Ticket #33442: jb-widget-problems.php

<?php 

/*
Plugin Name: JB Widget Problems Demo
Plugin URI: http://johnbeales.com
Description: Shows a problem where Widgets are not displayed if they don't have any $instance data set.
Version: 1.0
Author: John Beales
Author URI: http://johnbeales.com
License: GPL
*/





/**
 * Adds JB_Good_Widget, a widget that displays as expected.
 */
class JB_Good_Widget extends WP_Widget {

        /**
         * Register widget with WordPress.
         */
        function __construct() {
                parent::__construct(
                        'jb_good_widget', // Base ID
                        __( 'Good Widget', 'jb_widgets' ), // Name
                        array( 'description' => __( 'This widget will appear as expected, because we save a title for it.', 'jb_widgets' ), ) // 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 __( 'I am a slightly-configurable widget, because you can set my title. Setting my title makes me visible.', 'jb_widgets' );
                echo $args['after_widget'];
        }

        /**
         * Back-end widget form.
         *
         * @see WP_Widget::form()
         *
         * @param array $instance Previously saved values from database.
         */
        public function form( $instance ) {
                $title = ! empty( $instance['title'] ) ? $instance['title'] : __( 'New title', 'text_domain' );
                ?>
                <p>
                <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label> 
                <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>">
                </p>
                <?php
                var_dump( $instance ); 
        }

        /**
         * 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 Good Widget




/**
 * Adds JB_Bad_Widget, a widget that DOES NOT display as expected
 */
class JB_Bad_Widget extends WP_Widget {

        /**
         * Register widget with WordPress.
         */
        function __construct() {
                parent::__construct(
                        'jb_bad_widget', // Base ID
                        __( 'Bad Widget', 'text_domain' ), // Name
                        array( 'description' => __( 'A widget that should appear, but doesn\'t', 'jb_widgets' ), ) // 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'];
                
                echo $args['before_title'] . apply_filters( 'widget_title', 'Hi there,' ). $args['after_title'];
                
                echo __( 'I am a static widget with no configurable options.', 'jb_widgets' );
                echo $args['after_widget'];
        }

        /**
         * Back-end widget form.
         *
         * @see WP_Widget::form()
         *
         * @param array $instance Previously saved values from database.
         */
        public function form( $instance ) {
                // Nothing, because there are no user-configurable options for this wedget.
                var_dump( $instance );
        }

        /**
         * 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 ) {
                // Nothing, because there are no user-configurable options for this widget.
        }

} // class Good Widget


add_action( 'widgets_init', function() {
        register_widget( 'JB_Good_Widget' );
        register_widget( 'JB_Bad_Widget' );
});