Omni Impact Mobile Browser Detection and Support

oi_mobilesupport.php

<?php

/*

Omni Impact Mobile Support Helper Script

Published under the GNU/LGPL v3

Copyright 2010-2011 Daniel Marcus / OmniImpact

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.

This script provides mobile website support for over 20 detectable mobile browsers.
This script provides convenience functions for make a mobile-ready website.

== EXAMPLE USE ==

<?php
session_start();
?>
<!-- SOME HTML -->
<?php
//add a mobile stylesheet
$MS = new oi_mobilesupport;
$MS->addMobileStyle();
?>
<!-- SOME MORE HTML -->
Mobile Mode is <?php $MS->mobileEcho('ON', 'OFF'); echo(' turn it '); $MS->mobileToggle('ON', 'OFF'); ?>.

*/

class oi_mobilesupport{

	private $isMobile = false;
	private $useMobile = false;
	private $requestString = null;

	function __construct(){
		//The constructor will check two things;
		//Is the user on a mobile browser?
		//Has the user selected an override?
		//
		//There are three modes.
		//	1 : No override selected
		//	2 : Mobile Forced
		//	3 : Desktop Forced
		
		//if we aren't initialized, set the $_SESSION['mobileoverride']
		//if(!isset($_SESSION['mobileoverride'])) $_SESSION['mobileoverride'] = '1';
		
		//allow 'clear', 'auto', 'mobile', 'phone', 'desktop', 'full' to be used
		if($_REQUEST['mobileoverride'] == 'auto' || $_REQUEST['mobileoverride'] == 'clear') $_REQUEST['mobileoverride'] = '1';
		if($_REQUEST['mobileoverride'] == 'mobile' || $_REQUEST['phone'] == 'phone') $_REQUEST['mobileoverride'] = '2';
		if($_REQUEST['mobileoverride'] == 'desktop' || $_REQUEST['mobileoverride'] == 'full') $_REQUEST['mobileoverride'] = '3';
		
		//check to see if the user is trying to SET an override
		//it will be safe to set the session variable directly, because it is ONLY triggered if we already know
		//that it is one of three safe values
		if($_REQUEST['mobileoverride'] == '1' || $_REQUEST['mobileoverride'] == '2' || $_REQUEST['mobileoverride'] == '3'){
			$_SESSION['mobileoverride'] = $_REQUEST['mobileoverride'];
		}
		
		//is the user on a mobile device?
		if(	stripos($_SERVER['HTTP_USER_AGENT'], "phone") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "droid") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "palm") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "avantgo") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "docomo") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "windows ce") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "minimo") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "netfront") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "wm5 pie") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "xiino") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "opera mobi") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "mobile") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "blackberry") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "opera mini") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "polaris") ||
			strpos($_SERVER['HTTP_USER_AGENT'], "LGE") ||
			strpos($_SERVER['HTTP_USER_AGENT'], "MIDP") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "nintendo") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "nokia") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "kindle") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "samsung") ||
			stripos($_SERVER['HTTP_USER_AGENT'], "tear")
			){
			$this->isMobile = true;
		}
		
		//should we be using a mobile mode?
		if(
			($_SESSION['mobileoverride'] == '2' || $this->isMobile == true) && $_SESSION['mobileoverride'] != '3'
		){
			$this->useMobile = true;
		}else{
			$this->useMobile = false;
		}
		
		//finally, we will build the request string for the current page,
		//but we will strip it of any "mobileoverride" parameter
		//we will need this later to generate a nice switch
		$requestArray = null;
		foreach($_GET as $GETkey => $GETvalue){
			if($GETkey != 'mobileoverride'){
				$requestArray[]= htmlentities($GETkey).'='.htmlentities($GETvalue);
			}
		}
		
		if(is_array($requestArray))$this->requestString = implode('&amp;', $requestArray);
		
	}
	
	//now, a few little convenience functions
	function askMobile(){
		if($this->isMobile) echo('<!-- Mobile Device Detected -->');
	}
	
	function setScale(){
		if($this->useMobile) echo('
		<meta name = "viewport" content = "initial-scale = 1.0, maximum-scale = 1.0">
		<meta name = "viewport" content = "width = device-width">
		');
	}
	
	function isMobile(){
		return $this->isMobile;
	}
	
	function useMobile(){
		return $this->useMobile;
	}
	
	//now for some fun! we know whether the user is on a mobile device
	//and we know if they have forceda mode, so we want to make this convenient
	//we'll use some polymorphic functions to include the stylesheets we want
	//and to generate a toggle to switch modes
	
	function mobileEcho($ifMobile = null, $ifNotMobile = null){
		//echo if applicable
		if($this->useMobile && $ifMobile != null) echo($ifMobile);
		if(!$this->useMobile && $ifNotMobile != null) echo($ifNotMobile);
	}
	
	function addMobileStyle($styleSheetName = null, $lookIn = ''){
	
		//if we're not mobile mode, return false
		if(!$this->useMobile) return false;
	
		//if no $styleSheetName is supplied, try to find it automagically
		//we then populate our own $styleSheetName
		
		//just in case, if $lookIn has a trailing '/' let's remove it
		if($lookIn != '' && substr($lookIn, -1) == '/') $lookIn = substr($lookIn, 0, -1);
		
		if($styleSheetName == null){
			//we will assume (hopefully without making an ass out of you or me...)
			//that mobile stylesheets contain at least one of the phrases
			//'mobile','phone','portable','small', or 'compact' and end with '.css'
			//also, kick out 'old_', '_old', '*~' or '.bak' files
			
			if($lookIn == ''){
				$possibleStyleSheets = scandir('.');
			}else{
				$possibleStyleSheets = scandir($lookIn);
				$lookIn = $lookIn.'/';
			}
						
			foreach($possibleStyleSheets as $possibleStyleSheet){
				if(
					(
						stripos($possibleStyleSheet, 'mobile') !== false ||
						stripos($possibleStyleSheet, 'phone') !== false ||
						stripos($possibleStyleSheet, 'portable') !== false ||
						stripos($possibleStyleSheet, 'small') !== false ||
						stripos($possibleStyleSheet, 'compact') !== false
					) &&
					strtoupper(substr($possibleStyleSheet, -3)) == 'CSS' &&
					!stripos($possibleStyleSheet, '_old') &&
					!stripos($possibleStyleSheet, 'old_') &&
					!stripos($possibleStyleSheet, '.bak') &&
					substr($possibleStyleSheet, -1) != '~'
				){
					$styleSheetName[] = $lookIn.$possibleStyleSheet;
				}
			}
		}
		
		//we can ignore $lookIn now and just include the style sheet(s)
		//if $styleSheetName is an array, we must loop it
		if(is_array($styleSheetName)){
			foreach($styleSheetName as $styleSheet){
				echo('<link rel="stylesheet" href="'.$styleSheet.'" type="text/css"/>');
			}
		}else{
			echo('<link rel="stylesheet" href="'.$styleSheetName.'" type="text/css"/>');
		}
	}
	
	function mobileToggle($toMobile = 'Mobile Mode', $toDesktop = 'Desktop Mode'){
		//This will present a TOGGLE between mobile and desktop modes
		//we can use the isMobile and useMobile variables to help
		//we will default to automatic detection when possible
		
		//if we are in a desktop browser...
		if(!$this->isMobile){
			//...and we are not currently mobile
			if(!$this->useMobile){
				$text = $toMobile;
				$target = 'mobile';
			}else{
				//...and we want to go back to desktop mode
				$text = $toDesktop;
				$target = 'auto';
			}
		}else{
			//we are in a mobile browser...
			//...and we want to use Desktop mode
			if($this->useMobile){
				$text = $toDesktop;
				$target = 'desktop';
			}else{
				//...and we want to go back to mobile mode
				$text = $toMobile;
				$target = 'auto';
			}
		}
		
		if($this->requestString != '') $connector = '&amp;';
		echo('<a href="?'.$this->requestString.$connector.'mobileoverride='.$target.'">'.$text.'</a>');
		
	}

}

Added support for Amazon Kindle series mobile browsers. As of the Kindle 3, it's a pretty full-featured browser, but because it is an e-ink, non-touch screen, it will make the most sense to deliver the mobile optimized content. Additionally, the e-ink screen doesn't handle movement (flash) and the processor is slow, making the Kindle further like a mobile device. I believe that it should also detect Windows Phone 7 correctly (due to the presence of "phone" in the user agent string) but I can make no guarantees of how well the website will display. My own website was displayed horribly on Mobile IE 6.5, but worked fine in Opera on the same phone. If someone has experience with Windows Phone 7, try out the script and let me know the results.

Fixed the licensing, it was supposed to be under LGPL, but the change had not been reflected on the Gist.