yii\helpers\BaseFileHelper::getMimeTypeByExtension PHP Method

getMimeTypeByExtension() public static method

This method will use a local map between extension names and MIME types.
public static getMimeTypeByExtension ( string $file, string $magicFile = null ) : string
$file string the file name.
$magicFile string the path (or alias) of the file that contains all available MIME type information. If this is not set, the file specified by [[mimeMagicFile]] will be used.
return string the MIME type. Null is returned if the MIME type cannot be determined.
    public static function getMimeTypeByExtension($file, $magicFile = null)
    {
        $mimeTypes = static::loadMimeTypes($magicFile);
        if (($ext = pathinfo($file, PATHINFO_EXTENSION)) !== '') {
            $ext = strtolower($ext);
            if (isset($mimeTypes[$ext])) {
                return $mimeTypes[$ext];
            }
        }
        return null;
    }