Type hinting and multiple constructors

Question

I've been looking into the new features for PHP7 and thought I might begin to ready my project for the new features it introduces, like scalar type hinting.

One of the first problems I encountered was my constructors in various classes. I have some generic contrustors that acts something like this:

public function __construct($data = null) {
    if (is_numeric($data)) {
        $this->controller->createById($data);
    }
    elseif (is_array($data)) {
        $this->controller->createByArray($data);
    }
    elseif (strlen($data) > 0) {
        $this->controller->createByUrl($data);
    }
}

Introducing type hinting for this method will of course throw errors in all directions.

As far as I know PHP7 does not introduce support for multiple constructors. Are there any ways to get around this problem, or is this one of the limitations of the language?

Answer 1

Correct, that's one of the limitations of the language. (and the strlen() > 0 anyway can't be checked via a type. That auto-casts to string… so your method allows everything but "", null and false?)

Generally, there is RFCs in draft to expand the typehinting of PHP in 7.1: https://wiki.php.net/rfc/union_types

That would allow you to write int | float | array | string $data = null.