Metadata

ID: php-code-style/no-this-static

Language: PHP

Severity: Error

Category: Error Prone

Description

In PHP, $this is a special variable that is used to reference the current object. However, static methods are not associated with an object, but with a class. Therefore, $this is not available within a static method.

Ignoring this rule and attempting to use $this in a static method results in a fatal error because PHP cannot resolve $this without an instance of the class. It is critical to ensure that $this is not used in a static context to prevent such fatal errors.

To follow this rule, you should only use $this in non-static methods where it will refer to the current object instance. If you need to use a method or property in a static method, consider making that method or property static as well. For example, if you have a property that you need to access in a static method, you can declare it as public static $property, and then access it in the static method using self::$property instead of $this->property.

Non-Compliant Code Examples

<?php
class Foo {
    public $debug;

    static function print() {
        if ($this->debug) {
            echo "Testing";
        }
    }
}

Compliant Code Examples

<?php
class Foo {
    public $debug;

    public function print() {
        if ($this->debug) {
            echo "Testing";
        }
    }
}