Why Should You Ditch Global Variables in PHP and Embrace Dependency Injection?

Stop relying on global in PHP: Embrace Dependency Injection for Cleaner Code

Why Should You Avoid Using global?

Global variables create a hidden dependency between functions and the global scope, making your code tightly coupled and difficult to maintain. Dependency injection provides a better approach by explicitly passing required data as parameters.

Example of Dependency Injection

Instead of using global to access configuration in function.php, inject it into the function as an argument:

function conversion($Exec, $Param = array(), $Log = '') {
    // Inject the configuration data as $config
    $config = $this->getConfig();
    $cmd = $config['phppath'] . ' ' . $config['base_path'] . '/' . $Exec;
    // ... (rest of the function)
}

Implementing ConfigManager for Database-Driven Configuration

To load configuration from the database, create a ConfigManager class:

class ConfigManager {

    public function loadConfigurationFromDatabase(Database $db) {
        $result = $db->query('SELECT ...');

        $config = array();
        while ($row = $result->fetchRow()) {
            $config[$row['name']] = $row['value'];
        }

        return $config;
    }

}

Incorporating Other Variables and Dependencies

Use dependency injection to pass any additional variables or dependencies, such as $db, $language, etc., into functions and classes as needed.

Benefits of Dependency Injection

• Decouples code: Makes it easier to reuse and test components independently.
• Increases flexibility: Allows you to swap out dependencies without affecting the rest of the system.
• Enhances maintainability: Reduces the need for global variables and simplifies code structure.
• Improves security: Mitigates potential vulnerabilities by avoiding direct access to global variables.

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