Code Smell 55 - Object Orgy

If you see your objects as data holders you will violate their encapsulation, but you shouldn't, as in real life, you should always ask for consent.

9 March, 2023

Contributors

Maxi Contieri

@mcsee

If you see your objects as data holders you will violate their encapsulation, but you shouldn't, as in real life, you should always ask for consent.

TL;DR: Don't mess with other object's data.

Problems

Information Hiding Violation
Encapsulation Violation
Coupling

Solutions

Couple to interfaces and behavior, never data.

Sample Code

Wrong

<?

final class Point {
    public $x;
    public $y;
}

final class DistanceCalculator {
    function distanceBetween(Point $origin, Point $destination) {
        return sqrt((($destination->x - $origin->x) ^ 2) + (($destination->y - $origin->y) ^ 2));
    }
}

Right

<?

final class Point {
    private $rho;
    private $theta;

    public function x() {
        return $this->rho * cos($this->theta);
    }

    public function y() {
        return $this->rho * sin($this->theta);
    }
}

final class DistanceCalculator {
    function distanceBetween(Point $origin, Point $destination) {

        return sqrt((($destination->x() - $origin->x() ^ 2) + (($destination->y() - $origin->y()) ^ 2)));
    }

}

Detection

You can set your linters to warn you of public attributes, setters, and getters usage, and discourage them.

Conclusion

If your classes are polluted with setters, getters, and public methods you will certainly have ways to couple to their accidental implementation.

Also Known as

Inappropriate intimacy

Relations

Code Smell 01 - Anemic Models

Code Smell 28 - Setters

More Info

Credits

Picture by Nicolas Poussin

A data structure is just a stupid programming language.

Bill Gosper

Software Engineering Great Quotes

This article is part of the CodeSmell Series.

How to Find the Stinky Parts of your Code