PHP: Access nested object properties via dot notation

Question

What is a simple method to access nested properties of an object via a "dot notion" string?

For example:

#..........................Classes..........................

class Colour            |   class Eye       |   class Person
{                       |   {               |   {
    $hexValue = #36ff00 |       $colour;    |       $eyes;
}                       |   }               |   }

#..........................Example..........................

$john = new Person;

$eyes = [new Eye, new Eye];

$eyes[0]->color = new Colour;

$eyes[1]->color = new Colour;

$john->eyes = [new Eye, new Eye];

#..........................Question..........................

# How can we do something like this?

$eyeColour = Helper::dot($john, 'eyes[0].colour.hexValue'); 

Answer 1

There is no simple method to do this. You'll have to parse the path string and then reach the desired value step by step.

Checkout the Symfony PropertyAccess Component. It can be used as a standalone library without the rest of the framework.

use Symfony\Component\PropertyAccess\PropertyAccess;

$accessor = PropertyAccess::createPropertyAccessor();

$eyeColour = $accessor->getValue($john, 'eyes[0].colour.hexValue');