user_guide_src/source/libraries/user_agent.rst

################
User Agent Class
################

The User Agent Class provides functions that help identify information
about the browser, mobile device, or robot visiting your site. In
addition you can get referrer information as well as language and
supported character-set information.

Initializing the Class
======================

Like most other classes in CodeIgniter, the User Agent class is
initialized in your controller using the $this->load->library function::

	$this->load->library('user_agent');

Once loaded, the object will be available using: $this->agent

User Agent Definitions
======================

The user agent name definitions are located in a config file located at:
application/config/user_agents.php. You may add items to the various
user agent arrays if needed.

Example
=======

When the User Agent class is initialized it will attempt to determine
whether the user agent browsing your site is a web browser, a mobile
device, or a robot. It will also gather the platform information if it
is available.

::

	$this->load->library('user_agent');

	if ($this->agent->is_browser())
	{
	    $agent = $this->agent->browser().' '.$this->agent->version();
	}
	elseif ($this->agent->is_robot())
	{
	    $agent = $this->agent->robot();
	}
	elseif ($this->agent->is_mobile())
	{
	    $agent = $this->agent->mobile();
	}
	else
	{
	    $agent = 'Unidentified User Agent';
	}

	echo $agent;

	echo $this->agent->platform(); // Platform info (Windows, Linux, Mac, etc.)

******************
Function Reference
******************

$this->agent->is_browser()
===========================

Returns TRUE/FALSE (boolean) if the user agent is a known web browser.

::

	if ($this->agent->is_browser('Safari'))
	{
	    echo 'You are using Safari.';
	}
	elseif ($this->agent->is_browser())
	{
	    echo 'You are using a browser.';
	}
	

.. note:: The string "Safari" in this example is an array key in the
	list of browser definitions. You can find this list in
	application/config/user_agents.php if you want to add new browsers or
	change the stings.

$this->agent->is_mobile()
==========================

Returns TRUE/FALSE (boolean) if the user agent is a known mobile device.

::

	if ($this->agent->is_mobile('iphone'))
	{
	    $this->load->view('iphone/home');
	}
	elseif ($this->agent->is_mobile())
	{
	    $this->load->view('mobile/home');
	}
	else
	{
	    $this->load->view('web/home');
	}
	

$this->agent->is_robot()
=========================

Returns TRUE/FALSE (boolean) if the user agent is a known robot.

.. note:: The user agent library only contains the most common robot
	definitions. It is not a complete list of bots. There are hundreds of
	them so searching for each one would not be very efficient. If you find
	that some bots that commonly visit your site are missing from the list
	you can add them to your application/config/user_agents.php file.

$this->agent->is_referral()
============================

Returns TRUE/FALSE (boolean) if the user agent was referred from another
site.

$this->agent->browser()
=======================

Returns a string containing the name of the web browser viewing your
site.

$this->agent->version()
=======================

Returns a string containing the version number of the web browser
viewing your site.

$this->agent->mobile()
======================

Returns a string containing the name of the mobile device viewing your
site.

$this->agent->robot()
=====================

Returns a string containing the name of the robot viewing your site.

$this->agent->platform()
========================

Returns a string containing the platform viewing your site (Linux,
Windows, OS X, etc.).

$this->agent->referrer()
========================

The referrer, if the user agent was referred from another site.
Typically you'll test for this as follows::

	if ($this->agent->is_referral())
	{
	    echo $this->agent->referrer();
	}

$this->agent->agent_string()
=============================

Returns a string containing the full user agent string. Typically it
will be something like this::

	Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.4) Gecko/20060613 Camino/1.0.2

$this->agent->accept_lang()
============================

Lets you determine if the user agent accepts a particular language.
Example::

	if ($this->agent->accept_lang('en'))
	{
	    echo 'You accept English!';
	}

.. note:: This function is not typically very reliable since some
	browsers do not provide language info, and even among those that do, it
	is not always accurate.

$this->agent->accept_charset()
===============================

Lets you determine if the user agent accepts a particular character set.
Example::

	if ($this->agent->accept_charset('utf-8'))
	{
	    echo 'You browser supports UTF-8!';
	}

.. note:: This function is not typically very reliable since some
	browsers do not provide character-set info, and even among those that
	do, it is not always accurate.