No longer return $this on Collection __set() method

[neildaniels]

Explanation

This PR changes the behavior of __set() methods to no longer return $this. Instead there is no return value.

A return type was never formalized in code, but was defined in the DocBlock for Kirby\Toolkit\Collection.

Although Kirby\Toolkit\Collection returns $this, the subclass Kirby\Cms\Collection does not return anything.

kirby/src/Cms/Collection.php

Lines 67 to 78 in e15a4ea

	/**
	* Internal setter for each object in the Collection.
	* This takes care of Component validation and of setting
	* the collection prop on each object correctly.
	*
	* @param string $id
	* @param object $object
	*/
	public function __set(string $id, $object)
	{
	$this->data[$id] = $object;
	}

The Kirby\Cms\Pages class extends Kirby\Cms\Collection and does not override __set() so it therefor also returns nothing.

Kirby\Cms\Structure also extends Kirby\Cms\Collection. It attempts to return a value in its reimplementation of __set(), but because it's returning parent::__set() and the Kirby\Cms\Collection implementation does not return anything, it's effectively returning void.

The formal definition of the magic method __set() has a void return type.

public __set(string $name, mixed $value): void

Additionally, the PHP Docs also say that a return a type on __set() is always ignored. None of their examples return a value either.

Note:
The return value of __set() is ignored because of the way PHP processes the assignment operator. Similarly, __get() is never called when chaining assignments together like this:
$a = $obj->b = 8;

This PR …

Refactoring

• The $collection->__set() methods consistently no longer return the class instance to match PHP's definition for this method.

Breaking changes

This is technically a breaking change: the return type is ignored, but only for usage such as $collection->foo = $example;. Usage by calling the function literally still would return a value $collection->__set('foo', $example);.

However, the impact of this breaking change should be minimal, considering that Kirby\Cms\Collection never returned a value anyways.

Ready?

• Unit tests for fixed bug/feature
• In-code documentation (wherever needed)
• Tests and checks all pass

For review team

• Add changes to release notes draft in Notion
• Add to website docs release checklist (if needed)

[distantnative]

@lukasbestle what do you think? maybe this could go into 3.7.1 since it is more like fixing a bug than breaking change?

[lukasbestle]

I've added void type hints for consistency with the formal definition.