所以我正在开发一个自定义的保存后过滤器。它可以处理我用来生成信息的外部API调用，这非常棒。总之，我从API中获取文件信息，下载几个文件，将它们写入目录，压缩并删除它们。一切正常。在这个过程中，我从API中提取数据点，并将它们存储为变量，保存为元字段。我的函数看起来是这样的，减去了所有不需要看到的内容（假设该函数可以工作，但update\\u post\\u meta（）没有启动）。

function stuff_save( $post_id ) {
    $post_type = get_post_type($post_id);
    // If this is just a revision, do nothing.
    if ( wp_is_post_revision( $post_id )|| "animations" != $post_type  )
        return;
   /**code to generate data points**/
        $datapoint = get_post_meta($post_id,custom_field,1);
        $update_var= string_from_API_Call; 
/**uses $datapoint to do a thing; I\'m using this result elsewhere, can echo it, and it\'s successful.**/

        $hat = update_post_meta( $post_id, \'field_name\', $update_var );//returns a value, but that number doesn\'t correspond with any meta key in my database nor does the data save anywhere. 
 }
}add_action( \'save_post\', \'stuff_save\' );

现在，如果我回显$hat，它会返回一个数字，就像它会返回的一样-但是，当我查看post\\u meta表时，该meta键不仅不存在，而且当我刷新脚本时，它也会增加。

有什么帮助吗？

$hat = update_post_meta( $post_id, \'field_name\', $update_var );

/**document  this well or you\'ll drive someone insane in the future.**/ 


$_POST[\'field_name\'] = $update_var;

function stuff_save( $post_id ) {

    $post_type = get_post_type($post_id);

    // If this is just a revision, do nothing.
    if ( wp_is_post_revision( $post_id )|| "animations" != $post_type  ) {
        return;   
    }

    /**code to generate data points**/
    $datapoint = get_post_meta($post_id,custom_field,1);
    $update_var= string_from_API_Call;

    /**uses $datapoint to do a thing; I\'m using this result elsewhere, can echo it, and it\'s successful.**/    
    $hat = update_post_meta( $post_id, \'field_name\', $update_var );//returns a value, but that number doesn\'t correspond with any meta key in my database nor does the data save anywhere.

}

add_action( \'save_post\', \'stuff_save\' );