Code Smell 55 - Object Orgy
Published
•2 min read
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 for public attributes, setters and getters usage and discourage them.
Tags
- Coupling
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
More info
Credits
Picture by Nicolas Poussin
A data structure is just a stupid programming language.
Bill Gosper
This article is part of the CodeSmell Series.
Last update: 2021/06/14
