Ticket #27770: example-widget.php

<?php

namespace Foo;

use WP_Widget;

/**
 * Adds Foo_Widget widget.
 */
class Widget extends WP_Widget {

        /**
         * Register widget with WordPress.
         */
        function __construct() {
                parent::__construct(
                        __CLASS__, // Base ID
                        esc_html__( 'Widget Title', 'text_domain' ), // Name
                        array( 'description' => esc_html__( 'A Foo Widget', 'text_domain' ), ) // Args
                );
        }

        /**
         * Front-end display of widget.
         *
         * @see WP_Widget::widget()
         *
         * @param array $args     Widget arguments.
         * @param array $instance Saved values from database.
         */
        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'];
                }
                echo esc_html__( 'Hello, World!', 'text_domain' );
                echo $args['after_widget'];
        }

        /**
         * Back-end widget form.
         *
         * @see WP_Widget::form()
         *
         * @param array $instance Previously saved values from database.
         *
         * @return bool|string
         */
        public function form( $instance ) {
                $title = ! empty( $instance['title'] ) ? $instance['title'] : esc_html__( 'New title', 'text_domain' );
                ?>
                <p>
                        <label for="<?php echo esc_attr( $this->get_field_id( 'title' ) ); ?>"><?php esc_attr_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

                return true;
        }

        /**
         * Sanitize widget form values as they are saved.
         *
         * @see WP_Widget::update()
         *
         * @param array $new_instance Values just sent to be saved.
         * @param array $old_instance Previously saved values from database.
         *
         * @return array Updated safe values to be saved.
         */
        public function update( $new_instance, $old_instance ) {
                $instance = array();
                $instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';

                return $instance;
        }

} // class Foo_Widget

// register Foo_Widget widget
add_action( 'widgets_init', function () {
        register_widget( new Widget );
} );