Unattach 1.0.3

<?php
/*************************************************************************
Plugin Name:  Unattach
Plugin URI:   http://outlandishideas.co.uk/blog/2011/03/unattach/
Description:  Allows detaching images and other media from posts, pages and other content types.
Version:      1.0.3
Author:       tamlyn, Ov3rfly (1.0.2 & 1.0.3 changes)
**************************************************************************/

//filter to add button to media library UI
function unattach_media_row_action( $actions, $post ) {
    // 1.0.3: only add action if user can edit media and parent
    if ( current_user_can( 'edit_post', $post->ID ) && $post->post_parent && current_user_can( 'edit_post', $post->post_parent ) ) {
        // 1.0.3: options.php as target page
        // 1.0.2: add nonce to fix CSRF
        $url = wp_nonce_url( admin_url('options.php?page=unattach&noheader=true&id=' . $post->ID ), 'unattach' );
        // 1.0.3: add current page and searchterm as param
        if ( !empty( $_REQUEST['paged'] ) ) {
            $pagenum = (int)$_REQUEST['paged'];
            if ( $pagenum > 1 ) {
                $url = add_query_arg( 'paged', $pagenum, $url );
            }
        }
        if ( !empty( $_REQUEST['s'] ) ) {
            $url = add_query_arg( 's', $_REQUEST['s'], $url );
        }
        // 1.0.2: localized strings
        $actions['unattach'] = '<a href="' . esc_url( $url ) . '" title="' . __( 'Unattach this media item.', 'unattach' ) . '">' . __( 'Unattach', 'unattach' ) . '</a>';
    }

    return $actions;
}

//action to set post_parent to 0 on attachment
function unattach_do_it() {
    // 1.0.2: check nonce to fix CSRF
    check_admin_referer( 'unattach' );

    global $wpdb;
    if ( !empty($_REQUEST['id'] ) ) {
        // 1.0.2: cast id to int
        $id = (int)$_REQUEST['id'];
        // 1.0.3: check if user can edit media
        if ( current_user_can( 'edit_post', $id ) ) {
            $wpdb->update($wpdb->posts, array('post_parent'=>0), array('id'=>$id, 'post_type'=>'attachment'));
        }
    }

    $url = 'upload.php';
    // 1.0.3: add current page and searchterm as param
    if ( !empty( $_REQUEST['paged'] ) ) {
        $pagenum = (int)$_REQUEST['paged'];
        if ( $pagenum > 1 ) {
            $url = add_query_arg( 'paged', $pagenum, $url );
        }
    }
    if ( !empty( $_REQUEST['s'] ) ) {
        $url = add_query_arg( 's', $_REQUEST['s'], $url );
    }

    wp_redirect( admin_url( $url ) );
    exit;
}

//set it up
add_action( 'admin_menu', 'unattach_init' );
function unattach_init() {
    // 1.0.2: add filter for capability
    $capability = apply_filters( 'unattach_capability', 'upload_files' );
    if ( current_user_can( $capability ) ) {
        add_filter('media_row_actions',  'unattach_media_row_action', 10, 2);
        // 1.0.3: use null instead tools.php
        add_submenu_page( null, 'Unattach', 'Unattach', $capability, 'unattach', 'unattach_do_it' );
    }
}

/*
// example to restrict access via capability in functions.php
// see also http://codex.wordpress.org/Roles_and_Capabilities
function my_unattach_capability( $capability ) {
    return 'administrator';
}
add_filter( 'unattach_capability', 'my_unattach_capability' );
*/

// 1.0.2: add translation possibility
function unattach_load_textdomain() {
    load_plugin_textdomain( 'unattach', false, dirname( plugin_basename( __FILE__ ) ) . '/lang/' );
}
add_action( 'plugins_loaded', 'unattach_load_textdomain' );

// 1.0.3 complete package with language files: http://www.wikisend.com/download/647230/unattach.zip