WordPress函数wp_mime_type_icon()用法 获取MIME类型的图标

描述：

获取MIME类型的图标

用法：

<?php wp_mime_type_icon( $mime ) ?>

参数：

$mime

(string) (可选) MIME类型

默认值: 0

返回值：
(string|boolean)

所有被“钩住”的函数应用到过滤后的值以后，返回过滤后的值。

示例：

<?php
$img = wp_mime_type_icon('video/mp4');
?>
<img src="<?php echo $img ?>" />

源文件：

/**
* Retrieve the icon for a MIME type.
*
* @since 2.1.0
*
* @param string|int $mime MIME type or attachment ID.
* @return string|false Icon, false otherwise.
*/
function wp_mime_type_icon( $mime = 0 ) {
if ( !is_numeric($mime) )
$icon = wp_cache_get("mime_type_icon_$mime");

$post_id = 0;
if ( empty($icon) ) {
$post_mimes = array();
if ( is_numeric($mime) ) {
$mime = (int) $mime;
if ( $post = get_post( $mime ) ) {
$post_id = (int) $post->ID;
$ext = preg_replace('/^.+?.([^.]+)$/', '$1', $post->guid);
if ( !empty($ext) ) {
$post_mimes[] = $ext;
if ( $ext_type = wp_ext2type( $ext ) )
$post_mimes[] = $ext_type;
}
$mime = $post->post_mime_type;
} else {
$mime = 0;
}
} else {
$post_mimes[] = $mime;
}

$icon_files = wp_cache_get('icon_files');

if ( !is_array($icon_files) ) {
/**
* Filter the icon directory path.
*
* @since 2.0.0
*
* @param string $path Icon directory absolute path.
*/
$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/media' );

/**
* Filter the icon directory URI.
*
* @since 2.0.0
*
* @param string $uri Icon directory URI.
*/
$icon_dir_uri = apply_filters( 'icon_dir_uri', includes_url( 'images/media' ) );

/**
* Filter the list of icon directory URIs.
*
* @since 2.5.0
*
* @param array $uris List of icon directory URIs.
*/
$dirs = apply_filters( 'icon_dirs', array( $icon_dir => $icon_dir_uri ) );
$icon_files = array();
while ( $dirs ) {
$keys = array_keys( $dirs );
$dir = array_shift( $keys );
$uri = array_shift($dirs);
if ( $dh = opendir($dir) ) {
while ( false !== $file = readdir($dh) ) {
$file = basename($file);
if ( substr($file, 0, 1) == '.' )
continue;
if ( !in_array(strtolower(substr($file, -4)), array('.png', '.gif', '.jpg') ) ) {
if ( is_dir("$dir/$file") )
$dirs["$dir/$file"] = "$uri/$file";
continue;
}
$icon_files["$dir/$file"] = "$uri/$file";
}
closedir($dh);
}
}
wp_cache_add( 'icon_files', $icon_files, 'default', 600 );
}

$types = array();
// Icon basename - extension = MIME wildcard.
foreach ( $icon_files as $file => $uri )
$types[ preg_replace('/^([^.]*).*$/', '$1', basename($file)) ] =& $icon_files[$file];

if ( ! empty($mime) ) {
$post_mimes[] = substr($mime, 0, strpos($mime, '/'));
$post_mimes[] = substr($mime, strpos($mime, '/') + 1);
$post_mimes[] = str_replace('/', '_', $mime);
}

$matches = wp_match_mime_types(array_keys($types), $post_mimes);
$matches['default'] = array('default');

foreach ( $matches as $match => $wilds ) {
if ( isset($types[$wilds[0]])) {
$icon = $types[$wilds[0]];
if ( !is_numeric($mime) )
wp_cache_add("mime_type_icon_$mime", $icon);
break;
}
}
}

/**
* Filter the mime type icon.
*
* @since 2.1.0
*
* @param string $icon Path to the mime type icon.
* @param string $mime Mime type.
* @param int $post_id Attachment ID. Will equal 0 if the function passed
* the mime type.
*/
return apply_filters( 'wp_mime_type_icon', $icon, $mime, $post_id );
}