Broken Image Author Meta Plugin

<?php
/*
Plugin Name: MarkMediaMeta
Description: A custom plugin for mrwweb.com to add media rights information. Forever indebted to http://www.billerickson.net/wordpress-add-custom-fields-media-gallery/.
Version: 0.5
Author: Mark Root-Wiley
Author URI: http://mrwweb.com
*/

/**
 * Add Author Name, Author URL, License Text, and License URL to media library.
 *
 * @param $form_fields array, fields to include in attachment form
 * @param $post object, attachment record in database
 * @return $form_fields, modified form fields
 */

add_filter( 'attachment_fields_to_edit', 'mrw_media_fields', 10, 2 );

function mrw_media_fields( $form_fields, $post ) {

    $form_fields['mrw-creator-name'] = array(
        'label' => 'Creator Name',
        'input' => 'text',
        'value' => get_post_meta( $post->ID, 'mrw_creator_name', true ),
        'helps' => 'Name of the content creator.'
    );

    $form_fields['mrw-creator-url'] = array(
        'label' => 'Creator URL',
        'input' => 'text',
        'value' => get_post_meta( $post->ID, 'mrw_creator_url', true ),
        'helps' => 'Link to the content creator.'
    );

    $form_fields['mrw-license-name'] = array(
        'label' => 'License Name',
        'input' => 'text',
        'value' => get_post_meta( $post->ID, 'mrw_license_name', true ),
        'helps' => 'Media copyright license.'
    );

    $form_fields['mrw-license-url'] = array(
        'label' => 'License URL',
        'input' => 'text',
        'value' => get_post_meta( $post->ID, 'mrw_license_url', true ),
        'helps' => 'URL for the media copyright license.'
    );

    return $form_fields;
}


/**
 * Save values to Author Name, Author URL, License Text, and License URL to media library.
 *
 * @param $post array, the post data for database
 * @param $attachment array, attachment fields from $_POST form
 * @return $post array, modified post data
 */

add_filter( 'attachment_fields_to_save', 'mrw_media_fields_save', 10, 2 );

function mrw_media_fields_save( $post, $attachment ) {

    if( isset( $attachment['mrw-creator-name'] ) )
        update_post_meta( $post['ID'], 'mrw_creator_name', $attachment['mrw-creator-name'] );

    if( isset( $attachment['mrw-creator-url'] ) )
        update_post_meta( $post['ID'], 'mrw_creator_url', $attachment['mrw-creator-url'] );

    if( isset( $attachment['mrw-license-name'] ) )
        update_post_meta( $post['ID'], 'mrw_license_name', $attachment['mrw-license-name'] );

    if( isset( $attachment['mrw-license-url'] ) )
        update_post_meta( $post['ID'], 'mrw_license_url', $attachment['mrw-license-url'] );

    return $post;
}


/**
 * Filter to get caption and append image information to it.
 *
 * @return text HTML content describing with media attribution
 **/

add_filter('get_image_tag', 'mrw_append_media_credit', 20, 2);

function mrw_append_media_credit( $html, $id ) {

    $mrw_media_string = mrw_media_credit_string( $id );

    $html = $html . $mrw_media_string;

    return $html;

}

/**
 * Append creator stuff to attachment pages.
 **/

add_filter('the_content', 'mrw_append_attachment_credit', 20);

function mrw_append_attachment_credit( $content ) {

    if ( is_attachment() ) {

        global $post;

        $mrw_media_string = mrw_media_credit_string( $post->ID );

        $content = $content . $mrw_media_string;

    }

    return $content;

}

/**
 * Function to lookup media creator fields and put them together.
 *
 * returns an html string with creator name and license name links.
 **/

function mrw_media_credit_string( $mrw_media_id ) {

    $mrw_name = get_post_meta( $mrw_media_id, 'mrw_creator_name', true );
    $mrw_name_url = get_post_meta( $mrw_media_id, 'mrw_creator_url', true );
    $mrw_license_name = get_post_meta( $mrw_media_id, 'mrw_license_name', true );
    $mrw_license_url = get_post_meta( $mrw_media_id, 'mrw_license_url', true );

    $mrw_creator = null;
    if( $mrw_name ) {
        if( $mrw_name_url ) {
            $mrw_creator = ' <a href="' . $mrw_name_url . '">' . $mrw_name . '</a>.';
        } else {
            $mrw_creator = ' ' . $mrw_name;
        }
    }

    $mrw_license = null;
    if( $mrw_license_name ) {
        if( $mrw_license_url ) {
            $mrw_license = ' <a href="' . $mrw_license_url . '">' . $mrw_license_name . '</a>.';
        } else {
            $mrw_license = ' ' . $mrw_license_name;
        }
    }

    return '<span class="mrw-media-attr">Credit:' . $mrw_creator . $mrw_license . '</span>';

}

?>