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<?php// This file is part of Moodle - http://moodle.org///// Moodle is free software: you can redistribute it and/or modify// it under the terms of the GNU General Public License as published by// the Free Software Foundation, either version 3 of the License, or// (at your option) any later version.//// Moodle 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 General Public License// along with Moodle. If not, see <http://www.gnu.org/licenses/>./*** Environment class to aid with the detection and establishment of the working environment.** @package core* @copyright 2013 Sam Hemelryk* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*//*** The user agent class.** It's important to note that we do not like browser sniffing and its use in core code is highly discouraged.* No new uses of this API will be integrated unless there is absolutely no alternative.** This API supports the few browser checks we do have in core, all of which one day will hopefully be removed.* The API will remain to support any third party use out there, however at some point like all code it will be deprecated.** Use sparingly and only with good cause!** @package core* @copyright 2013 Sam Hemelryk* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*/class core_useragent {/*** The default for devices, think of as a computer.*/const DEVICETYPE_DEFAULT = 'default';/*** Legacy devices, or at least legacy browsers. These are older devices/browsers* that don't support standards.*/const DEVICETYPE_LEGACY = 'legacy';/*** Mobile devices like your cell phone or hand held gaming device.*/const DEVICETYPE_MOBILE = 'mobile';/*** Tables, larger than hand held, but still easily portable and smaller than a laptop.*/const DEVICETYPE_TABLET = 'tablet';/*** An instance of this class.* @var core_useragent*/protected static $instance = null;/*** The device types we track.* @var array*/public static $devicetypes = array(self::DEVICETYPE_DEFAULT,self::DEVICETYPE_LEGACY,self::DEVICETYPE_MOBILE,self::DEVICETYPE_TABLET,);/*** The current requests user agent string if there was one.* @var string|bool|null Null until initialised, false if none available, or string when available.*/protected $useragent = null;/*** The users device type, one of self::DEVICETYPE_*.* @var string null until initialised*/protected $devicetype = null;/*** True if the user agent supports the display of svg images. False if not.* @var bool|null Null until initialised, then true or false.*/protected $supportssvg = null;/*** Get an instance of the user agent object.** @param bool $reload If set to true the user agent will be reset and all ascertations remade.* @param string $forceuseragent The string to force as the user agent, don't use unless absolutely unavoidable.* @return core_useragent*/public static function instance($reload = false, $forceuseragent = null) {if (!self::$instance || $reload) {self::$instance = new core_useragent($forceuseragent);}return self::$instance;}/*** Constructs a new user agent object. Publically you must use the instance method above.** @param string|null $forceuseragent Optional a user agent to force.*/protected function __construct($forceuseragent = null) {if ($forceuseragent !== null) {$this->useragent = $forceuseragent;} else if (!empty($_SERVER['HTTP_USER_AGENT'])) {$this->useragent = $_SERVER['HTTP_USER_AGENT'];} else {$this->useragent = false;$this->devicetype = self::DEVICETYPE_DEFAULT;}}/*** Get the MoodleBot UserAgent for this site.** @return string UserAgent*/public static function get_moodlebot_useragent() {global $CFG;$version = moodle_major_version(); // Only major version for security.return "MoodleBot/$version (+{$CFG->wwwroot})";}/*** Returns the user agent string.* @return bool|string The user agent string or false if one isn't available.*/public static function get_user_agent_string() {$instance = self::instance();return $instance->useragent;}/*** Returns the device type we believe is being used.* @return string*/public static function get_device_type() {$instance = self::instance();if ($instance->devicetype === null) {return $instance->guess_device_type();}return $instance->devicetype;}/*** Guesses the device type the user agent is running on.** @return string*/protected function guess_device_type() {if ($this->is_useragent_mobile()) {$this->devicetype = self::DEVICETYPE_MOBILE;} else if ($this->is_useragent_tablet()) {$this->devicetype = self::DEVICETYPE_TABLET;} else if (self::check_ie_version('0') && !self::check_ie_version('7.0')) {// IE 6 and before are considered legacy.$this->devicetype = self::DEVICETYPE_LEGACY;} else {$this->devicetype = self::DEVICETYPE_DEFAULT;}return $this->devicetype;}/*** Returns true if the user appears to be on a mobile device.* @return bool*/protected function is_useragent_mobile() {// Mobile detection PHP direct copy from open source detectmobilebrowser.com.$phonesregex = '/android .+ mobile|avantgo|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|symbian|treo|up\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino/i';$modelsregex = '/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|e\-|e\/|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(di|rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|xda(\-|2|g)|yas\-|your|zeto|zte\-/i';return (preg_match($phonesregex, $this->useragent) || preg_match($modelsregex, substr($this->useragent, 0, 4)));}/*** Returns true if the user appears to be on a tablet.** @return int*/protected function is_useragent_tablet() {$tabletregex = '/Tablet browser|android|iPad|iProd|GT-P1000|GT-I9000|SHW-M180S|SGH-T849|SCH-I800|Build\/ERE27|sholest/i';return (preg_match($tabletregex, $this->useragent));}/*** Whether the user agent relates to a web crawler.* This includes all types of web crawler.* @return bool*/protected function is_useragent_web_crawler() {$regex = '/MoodleBot|Googlebot|google\.com|Yahoo! Slurp|\[ZSEBOT\]|msnbot|bingbot|BingPreview|Yandex|AltaVista'.'|Baiduspider|Teoma/i';return (preg_match($regex, $this->useragent));}/*** Gets a list of known device types.** @deprecated Moodle 4.3 MDL-78468 - No longer used. Please use core_useragent::devicetypes instead.* @todo Final deprecation on Moodle 4.7 MDL-79052* @param bool $includecustomtypes If set to true we'll include types that have been added by the admin.* @return array*/public static function get_device_type_list($includecustomtypes = true) {debugging(__FUNCTION__ . '() is deprecated.' .'All functions associated with devicedetectregex theme setting are being removed.Please use core_useragent::devicetypes instead',DEBUG_DEVELOPER);$types = self::$devicetypes;if ($includecustomtypes) {$instance = self::instance();$types = array_merge($types, array_keys($instance->devicetypecustoms));}return $types;}/*** Returns the theme to use for the given device type.** This used to be get_selected_theme_for_device_type.* @param null|string $devicetype The device type to find out for. Defaults to the device the user is using,* @deprecated since 4.3.* @return bool*/public static function get_device_type_theme($devicetype = null) {debugging(__FUNCTION__ . '() is deprecated.' .'All functions associated with device specific themes are being removed.',DEBUG_DEVELOPER);global $CFG;if ($devicetype === null) {$devicetype = self::get_device_type();}$themevarname = self::get_device_type_cfg_var_name($devicetype);if (empty($CFG->$themevarname)) {return false;}return $CFG->$themevarname;}/*** Returns the CFG var used to find the theme to use for the given device.** Used to be get_device_cfg_var_name.** @param null|string $devicetype The device type to find out for. Defaults to the device the user is using,* @deprecated since 4.3.* @return string*/public static function get_device_type_cfg_var_name($devicetype = null) {debugging(__FUNCTION__ . '() is deprecated.' .'All functions associated with device specific themes are being removed.',DEBUG_DEVELOPER);if ($devicetype == self::DEVICETYPE_DEFAULT || empty($devicetype)) {return 'theme';}return 'theme' . $devicetype;}/*** Gets the device type the user is currently using.* @return string*/public static function get_user_device_type() {$device = self::get_device_type();$switched = get_user_preferences('switchdevice'.$device, false);if ($switched != false) {return $switched;}return $device;}/*** Switches the device type we think the user is using to what ever was given.* @param string $newdevice* @return bool* @throws coding_exception*/public static function set_user_device_type($newdevice) {$devicetype = self::get_device_type();if ($newdevice == $devicetype) {unset_user_preference('switchdevice'.$devicetype);return true;} else {$devicetypes = self::$devicetypes;if (in_array($newdevice, $devicetypes)) {set_user_preference('switchdevice'.$devicetype, $newdevice);return true;}}throw new coding_exception('Invalid device type provided to set_user_device_type');}/*** Returns true if the user agent matches the given brand and the version is equal to or greater than that specified.** @param string $brand The branch to check for.* @param scalar $version The version if we need to find out if it is equal to or greater than that specified.* @return bool*/public static function check_browser_version($brand, $version = null) {switch ($brand) {case 'MSIE':// Internet Explorer.return self::check_ie_version($version);case 'Edge':// Microsoft Edge.return self::check_edge_version($version);case 'Firefox':// Mozilla Firefox browsers.return self::check_firefox_version($version);case 'Chrome':return self::check_chrome_version($version);case 'Opera':// Opera.return self::check_opera_version($version);case 'Safari':// Desktop version of Apple Safari browser - no mobile or touch devices.return self::check_safari_version($version);case 'Safari iOS':// Safari on iPhone, iPad and iPod touch.return self::check_safari_ios_version($version);case 'WebKit':// WebKit based browser - everything derived from it (Safari, Chrome, iOS, Android and other mobiles).return self::check_webkit_version($version);case 'Gecko':// Gecko based browsers.return self::check_gecko_version($version);case 'WebKit Android':// WebKit browser on Android.return self::check_webkit_android_version($version);case 'Camino':// OSX browser using Gecke engine.return self::check_camino_version($version);}// Who knows?! doesn't pass anyway.return false;}/*** Checks the user agent is camino based and that the version is equal to or greater than that specified.** Camino browser is at the end of its life, its no longer being developed or supported, just don't worry about it.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/protected static function check_camino_version($version = null) {// OSX browser using Gecko engine.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Camino') === false) {return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/Camino\/([0-9\.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Firefox (of any version).** @return bool true if firefox*/public static function is_firefox() {return self::check_firefox_version();}/*** Checks the user agent is Firefox based and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_firefox_version($version = null) {// Mozilla Firefox browsers.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Firefox') === false && strpos($useragent, 'Iceweasel') === false) {return false;}if (empty($version)) {return true; // No version specified..}if (preg_match("/(Iceweasel|Firefox)\/([0-9\.]+)/i", $useragent, $match)) {if (version_compare($match[2], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Gecko based (of any version).** @return bool true if Gecko based.*/public static function is_gecko() {return self::check_gecko_version();}/*** Checks the user agent is Gecko based and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_gecko_version($version = null) {// Gecko based browsers.// Do not look for dates any more, we expect real Firefox version here.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (empty($version)) {$version = 1;} else if ($version > 20000000) {// This is just a guess, it is not supposed to be 100% accurate!if (preg_match('/^201/', $version)) {$version = 3.6;} else if (preg_match('/^200[7-9]/', $version)) {$version = 3;} else if (preg_match('/^2006/', $version)) {$version = 2;} else {$version = 1.5;}}if (preg_match("/(Iceweasel|Firefox)\/([0-9\.]+)/i", $useragent, $match)) {// Use real Firefox version if specified in user agent string.if (version_compare($match[2], $version) >= 0) {return true;}} else if (preg_match("/Gecko\/([0-9\.]+)/i", $useragent, $match)) {// Gecko might contain date or Firefox revision, let's just guess the Firefox version from the date.$browserver = $match[1];if ($browserver > 20000000) {// This is just a guess, it is not supposed to be 100% accurate!if (preg_match('/^201/', $browserver)) {$browserver = 3.6;} else if (preg_match('/^200[7-9]/', $browserver)) {$browserver = 3;} else if (preg_match('/^2006/', $version)) {$browserver = 2;} else {$browserver = 1.5;}}if (version_compare($browserver, $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Edge (of any version).** @return bool true if Edge*/public static function is_edge() {return self::check_edge_version();}/*** Check the User Agent for the version of Edge.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_edge_version($version = null) {$useragent = self::get_user_agent_string();if ($useragent === false) {// No User Agent found.return false;}if (strpos($useragent, 'Edge/') === false) {// Edge was not found in the UA - this is not Edge.return false;}if (empty($version)) {// No version to check.return true;}// Find the version.// Edge versions are always in the format:// Edge/<version>.<OS build number>preg_match('%Edge/([\d]+)\.(.*)$%', $useragent, $matches);// Just to be safe, round the version being tested.// Edge only uses integer versions - the second component is the OS build number.$version = round($version);// Check whether the version specified is >= the version found.return version_compare($matches[1], $version, '>=');}/*** Checks the user agent is IE (of any version).** @return bool true if internet exporeer*/public static function is_ie() {return self::check_ie_version();}/*** Checks the user agent is IE and returns its main properties:* - browser version;* - whether running in compatibility view.** @return bool|array False if not IE, otherwise an associative array of properties.*/public static function check_ie_properties() {// Internet Explorer.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Opera') !== false) {// Reject Opera.return false;}// See: http://www.useragentstring.com/pages/Internet%20Explorer/.if (preg_match("/MSIE ([0-9\.]+)/", $useragent, $match)) {$browser = $match[1];// See: http://msdn.microsoft.com/en-us/library/ie/bg182625%28v=vs.85%29.aspx for IE11+ useragent details.} else if (preg_match("/Trident\/[0-9\.]+/", $useragent) && preg_match("/rv:([0-9\.]+)/", $useragent, $match)) {$browser = $match[1];} else {return false;}$compatview = false;// IE8 and later versions may pretend to be IE7 for intranet sites, use Trident version instead,// the Trident should always describe the capabilities of IE in any emulation mode.if ($browser === '7.0' and preg_match("/Trident\/([0-9\.]+)/", $useragent, $match)) {$compatview = true;$browser = $match[1] + 4; // NOTE: Hopefully this will work also for future IE versions.}$browser = round($browser, 1);return array('version' => $browser,'compatview' => $compatview);}/*** Checks the user agent is IE and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_ie_version($version = null) {// Internet Explorer.$properties = self::check_ie_properties();if (!is_array($properties)) {return false;}// In case of IE we have to deal with BC of the version parameter.if (is_null($version)) {$version = 5.5; // Anything older is not considered a browser at all!}// IE uses simple versions, let's cast it to float to simplify the logic here.$version = round($version, 1);return ($properties['version'] >= $version);}/*** Checks the user agent is IE and that IE is running under Compatibility View setting.** @return bool true if internet explorer runs in Compatibility View mode.*/public static function check_ie_compatibility_view() {// IE User Agent string when in Compatibility View:// - IE 8: "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; ...)".// - IE 9: "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; ...)".// - IE 10: "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/6.0; ...)".// - IE 11: "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.3; Trident/7.0; ...)".// Refs:// - http://blogs.msdn.com/b/ie/archive/2009/01/09/the-internet-explorer-8-user-agent-string-updated-edition.aspx.// - http://blogs.msdn.com/b/ie/archive/2010/03/23/introducing-ie9-s-user-agent-string.aspx.// - http://blogs.msdn.com/b/ie/archive/2011/04/15/the-ie10-user-agent-string.aspx.// - http://msdn.microsoft.com/en-us/library/ie/hh869301%28v=vs.85%29.aspx.$properties = self::check_ie_properties();if (!is_array($properties)) {return false;}return $properties['compatview'];}/*** Checks the user agent is Opera (of any version).** @return bool true if opera*/public static function is_opera() {return self::check_opera_version();}/*** Checks the user agent is Opera and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_opera_version($version = null) {// Opera.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Opera') === false) {return false;}if (empty($version)) {return true; // No version specified.}// Recent Opera useragents have Version/ with the actual version, e.g.:// Opera/9.80 (Windows NT 6.1; WOW64; U; en) Presto/2.10.289 Version/12.01// That's Opera 12.01, not 9.8.if (preg_match("/Version\/([0-9\.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}} else if (preg_match("/Opera\/([0-9\.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is webkit based** @return bool true if webkit*/public static function is_webkit() {return self::check_webkit_version();}/*** Checks the user agent is Webkit based and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_webkit_version($version = null) {// WebKit based browser - everything derived from it (Safari, Chrome, iOS, Android and other mobiles).$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'AppleWebKit') === false) {return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/AppleWebKit\/([0-9.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Safari** @return bool true if safari*/public static function is_safari() {return self::check_safari_version();}/*** Checks the user agent is Safari based and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_safari_version($version = null) {// Desktop version of Apple Safari browser - no mobile or touch devices.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'AppleWebKit') === false) {return false;}// Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SymbianOS and any other mobile devices.if (strpos($useragent, 'OmniWeb')) {// Reject OmniWeb.return false;}if (strpos($useragent, 'Shiira')) {// Reject Shiira.return false;}if (strpos($useragent, 'SymbianOS')) {// Reject SymbianOS.return false;}if (strpos($useragent, 'Android')) {// Reject Androids too.return false;}if (strpos($useragent, 'iPhone') or strpos($useragent, 'iPad') or strpos($useragent, 'iPod')) {// No Apple mobile devices here - editor does not work, course ajax is not touch compatible, etc.return false;}if (strpos($useragent, 'Chrome')) {// Reject chrome browsers - it needs to be tested explicitly.// This will also reject Edge, which pretends to be both Chrome, and Safari.return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/AppleWebKit\/([0-9.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Chrome** @return bool true if chrome*/public static function is_chrome() {return self::check_chrome_version();}/*** Checks the user agent is Chrome based and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_chrome_version($version = null) {// Chrome.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Chrome') === false) {return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/Chrome\/(.*)[ ]+/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is webkit android based.** @return bool true if webkit based and on Android*/public static function is_webkit_android() {return self::check_webkit_android_version();}/*** Checks the user agent is Webkit based and on Android and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_webkit_android_version($version = null) {// WebKit browser on Android.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'Android') === false) {return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/AppleWebKit\/([0-9]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks the user agent is Safari on iOS** @return bool true if Safari on iOS*/public static function is_safari_ios() {return self::check_safari_ios_version();}/*** Checks the user agent is Safari on iOS and that the version is equal to or greater than that specified.** @param string|int $version A version to check for, returns true if its equal to or greater than that specified.* @return bool*/public static function check_safari_ios_version($version = null) {// Safari on iPhone, iPad and iPod touch.$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'AppleWebKit') === false or strpos($useragent, 'Safari') === false) {return false;}if (!strpos($useragent, 'iPhone') and !strpos($useragent, 'iPad') and !strpos($useragent, 'iPod')) {return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/AppleWebKit\/([0-9]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Checks if the user agent is MS Word.* Not perfect, as older versions of Word use standard IE6/7 user agents without any identifying traits.** @return bool true if user agent could be identified as MS Word.*/public static function is_msword() {$useragent = self::get_user_agent_string();if (!preg_match('/(\bWord\b|ms-office|MSOffice|Microsoft Office)/i', $useragent)) {return false;} else if (strpos($useragent, 'Outlook') !== false) {return false;} else if (strpos($useragent, 'Meridio') !== false) {return false;}// It's Office, not Outlook and not Meridio - so it's probably Word, but we can't really be sure in most cases.return true;}/*** Check if the user agent matches a given brand.** Known brand: 'Windows','Linux','Macintosh','SGI','SunOS','HP-UX'** @param string $brand* @return bool*/public static function check_browser_operating_system($brand) {$useragent = self::get_user_agent_string();return ($useragent !== false && preg_match("/$brand/i", $useragent));}/*** Gets an array of CSS classes to represent the user agent.* @return array*/public static function get_browser_version_classes() {$classes = array();if (self::is_edge()) {$classes[] = 'edge';} else if (self::is_ie()) {$classes[] = 'ie';for ($i = 12; $i >= 6; $i--) {if (self::check_ie_version($i)) {$classes[] = 'ie'.$i;break;}}} else if (self::is_firefox() || self::is_gecko() || self::check_camino_version()) {$classes[] = 'gecko';if (preg_match('/rv\:([1-2])\.([0-9])/', self::get_user_agent_string(), $matches)) {$classes[] = "gecko{$matches[1]}{$matches[2]}";}} else if (self::is_chrome()) {$classes[] = 'chrome';if (self::is_webkit_android()) {$classes[] = 'android';}} else if (self::is_webkit()) {if (self::is_safari()) {$classes[] = 'safari';}if (self::is_safari_ios()) {$classes[] = 'ios';} else if (self::is_webkit_android()) {$classes[] = 'android'; // Old pre-Chrome android browsers.}} else if (self::is_opera()) {$classes[] = 'opera';}return $classes;}/*** Returns true if the user agent supports the display of SVG images.** @return bool*/public static function supports_svg() {$instance = self::instance();if ($instance->supportssvg === null) {if (preg_match('#Android +[0-2]\.#', $instance->useragent)) {// Android < 3 doesn't support SVG.$instance->supportssvg = false;} else {// With widespread SVG support in modern browsers, default to returning true (even when useragent is false).$instance->supportssvg = true;}}return $instance->supportssvg;}/*** Returns true if the user agent supports the MIME media type for JSON text, as defined in RFC 4627.** @return bool*/public static function supports_json_contenttype() {// Modern browsers other than IE correctly supports 'application/json' media type.if (!self::check_ie_version('0')) {return true;}// IE8+ supports 'application/json' media type, when NOT in Compatibility View mode.// Refs:// - http://blogs.msdn.com/b/ie/archive/2008/09/10/native-json-in-ie8.aspx;// - MDL-39810: issues when using 'text/plain' in Compatibility View for the body of an HTTP POST response.if (self::check_ie_version(8) && !self::check_ie_compatibility_view()) {return true;}// This browser does not support json.return false;}/*** Returns true if the client appears to be some kind of web crawler.* This may include other types of crawler.** @return bool*/public static function is_web_crawler() {$instance = self::instance();return (bool) $instance->is_useragent_web_crawler();}/*** Returns true if the client appears to be a device using iOS (iPhone, iPad, iPod).** @param scalar $version The version if we need to find out if it is equal to or greater than that specified.* @return bool true if the client is using iOS* @since Moodle 3.2*/public static function is_ios($version = null) {$useragent = self::get_user_agent_string();if ($useragent === false) {return false;}if (strpos($useragent, 'AppleWebKit') === false) {return false;}if (strpos($useragent, 'Windows')) {// Reject Windows Safari.return false;}if (strpos($useragent, 'Macintosh')) {// Reject MacOS Safari.return false;}// Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SymbianOS and any other mobile devices.if (strpos($useragent, 'OmniWeb')) {// Reject OmniWeb.return false;}if (strpos($useragent, 'Shiira')) {// Reject Shiira.return false;}if (strpos($useragent, 'SymbianOS')) {// Reject SymbianOS.return false;}if (strpos($useragent, 'Android')) {// Reject Androids too.return false;}if (strpos($useragent, 'Chrome')) {// Reject chrome browsers - it needs to be tested explicitly.// This will also reject Edge, which pretends to be both Chrome, and Safari.return false;}if (empty($version)) {return true; // No version specified.}if (preg_match("/AppleWebKit\/([0-9.]+)/i", $useragent, $match)) {if (version_compare($match[1], $version) >= 0) {return true;}}return false;}/*** Returns true if the client appears to be the Moodle app (or an app based on the Moodle app code).** @return bool true if the client is the Moodle app* @since Moodle 3.7*/public static function is_moodle_app() {$useragent = self::get_user_agent_string();// Make it case insensitive, things can change in the app or desktop app depending on the platform frameworks.if (stripos($useragent, 'MoodleMobile') !== false) {return true;}return false;}/*** Checks if current browser supports files with give extension as <video> or <audio> source** Note, the check here is not 100% accurate!** First, we do not know which codec is used in .mp4 or .webm files. Not all browsers support* all codecs.** Also we assume that users of Firefox/Chrome/Safari do not use the ancient versions of browsers.** We check the exact version for IE/Edge though. We know that there are still users of very old* versions that are afraid to upgrade or have slow IT department.** Resources:* https://developer.mozilla.org/en-US/docs/Web/HTML/Supported_media_formats* https://en.wikipedia.org/wiki/HTML5_video* https://en.wikipedia.org/wiki/HTML5_Audio** @param string $extension extension without leading .* @return bool*/public static function supports_html5($extension) {$extension = strtolower($extension);$supportedvideo = array('m4v', 'webm', 'ogv', 'mp4', 'mov', 'fmp4');$supportedaudio = array('ogg', 'oga', 'aac', 'm4a', 'mp3', 'wav', 'flac');// Basic extension support.if (!in_array($extension, $supportedvideo) && !in_array($extension, $supportedaudio)) {return false;}// MS IE support - version 9.0 or later.if (self::is_ie() && !self::check_ie_version('9.0')) {return false;}// MS Edge support - version 12.0 for desktop and 13.0 for mobile.if (self::is_edge()) {if (!self::check_edge_version('12.0')) {return false;}if (self::instance()->is_useragent_mobile() && !self::check_edge_version('13.0')) {return false;}}// Different exceptions.// Webm is not supported in IE, Edge and in Safari.if ($extension === 'webm' &&(self::is_ie() || self::is_edge() || self::is_safari() || self::is_safari_ios())) {return false;}// Ogg is not supported in IE, Edge and Safari.$isogg = in_array($extension, ['ogg', 'oga', 'ogv']);if ($isogg && (self::is_ie() || self::is_edge() || self::is_safari() || self::is_safari_ios())) {return false;}// FLAC is not supported in IE and Edge (below 16.0).if ($extension === 'flac' &&(self::is_ie() || (self::is_edge() && !self::check_edge_version('16.0')))) {return false;}// Wave is not supported in IE.if ($extension === 'wav' && self::is_ie()) {return false;}// Aac is not supported in IE below 11.0.if ($extension === 'aac' && (self::is_ie() && !self::check_ie_version('11.0'))) {return false;}// Mpeg is not supported in IE below 10.0.$ismpeg = in_array($extension, ['m4a', 'mp3', 'm4v', 'mp4', 'fmp4']);if ($ismpeg && (self::is_ie() && !self::check_ie_version('10.0'))) {return false;}// Mov is not supported in IE.if ($extension === 'mov' && self::is_ie()) {return false;}return true;}/*** Checks if current browser supports the HLS and MPEG-DASH media* streaming formats. Most browsers get this from Media Source Extensions.* Safari on iOS, doesn't support MPEG-DASH at all.** Note, the check here is not 100% accurate!** Also we assume that users of Firefox/Chrome/Safari do not use the ancient versions of browsers.* We check the exact version for IE/Edge though. We know that there are still users of very old* versions that are afraid to upgrade or have slow IT department.** Resources:* https://developer.mozilla.org/en-US/docs/Web/API/Media_Source_Extensions_API* https://caniuse.com/#search=mpeg-dash* https://caniuse.com/#search=hls** @param string $extension* @return bool*/public static function supports_media_source_extensions(string $extension): bool {// Not supported in IE below 11.0.if (self::is_ie() && !self::check_ie_version('11.0')) {return false;}if ($extension == '.mpd') {// Not supported in Safari on iOS.if (self::is_safari_ios()) {return false;}}return true;}}