection, then at the end of the chain I get Object of class ArrayCollection could not be converted to string .

Of course I could wrap my template code in a try ... catch block, but that's not exactly ideal. Maybe I'm going about this the wrong way? Does anyone have a solution?

Answer 1

You are basically trying to call a function on a Null value. This is not possible in my opinion. Best way to tackle this would be a try/ catch block. However, as you have explicitly mentioned that you do not want to use one, you could add validations.

<?php 

if ((!is_null($page)) && (!is_null($page->get('fm'))))
    if(!is_null($page->get('fm')->get('test')))
        echo $page->get('fm')->get('test')->get('test');
    else 
        return null;
else
    return null;

?>