Detect User Agent with PHP

mobileUA.php

<?php

class Mobile_Detect {

	protected $accept;
	protected $userAgent;

	protected $isMobile = false;
	protected $isAndroid = null;
	protected $isBlackberry = null;
	protected $isIphone = null;
	protected $isIpad = null;
	protected $isOpera = null;
	protected $isPalm = null;
	protected $isWindows = null;
	protected $isGeneric = null;

	protected $devices = array(
		"android" => "android",
		"blackberry" => "blackberry",
		"iphone" => "(iphone|ipod)",
		"ipad" => "ipad",
		"opera" => "opera mini",
		"palm" => "(avantgo|blazer|elaine|hiptop|palm|plucker|xiino)",
		"windows" => "windows ce; (iemobile|ppc|smartphone)",
		"generic" => "(kindle|mobile|mmp|midp|o2|pda|pocket|psp|symbian|smartphone|treo|up.browser|up.link|vodafone|wap)"
	);

	public function __construct() {
		$this->userAgent = isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : '';
		$this->accept = isset( $_SERVER['HTTP_ACCEPT'] ) ? $_SERVER['HTTP_ACCEPT'] : '';

		if (isset($_SERVER['HTTP_X_WAP_PROFILE'])|| isset($_SERVER['HTTP_PROFILE'])) {
			$this->isMobile = true;
		} elseif (strpos($this->accept,'text/vnd.wap.wml') > 0 || strpos($this->accept,'application/vnd.wap.xhtml+xml') > 0) {
			$this->isMobile = true;
		} else {
			foreach ($this->devices as $device => $regexp) {
				if ($this->isDevice($device)) {
					$this->isMobile = true;
				}
			}
		}
	}

	public function __call($name, $arguments) {
		$device = strtolower(substr($name, 2));
		if ($name == "is" . ucfirst($device)) {
			return $this->isDevice($device);
		} else {
			trigger_error("Method $name not defined", E_USER_ERROR);
		}
	}

	public function isMobile() {
		return $this->isMobile;
	}

	protected function isDevice($device) {
		$var = "is" . ucfirst($device);
		$return = $this->$var === null ? (bool) preg_match("/" . $this->devices[$device] . "/i", $this->userAgent) : $this->$var;
		if ($device != 'generic' && $return == true) {
			$this->isGeneric = false;
		}
		return $return;
	}
}