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.

* Using the User Agent Class

  * Initializing the Class

  * User Agent Definitions

  * Example

* Class Reference


Using the User Agent Class
==========================


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.)


Class Reference
===============

class CI_User_agent

   is_browser([$key = NULL])

      Parameters:
         * **$key** ("string") – Optional browser name

      Returns:
         TRUE if the user agent is a (specified) browser, FALSE if not

      Return type:
         "bool"

      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.

   is_mobile([$key = NULL])

      Parameters:
         * **$key** ("string") – Optional mobile device name

      Returns:
         TRUE if the user agent is a (specified) mobile device, FALSE
         if not

      Return type:
         "bool"

      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');
         }

   is_robot([$key = NULL])

      Parameters:
         * **$key** ("string") – Optional robot name

      Returns:
         TRUE if the user agent is a (specified) robot, FALSE if not

      Return type:
         "bool"

      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.

   is_referral()

      Returns:
         TRUE if the user agent is a referral, FALSE if not

      Return type:
         "bool"

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

   browser()

      Returns:
         Detected browser or an empty string

      Return type:
         "string"

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

   version()

      Returns:
         Detected browser version or an empty string

      Return type:
         "string"

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

   mobile()

      Returns:
         Detected mobile device brand or an empty string

      Return type:
         "string"

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

   robot()

      Returns:
         Detected robot name or an empty string

      Return type:
         "string"

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

   platform()

      Returns:
         Detected operating system or an empty string

      Return type:
         "string"

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

   referrer()

      Returns:
         Detected referrer or an empty string

      Return type:
         "string"

      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();
         }

   agent_string()

      Returns:
         Full user agent string or an empty string

      Return type:
         "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

   accept_lang([$lang = 'en'])

      Parameters:
         * **$lang** ("string") – Language key

      Returns:
         TRUE if provided language is accepted, FALSE if not

      Return type:
         "bool"

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

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

      Note:

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

   languages()

      Returns:
         An array list of accepted languages

      Return type:
         "array"

      Returns an array of languages supported by the user agent.

   accept_charset([$charset = 'utf-8'])

      Parameters:
         * **$charset** ("string") – Character set

      Returns:
         TRUE if the character set is accepted, FALSE if not

      Return type:
         "bool"

      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 method 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.

   charsets()

      Returns:
         An array list of accepted character sets

      Return type:
         "array"

      Returns an array of character sets accepted by the user agent.

   parse($string)

      Parameters:
         * **$string** ("string") – A custom user-agent string

      Return type:
         "void"

      Parses a custom user-agent string, different from the one
      reported by the current visitor.
