WordPress 技巧：WordPress 后台也使用七牛云存储

我写的 七牛云存储 WordPress 插件只是使用七牛的镜像功能，而 WordPress 后台的图片浏览其实并没有使用七牛的镜像源。很多人，如果 WordPress 后台也要使用七牛图片，怎么处理，于是我写了下面这段代码：

* 注意，我使用的 PHP 闭包函数来处理，所以要新点的版本的 PHP 才行，具体哪个版本支持 PHP 闭包函数，自行查阅一下。

// 因为使用七牛来缩图，WordPress 默认的缩图就没有必要了。 
add_filter('pre_option_thumbnAIl_size_w',   '__return_zero' ); 
add_filter('pre_option_thumbnail_size_h',   '__return_zero' ); 
add_filter('pre_option_medium_size_w',      '__return_zero' ); 
add_filter('pre_option_medium_size_h',      '__return_zero' ); 
add_filter('pre_option_large_size_w',       '__return_zero' ); 
add_filter('pre_option_large_size_h',       '__return_zero' ); 
 
// 因为使用七牛来缩图，也不用生成各种尺寸的数组 
add_filter('intermediate_image_sizes_advanced', function($sizes){ 
    if(isset($sizes['full'])){ 
        return array('full'=>$sizes['full']); 
    }else{ 
        return array(); 
    } 
}); 
 
// 因为使用七牛来缩图，后台图片选择只剩下原图 
add_filter('image_size_names_choose', function($sizes){ 
    if(isset($sizes['full'])){ 
        return array('full'=>$sizes['full']); 
    }else{ 
        return array(); 
    } 
}); 
 
add_filter('upload_dir', function($uploads){ 
    $uploads['url']     = wpjam_get_thumbnail($uploads['url']); 
    $uploads['baseurl'] = wpjam_get_thumbnail($uploads['baseurl']); 
 
    return $uploads; 
}); 
 
add_filter('wp_calculate_image_srcset_meta', '__return_empty_array'); 
 
// 因为使用七牛来缩图，根据各种尺寸，使用七牛的缩图API进行缩图 
add_filter('wp_get_attachment_image_src', function($image, $attachment_id, $size, $icon){ 
    return  wpjam_get_attachment_image_src($attachment_id, $size); 
}, 10 ,4); 
 
 
function wpjam_get_attachment_image_src($attachment_id, $size='full'){ 
 
    $img_url    = wp_get_attachment_url($attachment_id); 
 
    if(emptyempty($img_url)){ 
        return array('', 0, 0, false); 
    } 
 
    $image_meta = wp_get_attachment_metadata( $attachment_id ); 
 
    $crop   = 0; 
 
    if($size == 'thumbnail'){ 
        $crop   = 1; 
        $width  = $height = 150; 
    }elseif($size == 'medium'){ 
        $width  = $height = 300; 
    }elseif($size == 'medium_large'){ 
        $width  = 768; 
        $height = 0; 
    }elseif($size == 'large'){ 
        $width  = $height = 1024; 
    }elseif(is_array($size)){ 
        $width  = $size[0]; 
        $height = $size[1]; 
    } 
 
    if(isset($width) && isset($height)){ 
        $mode       = $crop?'1':'2'; 
        $img_url    = wpjam_get_thumbnail($img_url, compact('width', 'height', 'mode')); 
        $dims       = image_resize_dimensions($image_meta['width'], $image_meta['height'], $width, $height, $crop); 
         
        return array( $img_url, $dims[4], $dims[5],false); 
    }else{ 
        $img_url    = wpjam_get_thumbnail($img_url); 
 
        $image_meta_width   = ($image_meta['width'])??0; 
        $image_meta_height  = ($image_meta['height'])??0; 
 
        return array($img_url, $image_meta_width, $image_meta_height, false); 
    } 
} 
 
// 媒体列表页面，也是使用七牛的缩图API进行缩图 
add_filter('wp_prepare_attachment_for_js', function($response, $attachment, $meta){ 
 
    if(isset($response['sizes'])){ 
        $orientation    = $response['sizes']['full']['orientation']; 
 
        foreach (array('thumbnail', 'medium', 'medium_large', 'large') as $s) { 
            $image_src = wpjam_get_attachment_image_src($attachment->ID, $s); 
 
            $response['sizes'][$s]  = array( 
                'url'           => $image_src[0], 
                'width'         => $image_src[1], 
                'height'        => $image_src[2], 
                'orientation'   => $orientation 
            ); 
        } 
    } 
 
    return $response; 
}, 10, 3);