Extending Widgets - Exclude # of posts field from Recent Posts Widget

Question

I am currently using this code to extend WP_Widget_Recent_Posts, but I would like to exclude the field that gives the user the ability to show how many posts they want. I have a set number in my custom query to 4, so this box is useless and I don't want to confuse the user.

class JA_Recent_Work_Widget extends WP_Widget_Recent_Posts {

function __construct() {
    $widget_ops = array('classname' => 'recent_work', 'description' => 'This widget will display 4 of your most recent works in the ART category Jay.');
    $this->WP_Widget('ja_recent_work', 'Jay Alders Recent Work', $widget_ops);
}

function widget($args, $instance) {

    extract( $args );

    if( empty( $instance['number'] ) || ! $number = absint( $instance['number'] ) )
                $number = 10;

    $title = empty($instance['title']) ? ' ' : apply_filters('widget_title', $instance['title']);
        $r = new WP_Query('category_name=art&posts_per_page=4');
        if ($r->have_posts()) :
    ?>
        <?php echo $before_widget; ?>
        <?php if ($title) echo $before_title . $title . $after_title; ?>
        <ul>
        <?php while ($r->have_posts()) : $r->the_post(); ?>
        <li><a href="<?php the_permalink() ?>" title="<?php echo esc_attr(get_the_title()); ?>"><?php echo the_title(); ?></a>
        <a href="<?php the_permalink() ?>"><?php echo the_post_thumbnail(); ?></li>
        <?php endwhile; ?>
        </ul>
        <?php echo $after_widget ?>

    <?php   

        wp_reset_postdata();
        endif;
}
}
 function my_recent_widget_registration() {
   unregister_widget('WP_Widget_Recent_Posts');
   register_widget('JA_Recent_Work_Widget');
}
   add_action('widgets_init', 'my_recent_widget_registration');

Answer 1

You need to add a 'form' method. That is the method that creates the widget form on the backend. In the current default widget, that method looks like this:

function form( $instance ) {
  $title     = isset( $instance['title'] ) ? esc_attr( $instance['title'] ) : '';
  $number    = isset( $instance['number'] ) ? absint( $instance['number'] ) : 5;
  $show_date = isset( $instance['show_date'] ) ? (bool) $instance['show_date'] : false;
  ?>
  <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 $title; ?>" /></p>
  <p><label for="<?php echo $this->get_field_id( 'number' ); ?>"><?php _e( 'Number of posts to show:' ); ?></label>
  <input id="<?php echo $this->get_field_id( 'number' ); ?>" name="<?php echo $this->get_field_name( 'number' ); ?>" type="text" value="<?php echo $number; ?>" size="3" /></p>
  <p><input class="checkbox" type="checkbox" <?php checked( $show_date ); ?> id="<?php echo $this->get_field_id( 'show_date' ); ?>" name="<?php echo $this->get_field_name( 'show_date' ); ?>" />
  <label for="<?php echo $this->get_field_id( 'show_date' ); ?>"><?php _e( 'Display post date?' ); ?></label></p>
  <?php
}

Copy that into your class and remove the line starting with $number and the form field that uses it-- the second <p>.

Also, in your widget method, you can skip the conditional-- if( empty( $instance['number'] ) || ! $number = absint( $instance['number'] ) )-- and just set $number. You don't need to check to see if `$instance['number'] is set. It won't be.