PM_Uploader を利用したバナーウィジェット（WordPress 3.5以降）

class-pm-widget-banner.php

<?php
if ( ! class_exists( 'PM_Widget_Banner' ) ) {

add_action( 'widgets_init', create_function( '', 'new PM_Uploader; register_widget("PM_Widget_Banner");' ) );

require_once( 'class-pm-uploader.php' );

class PM_Widget_Banner extends WP_Widget {

    function __construct() {
        $widget_ops = array( 'description' => 'バナーを表示します' );
        parent::__construct( 'banner', 'バナー', $widget_ops );
    }

    function widget( $args, $instance ) {
        $blank = isset( $instance['blank'] ) ? $instance['blank'] : 0;
        $url   = isset( $instance['url'  ] ) ? $instance['url'  ] : '';
        $alt   = isset( $instance['alt'  ] ) ? $instance['alt'  ] : '';
        $image = isset( $instance['image'] ) 
            ? wp_get_attachment_image( intval( $instance['image'] ), 'full', false, array( 'alt' => $alt ) )
            : '';
            
        if ( 0 !== strpos( $url, 'http') )
            $url = trailingslashit( home_url( $url ) );
            
        printf(
            '<a href="%1$s"%2$s>%3$s</a>'
          , esc_url( $url )
          , ( $blank ? ' target="_blank"' : '' )
          , $image
        );
    }

    function update( $new_instance, $old_instance ) {
        $instance['blank'] = intval( $new_instance['blank'] );
        $instance['image'] = intval( $new_instance['image'] );
        $instance['alt'  ] = strip_tags( $new_instance['alt'] );
        $instance['url'  ] = $new_instance['url'];
        return $instance;
    }

    function form( $instance ) {
        $blank = isset( $instance['blank'] ) ? intval    ( $instance['blank'] ) : 0;
        $image = isset( $instance['image'] ) ? intval    ( $instance['image'] ) : 0;
        $alt   = isset( $instance['alt'  ] ) ? strip_tags( $instance['alt'  ] ) : '';
        $url   = isset( $instance['url'  ] ) ? esc_attr  ( $instance['url'  ] ) : '';
?>
        <div>
            <label for="<?php echo $this->get_field_id('image'); ?>">Image:</label>
            <?php PM_Uploader :: render( array( 'media_id' => $image, 'field_id' => 'image' ), $this ) ?>
        </div>
        <p>
            <label for="<?php echo $this->get_field_id('alt'); ?>">Alt:</label>
            <input type="text" class="widefat" id="<?php echo $this->get_field_id('alt'); ?>" name="<?php echo $this->get_field_name('alt'); ?>" value="<?php echo $alt; ?>" />
        </p>
        <p>
            <label for="<?php echo $this->get_field_id('url'); ?>">URL:</label>
            <input type="text" class="widefat" id="<?php echo $this->get_field_id('url'); ?>" name="<?php echo $this->get_field_name('url'); ?>" value="<?php echo $url; ?>" />
        </p>
        <p>
            <label for="<?php echo $this->get_field_id('blank'); ?>">
            <input type="checkbox" id="<?php echo $this->get_field_id('blank'); ?>" name="<?php echo $this->get_field_name('blank'); ?>" value="1" <?php checked($blank) ?>/> Open New Window</label>
        </p>
<?php
    }
}
}

pm-widget-banner.php

<?php
/*
Plugin Name: Pimp My Banner Widget
Plugin URI: http://pimpmysite.net/archives/137
Description: Banner widget.
Author: Pimp My WP
Author URI: http://pimpmysite.net
Version: 1.0
*/

require_once( 'class-pm-widget-banner.php' );