Is there a way to chain php methods while also returning something?

Question

I have a recursively defined function called getPropertyValue($object, $property) that returns false if $property doesn't exist at an arbitrary depth into $object, and the value corresponding to the first $property found inside $object otherwise. It is essentially a generalized version of PHP's built-in function property_exists()

I want to make this method chainable, and I know that to do this, I would simply return a reference to the class instance ($this) in the method, but I am already returning, as I mentioned above, the value corresponding to the first $property found inside $object.

How can I make this method chainable while still returning this value? I'm thinking a possibility is to return an object containing both $this and the value of that property/false, if it is found/not found, respectively. Is this a viable approach? What would be the best way to achieve chainability in this context?

Thanks very much.

Answer 1

This kind of API doesn't really work when you want to return data.

It can be a convenience for building complex objects where numerous methods can be executed with less boilerplate code. The methods tend to be named descriptively, giving a good idea of what being done.

An example is the 'query builder' pattern, building the SQL statement via chained methods.

$sql = $qb->select()->from('table')->where()->field('foo')->equals('bar');

Don't be fooled however, this is just saving you from using setters.

$qb->setSelect();
$qb->setFrom('table');
$qb->setField('foo');  
$qb->setEquals('bar');

Obvious you are not creating a query builder, and there are different implementations of the same API, however the key is they all add data to the object rather than return it.

Answer 2

you can return multiple values by putting them into an array:

return array($value,$this); // so you return both.