Add Language Selection Widget to WordPress Sidebar Easily

Code

// Function to register a language switcher widget
function wp_dudecom_register_language_switcher_widget() {
    register_widget('WP_Dudecom_Language_Switcher_Widget');
}
add_action('widgets_init', 'wp_dudecom_register_language_switcher_widget');

// Define the language switcher widget class
class WP_Dudecom_Language_Switcher_Widget extends WP_Widget {

    // Constructor
    public function __construct() {
        parent::__construct(
            'wp_dudecom_language_switcher_widget',
            __('Language Switcher', 'text_domain'),
            array('description' => __('A widget to switch languages', 'text_domain'))
        );
    }

    // Front-end display of the widget
    public function widget($args, $instance) {
        echo $args['before_widget'];
        if (!empty($instance['title'])) {
            echo $args['before_title'] . apply_filters('widget_title', $instance['title']) . $args['after_title'];
        }
        
        // Display the language switcher
        if (function_exists('pll_the_languages')) {
            pll_the_languages(array('dropdown' => 1));
        } else {
            echo __('Please install and activate Polylang plugin.', 'text_domain');
        }

        echo $args['after_widget'];
    }

    // Back-end widget form
    public function form($instance) {
        $title = !empty($instance['title']) ? $instance['title'] : __('Languages', 'text_domain');
        ?>
        <p>
            <label for="<?php echo esc_attr($this->get_field_id('title')); ?>"><?php _e('Title:', 'text_domain'); ?></label>
            <input class="widefat" id="<?php echo esc_attr($this->get_field_id('title')); ?>" name="<?php echo esc_attr($this->get_field_name('title')); ?>" type="text" value="<?php echo esc_attr($title); ?>">
        </p>
        <?php
    }

    // Sanitize widget form values as they are saved
    public function update($new_instance, $old_instance) {
        $instance = array();
        $instance['title'] = (!empty($new_instance['title'])) ? sanitize_text_field($new_instance['title']) : '';
        return $instance;
    }
}

// Function to enqueue necessary scripts and styles
function wp_dudecom_enqueue_language_switcher_scripts() {
    if (function_exists('pll_the_languages')) {
        wp_enqueue_style('wp-dudecom-language-switcher-style', get_template_directory_uri() . '/css/language-switcher.css');
    }
}
add_action('wp_enqueue_scripts', 'wp_dudecom_enqueue_language_switcher_scripts');