widget-related-services.php

<?php

/**
 * Adds SK_Related_Services_Widget widget.
 */
class SK_Related_Services_Widget extends WP_Widget {

    /**
     * Register widget with WordPress.
     */
    function __construct() {
        parent::__construct(
            'related_services', // Base ID
            __( 'Related Services', 'text_domain' ), // Name
            array( 'description' => __( 'Displays the content of Related Services custom field entered in individual Posts', '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 ) {

        global $post;

        $related_services = get_post_meta( $post->ID, 'related_services', true );

        if ( empty( $related_services ) ) {
            return;
        }

        echo $args['before_widget'];
        if ( ! empty( $instance['title'] ) ) {
            echo $args['before_title'] . apply_filters( 'widget_title', $instance['title'] ). $args['after_title'];
        }
        // echo __( 'Hello, World!', 'text_domain' );
        echo $related_services;
        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'] : __( 'Related Services', '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
    }

    /**
     * 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 SK_Related_Services_Widget

// register SK_Related_Services_Widget widget
function sk_register_related_services_widget() {
    register_widget( 'SK_Related_Services_Widget' );
}
add_action( 'widgets_init', 'sk_register_related_services_widget' );