CODEWITHSUNDEEP
phpphpdoc
user3413723
user3413723

Reputation: 12213

Change variable type phpDoc

I have a base class that has several classes that inherit from it.

class Pet{
  ...
}
class Dog extends Pet{
   ...
}
class Cat extends Pet{
   ...
}

Then I have another class that consumes this class

class Person{
   /** @var Pet */
   public $pet;
}

These classes are based on some JSON object I will receive. The JSON object could contain a Dog object, or a Cat object. I run a switch statement to figure out which it is at runtime and handle it appropriately. However I would like to have type hinting via PHPDoc for whether it's a cat or dog. I have been unable to figure out how to specify at runtime that it's type has changed from a Pet to a Dog. This didn't work - it still just thinks it's a plain old Pet object.

$pet = json_decode($jsonObj);
if($pet->type == "dog"){
   /** @var Dog */
   $pet = $pet;
}

Any idea how to change the type to a sub-type at runtime with PHPDoc?

Upvotes: 0

Views: 531

Answers (1)

Sebastian Brosch
Sebastian Brosch

Reputation: 43574

You can use the following using instanceof:

if ($pet instanceof Dog) {
    $dog = $pet;
    //now the IDE and runtime knows it is a Dog.
} elseif ($pet instanceof Cat) {
    $cat = $pet;
    //now the IDE and runtime knows it is a Cat.
}

Another way only using the DocBlock:

if ($pet->type === "dog") {

    /** @var Dog $dog */
    $dog = $pet;
    //now the IDE knows it is a Dog (at runtime this could be a Cat too).

} elseif ($pet->type === "cat") {

    /** @var Cat $cat */
    $cat = $pet;
    //now the IDE knows it is a Cat (at runtime this could be a Dog too).

}

Upvotes: 2

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