php - WordPress カスタムフィールドをデータベースに保存する

Question

カスタム フィールドをメディア ライブラリに追加するための非常に単純なプラグインを作成しましたが、データベースの wp_postmeta テーブルには、pdf のメタ データがないことが示されています。meta_value 列でシリアル化されたメタデータを取得することになっています。以下のプラグインは間違っていますか? プラグインは、カスタム フィールドの追加を実現しますが、データベースへの保存は実現しません。

meta_id post_id     meta_value
552   356          a:0:{}
551   356   

プラグイン コード

  <?php
    /*
    Plugin Name: Media Library Fields
    Plugin URI: http://mhmintranet
    Description: The plugin adds additional fields to the media library
    Version: 1.0
    Author: me
    Author URI: Metropolitan State Hospital http://mhmintranet
    License: GPL2
    */
    function GetCustomFormFields($form_fields, $post)
    {
        $form_fields['RevisionDate'] = array(
                
                'label' => 'Revision Date',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_RevisionDate',true),
                'helps' => 'This is the date the document was revised last'
                );
                
        $form_fields['ADTitle'] = array(
                
                'label' => 'AD Title',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_ADTitle',true),
                'helps' => 'Administrative Directive Title'
                );
        $form_fields['AdNumber'] = array(
                
                'label' => 'AD Number',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_AdNumber',true),
                'helps' => 'Administrative Directive Title'
                );
        
        return $form_fields;
    }
    add_filter("attachment_fields_to_edit", "GetCustomFormFields", null, 2);  
    
    function SaveCustomFormFields($post,$attachment)
    {
        if(isset($attachment['RevisionDate']))
        {
            update_post_meta($post['ID'], '_RevisionDate', $attachment['RevisionDate']);  
        }
    if(isset($attachment['ADTitle']))
        {
            update_post_meta($post['ID'], '_ADTitle', $attachment['ADTitle']);  
        }
    if(isset($attachment['AdNumber']))
        {
            update_post_meta($post['ID'], '_AdNumber', $attachment['AdNumber']);  
        }
        return $post;
    }
    add_filter('attachment_fields_to_save','SaveCustomFormFields');
    
    ?>

Answer 1

add_filter('attachment_fields_to_save','SaveCustomFormFields',null,2); がありませんでした。

 <?php
    /*
    Plugin Name: Media Library Fields
    Plugin URI: http://mhmintranet
    Description: The plugin adds additional fields to the media library
    Version: 1.0
    Author: Jose Velez
    Author URI: Metropolitan State Hospital http://mhmintranet
    License: GPL2
    */

    //Function used 
    /*get_post_meta :http://codex.wordpress.org/Function_Reference/get_post_meta

    attachment_fields_to_edit  and attachment_fields_to_save is a hook located wp-admin/includes/media.php
    To learn more: 
    http://net.tutsplus.com/tutorials/wordpress/creating-custom-fields-for-attachments-in-wordpress/
    http://codex.wordpress.org/Plugin_API/Filter_Reference/attachment_fields_to_save

    Weird Wordpress convention : Fields prefixed with an underscore 
    (_RevisionDate) will not be listed in the drop down of available custom fields on the post/page screen; 
    I only need the custom fields in the media library page
    */
    function GetCustomFormFields($form_fields, $post)
    {
        $form_fields['RevisionDate'] = array(

                'label' => 'Revision Date',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_RevisionDate',true),
                'helps' => 'This is the date the document was revised last'
                );

        $form_fields['ADTitle'] = array(

                'label' => 'AD Title',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_ADTitle',true),
                'helps' => 'Administrative Directive Title'
                );
        $form_fields['AdNumber'] = array(

                'label' => 'AD Number',
                'input' => 'text',
                'value' => get_post_meta($posdt->ID, '_AdNumber',true),
                'helps' => 'Administrative Directive Title'
                );

        return $form_fields;
    }
    add_filter("attachment_fields_to_edit", "GetCustomFormFields", null, 2);  

    function SaveCustomFormFields($post,$attachment)
    {
        if(isset($attachment['RevisionDate']))
        {
            update_post_meta($post['ID'], '_RevisionDate', $attachment['RevisionDate']);  
        }
    if(isset($attachment['ADTitle']))
        {
            update_post_meta($post['ID'], '_ADTitle', $attachment['ADTitle']);  
        }
    if(isset($attachment['AdNumber']))
        {
            update_post_meta($post['ID'], '_AdNumber', $attachment['AdNumber']);  
        }
        return $post;
    }
    add_filter('attachment_fields_to_save','SaveCustomFormFields',null,2);

    ?>