OOP: Display warning and deactivate the plugin if PHP version is less than 5.4

I want to show a notice to the user and deactivate my plugin, using OOP code style, if the user has a PHP version less than 5.4.

The code works fine when I create my plugin using non-OOP. It shows an warning to the user and deactivate the plugin and prevents user from activating the plugin.

Working code is given below:

Non-OOP

// check for required php version and deactivate the plugin if php version is less.
 if ( version_compare( PHP_VERSION, '5.4', '<' )) {
add_action( 'admin_notices', 'show_notice', 100 );
function show_notice() { ?>
    <div class="error"> <p>
            <?php
            echo 'MyPluginName requires minimum PHP 5.4 to function properly. Please upgrade PHP version. The Plugin has been auto-deactivated.. You have PHP version '.PHP_VERSION;
            ?>
        </p></div>
    <?php
    if ( isset( $_GET['activate'] ) ) {
        unset( $_GET['activate'] );
    }
}

// deactivate the plugin because required php version is less.
add_action( 'admin_init', 'MyPluginName_deactivate_self' );
function MyPluginName_deactivate_self() {
    deactivate_plugins(plugin_basename( __FILE__ ) );
}
return;
}

However, this code does not work when I develop my plugin using Object Oriented Programing. I have tried the following:

Attempt #1

// check for required php version and deactivate the plugin if php version is less.
 if ( version_compare( PHP_VERSION, '5.4', '<' )) {
add_action( 'admin_notices', 'show_notice', 100 );
function show_notice() { ?>
    <div class="error"> <p>
            <?php
            echo 'MyPluginName requires minimum PHP 5.4 to function properly. Please upgrade PHP version. The Plugin has been auto-deactivated.. You have PHP version '.PHP_VERSION;
            ?>
        </p></div>
    <?php
    if ( isset( $_GET['activate'] ) ) {
        unset( $_GET['activate'] );
    }
}

// deactivate the plugin because required php version is less.
add_action( 'admin_init', 'MyPluginName_deactivate_self' );
function MyPluginName_deactivate_self() {
    deactivate_plugins(plugin_basename( __FILE__ ) );
}
return;
}


if ( ! class_exists('MyPluginClass') ) :
class MyPluginClass {
function __construct( ){
        //enqueue scripts/styles only for front-end
        add_action('template_redirect', [$this, 'user_enqueue_scripts']);
        //enqueue scripts and style only for admin panel
        add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );

        }
}

endif;
$MyPlugin = new MyPluginClass();

Attempt #2

if ( ! class_exists('MyPluginClass') ) :
    class MyPluginClass {
        function __construct( ){}

        public function check_php_version (){
            // check for required php version and deactivate the plugin if php version is less.
            if ( version_compare( PHP_VERSION, '5.4', '<' )) {
                add_action( 'admin_notices', 'show_notice', 100 );
                function show_notice() { ?>
                    <div class="error"> <p>
                            <?php
                            echo 'MyPluginName requires minimum PHP 5.4 to function properly. Please upgrade PHP version. The Plugin has been auto-deactivated.. You have PHP version '.PHP_VERSION;
                            ?>
                        </p></div>
                    <?php
                    if ( isset( $_GET['activate'] ) ) {
                        unset( $_GET['activate'] );
                    }
                }

                // deactivate the plugin because required php version is less.
                add_action( 'admin_init', 'MyPluginName_deactivate_self' );
                function MyPluginName_deactivate_self() {
                    deactivate_plugins(plugin_basename( __FILE__ ) );
                }
                return;
            }

        }

        public function init() {
            //enqueue scripts/styles only for front-end
            add_action('template_redirect', [$this, 'user_enqueue_scripts']);
            //enqueue scripts and style only for admin panel
            add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );
        }

    }

endif;
$MyPlugin = new MyPluginClass();
$MyPlugin->check_php_version(); // show warning if php version is less than 5.4 and deactivate the plugin
$MyPlugin->init();// initialize the plugin.

Please let me know what I am doing wrong.

Solutions Collecting From Web of "OOP: Display warning and deactivate the plugin if PHP version is less than 5.4"

Here’s my bare-bones template that I use when creating a plugin with OOP. Feel free to modify to your liking.

Template

if ( !defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

if ( !class_exists( 'MyPluginName' ) ) {

    class MyPluginName {

        public function __construct() { // Call your actions/filters here
            add_action( 'tag', array( $this, 'plgn_abbr_function' ), 10, 1 );
        }

        // Begin functions here
        public function plgn_abbr_function() {
            # Code here...
        }
    }
}

if ( class_exists( 'MyPluginName' ) ) { // Instantiate the plugin class
    global $plgn_abbr;
    $plgn_abbr = new MyPluginName();
}

A few things I immediately noticed from skimming through your attempts:

  1. You’d want to call your add_actions under the __construct() and have your functions places outside of that but you’ll need to change the layout of it as well.
  2. You need to update how your add_action layout

    add_action( 'admin_notices', 'show_notice', 100 );

    This structure will not work when utilizing a class, it should be:

    add_action( 'admin_notices', array( $this, 'show_notice' ), 100 );

  3. You’d need to append public before all of your functions like so:

    public function your_code()

Solution

Here’s an update to your code utilizing the template that I gave you above, it’s been tested and works on my end:

if ( !defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

if ( !class_exists( 'MyPluginName' ) ) {

    class MyPluginName {

        public function __construct() {
            // check for required php version and deactivate the plugin if php version is less.
             if ( version_compare( PHP_VERSION, '5.4', '<' ) ) {
                add_action( 'admin_notices', array( $this, 'show_notice' ), 100 );
                add_action( 'admin_init', array( $this, 'MyPluginName_deactivate_self' ) );
                return;
            }
        }

        public function show_notice() {
            ?>
            <div class="error">
                <p><?php echo 'MyPluginName requires minimum PHP 5.4 to function properly. Please upgrade PHP version. The Plugin has been auto-deactivated.. You have PHP version '.PHP_VERSION; ?></p>
            </div>
            <?php
            if ( isset( $_GET['activate'] ) ) {
                unset( $_GET['activate'] );
            }
        }
        public function MyPluginName_deactivate_self() {
            deactivate_plugins( plugin_basename( __FILE__ ) );
        }
    }
}

if ( class_exists( 'MyPluginName' ) ) { // Instantiate the plugin class
    global $plgn_abbr;
    $plgn_abbr = new MyPluginName();
}