WordPress不同用户角色可上传的文件类型及大小限制

开放注册的WordPress站点，一般都会根据不同等级的用户角色来赋予不同的权限。文件上传功能就是一个比较常用的功能，那么，如何限制不同用户角色可上传的文件类型及大小呢？

让用户拥有上传文件的权限

默认情况下，有些用户是不允许上传文件的，你可以在主题的 functions.php 添加下面的代码：

//允许用户投稿时上传文件
if ( current_user_can(‘contributor’) && !current_user_can(‘upload_files’) )
add_action(‘admin_init’, ‘allow_contributor_uploads’);
function allow_contributor_uploads() {
$contributor = get_role(‘contributor’);
$contributor->add_cap(‘upload_files’);
}

上面的代码就是给 ‘contributor’ 这个用户角色添加了 ‘upload_files’ （上传文件）的权限。

限制用户上传文件的类型

首先，大家可以先了解一下 WordPress 默认允许上传的文件类型，打开WordPress的 /wp-includes/functions.php 文件，然后搜索 function wp_get_mime_types 定位到那里，你就会看到详细的文件类型：

function wp_get_mime_types() {
// Accepted MIME types are set here as PCRE unless provided.
return apply_filters( ‘mime_types’, array(
// Image formats
‘jpg|jpeg|jpe’ => ‘image/jpeg’,
‘gif’ => ‘image/gif’,
‘png’ => ‘image/png’,
‘bmp’ => ‘image/bmp’,
‘tif|tiff’ => ‘image/tiff’,
‘ico’ => ‘image/x-icon’,
// Video formats
‘asf|asx|wax|wmv|wmx’ => ‘video/asf’,
‘avi’ => ‘video/avi’,
‘divx’ => ‘video/divx’,
‘flv’ => ‘video/x-flv’,
‘mov|qt’ => ‘video/quicktime’,
‘mpeg|mpg|mpe’ => ‘video/mpeg’,
‘mp4|m4v’ => ‘video/mp4’,
‘ogv’ => ‘video/ogg’,
‘mkv’ => ‘video/x-matroska’,
// Text formats
‘txt|asc|c|cc|h’ => ‘text/plain’,
‘csv’ => ‘text/csv’,
‘tsv’ => ‘text/tab-separated-values’,
‘ics’ => ‘text/calendar’,
‘rtx’ => ‘text/richtext’,
‘css’ => ‘text/css’,
‘htm|html’ => ‘text/html’,
// Audio formats
‘mp3|m4a|m4b’ => ‘audio/mpeg’,
‘ra|ram’ => ‘audio/x-realaudio’,
‘wav’ => ‘audio/wav’,
‘ogg|oga’ => ‘audio/ogg’,
‘mid|midi’ => ‘audio/midi’,
‘wma’ => ‘audio/wma’,
‘mka’ => ‘audio/x-matroska’,
// Misc application formats
‘rtf’ => ‘application/rtf’,
‘js’ => ‘application/javascript’,
‘pdf’ => ‘application/pdf’,
‘swf’ => ‘application/x-shockwave-flash’,
‘class’ => ‘application/java’,
‘tar’ => ‘application/x-tar’,
‘zip’ => ‘application/zip’,
‘gz|gzip’ => ‘application/x-gzip’,
‘rar’ => ‘application/rar’,
‘7z’ => ‘application/x-7z-compressed’,
‘exe’ => ‘application/x-msdownload’,
// MS Office formats
‘doc’ => ‘application/msword’,
‘pot|pps|ppt’ => ‘application/vnd.ms-powerpoint’,
‘wri’ => ‘application/vnd.ms-write’,
‘xla|xls|xlt|xlw’ => ‘application/vnd.ms-excel’,
‘mdb’ => ‘application/vnd.ms-access’,
‘mpp’ => ‘application/vnd.ms-project’,
‘docx’ => ‘application/vnd.openxmlformats-officedocument.wordprocessingml.document’,
‘docm’ => ‘application/vnd.ms-word.document.macroEnabled.12’,
‘dotx’ => ‘application/vnd.openxmlformats-officedocument.wordprocessingml.template’,
‘dotm’ => ‘application/vnd.ms-word.template.macroEnabled.12’,
‘xlsx’ => ‘application/vnd.openxmlformats-officedocument.spreadsheetml.sheet’,
‘xlsm’ => ‘application/vnd.ms-excel.sheet.macroEnabled.12’,
‘xlsb’ => ‘application/vnd.ms-excel.sheet.binary.macroEnabled.12’,
‘xltx’ => ‘application/vnd.openxmlformats-officedocument.spreadsheetml.template’,
‘xltm’ => ‘application/vnd.ms-excel.template.macroEnabled.12’,
‘xlam’ => ‘application/vnd.ms-excel.addin.macroEnabled.12’,
‘pptx’ => ‘application/vnd.openxmlformats-officedocument.presentationml.presentation’,
‘pptm’ => ‘application/vnd.ms-powerpoint.presentation.macroEnabled.12’,
‘ppsx’ => ‘application/vnd.openxmlformats-officedocument.presentationml.slideshow’,
‘ppsm’ => ‘application/vnd.ms-powerpoint.slideshow.macroEnabled.12’,
‘potx’ => ‘application/vnd.openxmlformats-officedocument.presentationml.template’,
‘potm’ => ‘application/vnd.ms-powerpoint.template.macroEnabled.12’,
‘ppam’ => ‘application/vnd.ms-powerpoint.addin.macroEnabled.12’,
‘sldx’ => ‘application/vnd.openxmlformats-officedocument.presentationml.slide’,
‘sldm’ => ‘application/vnd.ms-powerpoint.slide.macroEnabled.12’,
‘onetoc|onetoc2|onetmp|onepkg’ => ‘application/onenote’,
// OpenOffice formats
‘odt’ => ‘application/vnd.oasis.opendocument.text’,
‘odp’ => ‘application/vnd.oasis.opendocument.presentation’,
‘ods’ => ‘application/vnd.oasis.opendocument.spreadsheet’,
‘odg’ => ‘application/vnd.oasis.opendocument.graphics’,
‘odc’ => ‘application/vnd.oasis.opendocument.chart’,
‘odb’ => ‘application/vnd.oasis.opendocument.database’,
‘odf’ => ‘application/vnd.oasis.opendocument.formula’,
// WordPerfect formats
‘wp|wpd’ => ‘application/wordperfect’,
) );
}

=> 的前面为格式，后面为格式描述。如果你要禁止上传其中的某些类型，可以参考下面的例子：

将下面的代码添加到主题的 functions.php 文件：

//禁止上传avi和mp4格式的文件
add_filter(‘upload_mimes’, ‘custom_upload_mimes’);
function custom_upload_mimes ( $existing_mimes=array() ) {
unset ($existing_mimes[‘avi’]);
unset ($existing_mimes[‘mp4’]);
return $existing_mimes;
}

如果你还要禁止更多，可以按照 unset ($existing_mimes[‘格式’]); 样例添加即可。

如果你仅仅只需要允许用户上传几种类型而已，还可以通过下面的更简洁的方法，代码添加到主题的 functions.php 文件：

//只允许上传图片文件
add_filter(‘upload_mimes’, ‘custom_upload_mimes’);
function custom_upload_mimes ( $existing_mimes=array() ) {
unset ($existing_mimes);//禁止上传任何文件
$existing_mimes[‘jpg|jpeg|gif|png’]=‘image/image’;//允许用户上传jpg,gif,png文件
return $existing_mimes;
}

如果你还要允许上传其他格式，重复使用 $existing_mimes[‘格式’]=’描述’; 即可。

限制用户上传的文件大小

同样在主题的 functions.php 文件中，添加下面的代码：

//限制上传文件的最大体积
function max_up_size() {
return 500*1024; // 500 kb
}
add_filter(‘upload_size_limit’, ‘max_up_size’);

上面的例子是限制所有用户上传的文件的最大体积为 500 kb （1M =1024*1024）。

注意：主机空间和WordPress本身一般设置了允许上传的文件的最大体积，所以在这里设置需要考虑到这点。

限制不同用户角色可上传的文件类型及大小

其实上面已经给出了限制类型和大小的方法，要根据不同用户角色来限制，只需要添加角色判断代码即可。倡萌举个综合的例子：

//不同用户上传的类型
function custom_upload_mimes ( $existing_mimes=array() ) {
unset ($existing_mimes);//禁止上传任何文件
if( current_user_can( ‘publish_posts’ ) && !current_user_can( ‘publish_pages’ ) ) {
//允许作者（Author）上传的类型
$existing_mimes[‘jpg|jpeg|gif|png’]=‘image/image’;//允许用户上传jpg,gif,png文件
$existing_mimes[‘zip’]=‘application/zip’; //允许用户上传zip压缩包
$existing_mimes[‘pdf’]=‘application/pdf’; //允许用户上传pdf文件
}elseif( current_user_can( ‘edit_posts’ ) && !current_user_can( ‘publish_posts’ ) ) {
//允许投稿者（Contributor）上传的类型
$existing_mimes[‘jpg|jpeg|gif|png’]=‘image/image’;
$existing_mimes[‘pdf’]=‘application/pdf’;
}else{
//其他用户角色上传的类型
$existing_mimes[‘jpg|jpeg|gif|png’]=‘image/image’;
}
return $existing_mimes;
}
//不同用户上传的大小
function max_up_size() {
if( current_user_can( ‘publish_posts’ ) && !current_user_can( ‘publish_pages’ ) ) {
return 2048*1024; // 允许作者（Author）上传 2M
}elseif( current_user_can( ‘edit_posts’ ) && !current_user_can( ‘publish_posts’ ) ) {
return 1024*1024; // 允许投稿者（Contributor）上传 1M
}else{
return 500*1024; // 其他用户角色上传 500 kb
}
}
//只对非管理员执行这两个函数（即：对管理员不生效）
if( !current_user_can( ‘manage_options’ ) ) {
add_filter(‘upload_mimes’, ‘custom_upload_mimes’);
add_filter(‘upload_size_limit’, ‘max_up_size’);
}