public function isFile($filename)
    {
        $absolutePath = $this->parser->absoluteFilePath($filename);

        return file_exists($absolutePath) && is_file($absolutePath) ? $absolutePath : null;
    }
public function isFile($filename)
    {
        $absolutePath = $this->parser->absoluteFilePath($filename);

        return file_exists($absolutePath) && is_file($absolutePath) ? $absolutePath : null;
    }
public function isFile ( $ filename ) { $ absolutePath = $ this -> parser -> absoluteFilePath ( $ filename ) ; return file_exists ( $ absolutePath ) && is_file ( $ absolutePath ) ? $ absolutePath : null ; }
Is this filename any type of file?

@param  string  $filename
@return boolean
Is this filename any type of file?