CODEWITHSUNDEEP
phpoopinheritanceparenttraversal
Question Mark
Question Mark

Reputation: 3606

Get a PHP object's ancestors in the inheritance tree

I have an object and want to list all parent classes up until stdClass or whatever.

I have added a polymorphic field to my database table (say categories) and want to automate my finder method so that super classes are also returned, this way i can jump into the inheritance tree at a point i know not necessarily the final subclass:

FoodCategory::find_by_id(10) === Category::find_by_id(10)

SELECT * FROM categories WHERE ..... AND type IN ('FoodCategory', 'Category');

Roughly i guess:

function get_class_lineage($object){
    $class = get_parent_class($object);
    $lineage = array();
    while($class != 'stdClass'){
        $dummy_object = new $class();
        $lineage[] = $class = get_parent_class($dummy_object);
    }

    return $lineage;
}

But this instantiates an object, does anyone know how to achieve this without?

Thanks for any input, i feel like i'm missing something obvious here.

Upvotes: 6

Views: 4938

Answers (3)

Question Mark
Question Mark

Reputation: 3606

After being pointed to the duplicate question i have gone for:

function get_class_lineage($object){
    $class_name = get_class($object);
    $parents = array_values(class_parents($class_name));
    return array_merge(array($class_name), $parents);
}

The class_parents function from the standard library was the obvious thing i was overlooking.

I thought Reflection was overkill for this simple task.

Upvotes: 9

Christopher Manning
Christopher Manning

Reputation: 4557

Using Reflection

$class = new ReflectionClass($object);

$lineage = array();

while ($class = $class->getParentClass()) {
    $lineage[] = $class->getName();
}

echo "Lineage: " . implode(", ", $lineage);

ReflectionClass accepts either the name of the class or an object.

Upvotes: 13

KingCrunch
KingCrunch

Reputation: 131891

As you can read at manual you can also give a classname as a string to the function.

$class = get_class($this);
$lineage = array();
do {
  $lineage[] = $class;
  $class = get_parent_class($class);
} while ($class != 'stdClass');

Here index 0 is the classname of the object itself:

Upvotes: 2

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