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<?php |
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/** |
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* A class with HTTP-related helpers. |
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* Like Debug, this is more a bundle of methods than a class ;-) |
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* |
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* @package framework |
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* @subpackage misc |
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*/ |
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class HTTP { |
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/** |
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* @var int $cache_age |
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*/ |
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protected static $cache_age = 0; |
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/** |
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* @var timestamp $modification_date |
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*/ |
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protected static $modification_date = null; |
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/** |
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* @var string $etag |
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*/ |
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protected static $etag = null; |
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/** |
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* @config |
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*/ |
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private static $cache_ajax_requests = true; |
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/** |
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* Turns a local system filename into a URL by comparing it to the script |
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* filename. |
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* |
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* @param string |
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*/ |
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public static function filename2url($filename) { |
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$slashPos = -1; |
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while(($slashPos = strpos($filename, "/", $slashPos+1)) !== false) { |
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if(substr($filename, 0, $slashPos) == substr($_SERVER['SCRIPT_FILENAME'],0,$slashPos)) { |
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$commonLength = $slashPos; |
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} else { |
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break; |
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} |
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} |
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$urlBase = substr( |
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$_SERVER['PHP_SELF'], |
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0, |
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-(strlen($_SERVER['SCRIPT_FILENAME']) - $commonLength) |
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); |
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$url = $urlBase . substr($filename, $commonLength); |
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$protocol = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off') ? "https" : "http"; |
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// Count the number of extra folders the script is in. |
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// $prefix = str_repeat("../", substr_count(substr($_SERVER[SCRIPT_FILENAME],$commonBaseLength))); |
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return "$protocol://". $_SERVER['HTTP_HOST'] . $url; |
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} |
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/** |
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* Turn all relative URLs in the content to absolute URLs |
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*/ |
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public static function absoluteURLs($html) { |
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$html = str_replace('$CurrentPageURL', $_SERVER['REQUEST_URI'], $html); |
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return HTTP::urlRewriter($html, function($url) { |
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//no need to rewrite, if uri has a protocol (determined here by existence of reserved URI character ":") |
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if(preg_match('/^\w+:/', $url)){ |
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return $url; |
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} |
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return Director::absoluteURL($url, true); |
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}); |
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} |
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/** |
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* Rewrite all the URLs in the given content, evaluating the given string as PHP code. |
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* |
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* Put $URL where you want the URL to appear, however, you can't embed $URL in strings |
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* Some example code: |
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* <ul> |
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* <li><code>'"../../" . $URL'</code></li> |
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* <li><code>'myRewriter($URL)'</code></li> |
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* <li><code>'(substr($URL,0,1)=="/") ? "../" . substr($URL,1) : $URL'</code></li> |
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* </ul> |
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* |
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* As of 3.2 $code should be a callable which takes a single parameter and returns |
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* the rewritten URL. e.g. |
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* |
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* <code> |
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* function($url) { |
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* return Director::absoluteURL($url, true); |
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* } |
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* </code> |
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* |
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* @param string $content The HTML to search for links to rewrite |
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* @param string|callable $code Either a string that can evaluate to an expression |
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* to rewrite links (depreciated), or a callable that takes a single |
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* parameter and returns the rewritten URL |
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* @return The content with all links rewritten as per the logic specified in $code |
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*/ |
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public static function urlRewriter($content, $code) { |
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if(!is_callable($code)) { |
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Deprecation::notice('4.0', 'HTTP::urlRewriter expects a callable as the second parameter'); |
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} |
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// Replace attributes |
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$attribs = array("src","background","a" => "href","link" => "href", "base" => "href"); |
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foreach($attribs as $tag => $attrib) { |
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if(!is_numeric($tag)) $tagPrefix = "$tag "; |
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else $tagPrefix = ""; |
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$regExps[] = "/(<{$tagPrefix}[^>]*$attrib *= *\")([^\"]*)(\")/i"; |
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$regExps[] = "/(<{$tagPrefix}[^>]*$attrib *= *')([^']*)(')/i"; |
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$regExps[] = "/(<{$tagPrefix}[^>]*$attrib *= *)([^\"' ]*)( )/i"; |
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} |
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// Replace css styles |
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// @todo - http://www.css3.info/preview/multiple-backgrounds/ |
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$styles = array('background-image', 'background', 'list-style-image', 'list-style', 'content'); |
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foreach($styles as $style) { |
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$regExps[] = "/($style:[^;]*url *\(\")([^\"]+)(\"\))/i"; |
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$regExps[] = "/($style:[^;]*url *\(')([^']+)('\))/i"; |
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$regExps[] = "/($style:[^;]*url *\()([^\"\)')]+)(\))/i"; |
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} |
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// Callback for regexp replacement |
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$callback = function($matches) use($code) { |
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if(is_callable($code)) { |
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$rewritten = $code($matches[2]); |
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} else { |
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// Expose the $URL variable to be used by the $code expression |
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$URL = $matches[2]; |
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$rewritten = eval("return ($code);"); |
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} |
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return $matches[1] . $rewritten . $matches[3]; |
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}; |
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// Execute each expression |
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foreach($regExps as $regExp) { |
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$content = preg_replace_callback($regExp, $callback, $content); |
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} |
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return $content; |
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} |
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/** |
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* Will try to include a GET parameter for an existing URL, |
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* preserving existing parameters and fragments. |
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* If no URL is given, falls back to $_SERVER['REQUEST_URI']. |
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* Uses parse_url() to dissect the URL, and http_build_query() to reconstruct it |
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* with the additional parameter. Converts any '&' (ampersand) |
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* URL parameter separators to the more XHTML compliant '&'. |
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* |
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* CAUTION: If the URL is determined to be relative, |
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* it is prepended with Director::absoluteBaseURL(). |
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* This method will always return an absolute URL because |
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* Director::makeRelative() can lead to inconsistent results. |
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* |
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* @param String $varname |
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* @param String $varvalue |
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* @param String $currentURL Relative or absolute URL (Optional). |
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* @param String $separator Separator for http_build_query(). (Optional). |
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* @return String Absolute URL |
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*/ |
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public static function setGetVar($varname, $varvalue, $currentURL = null, $separator = '&') { |
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$uri = $currentURL ? $currentURL : Director::makeRelative($_SERVER['REQUEST_URI']); |
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$isRelative = false; |
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// We need absolute URLs for parse_url() |
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if(Director::is_relative_url($uri)) { |
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$uri = Director::absoluteBaseURL() . $uri; |
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$isRelative = true; |
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} |
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// try to parse uri |
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$parts = parse_url($uri); |
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if(!$parts) { |
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throw new InvalidArgumentException("Can't parse URL: " . $uri); |
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} |
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// Parse params and add new variable |
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$params = array(); |
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if(isset($parts['query'])) parse_str($parts['query'], $params); |
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$params[$varname] = $varvalue; |
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// Generate URI segments and formatting |
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$scheme = (isset($parts['scheme'])) ? $parts['scheme'] : 'http'; |
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$user = (isset($parts['user']) && $parts['user'] != '') ? $parts['user'] : ''; |
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if($user != '') { |
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// format in either user:[email protected] or [email protected] |
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$user .= (isset($parts['pass']) && $parts['pass'] != '') ? ':' . $parts['pass'] . '@' : '@'; |
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} |
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$host = (isset($parts['host'])) ? $parts['host'] : ''; |
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$port = (isset($parts['port']) && $parts['port'] != '') ? ':'.$parts['port'] : ''; |
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$path = (isset($parts['path']) && $parts['path'] != '') ? $parts['path'] : ''; |
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// handle URL params which are existing / new |
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$params = ($params) ? '?' . http_build_query($params, null, $separator) : ''; |
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// keep fragments (anchors) intact. |
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$fragment = (isset($parts['fragment']) && $parts['fragment'] != '') ? '#'.$parts['fragment'] : ''; |
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// Recompile URI segments |
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$newUri = $scheme . '://' . $user . $host . $port . $path . $params . $fragment; |
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if($isRelative) return Director::makeRelative($newUri); |
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return $newUri; |
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} |
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public static function RAW_setGetVar($varname, $varvalue, $currentURL = null) { |
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$url = self::setGetVar($varname, $varvalue, $currentURL); |
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return Convert::xml2raw($url); |
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} |
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/** |
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* Search for all tags with a specific attribute, then return the value of that attribute in a flat array. |
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* |
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* @param string $content |
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* @param array $attributes an array of tags to attributes, for example "[a] => 'href', [div] => 'id'" |
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* @return array |
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*/ |
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public static function findByTagAndAttribute($content, $attributes) { |
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$regexes = array(); |
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foreach($attributes as $tag => $attribute) { |
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$regexes[] = "/<{$tag} [^>]*$attribute *= *([\"'])(.*?)\\1[^>]*>/i"; |
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$regexes[] = "/<{$tag} [^>]*$attribute *= *([^ \"'>]+)/i"; |
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} |
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$result = array(); |
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if($regexes) foreach($regexes as $regex) { |
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if(preg_match_all($regex, $content, $matches)) { |
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$result = array_merge_recursive($result, (isset($matches[2]) ? $matches[2] : $matches[1])); |
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} |
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} |
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return count($result) ? $result : null; |
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} |
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public static function getLinksIn($content) { |
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return self::findByTagAndAttribute($content, array("a" => "href")); |
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} |
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public static function getImagesIn($content) { |
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return self::findByTagAndAttribute($content, array("img" => "src")); |
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} |
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/** |
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* Get the MIME type based on a file's extension. |
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* |
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* If the finfo class exists in PHP, and the file actually exists, then use that |
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* extension, otherwise fallback to a list of commonly known MIME types. |
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* |
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* @uses finfo |
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* @param string $filename Relative path to filename from project root, e.g. "mysite/tests/file.csv" |
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* @return string MIME type |
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*/ |
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public static function get_mime_type($filename) { |
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// If the finfo module is compiled into PHP, use it. |
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$path = BASE_PATH . DIRECTORY_SEPARATOR . $filename; |
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if(class_exists('finfo') && file_exists($path)) { |
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$finfo = new finfo(FILEINFO_MIME_TYPE); |
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return $finfo->file($path); |
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} |
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// Fallback to use the list from the HTTP.yml configuration and rely on the file extension |
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// to get the file mime-type |
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$ext = File::get_file_extension($filename); |
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// Get the mime-types |
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$mimeTypes = Config::inst()->get('HTTP', 'MimeTypes'); |
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// The mime type doesn't exist |
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if(!isset($mimeTypes[$ext])) { |
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return 'application/unknown'; |
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} |
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return $mimeTypes[$ext]; |
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} |
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/** |
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* Set the maximum age of this page in web caches, in seconds |
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*/ |
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public static function set_cache_age($age) { |
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self::$cache_age = $age; |
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} |
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public static function register_modification_date($dateString) { |
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$timestamp = strtotime($dateString); |
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if($timestamp > self::$modification_date) |
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self::$modification_date = $timestamp; |
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} |
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public static function register_modification_timestamp($timestamp) { |
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if($timestamp > self::$modification_date) |
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self::$modification_date = $timestamp; |
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} |
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public static function register_etag($etag) { |
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self::$etag = $etag; |
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} |
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/** |
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* Add the appropriate caching headers to the response, including If-Modified-Since / 304 handling. |
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* Note that setting HTTP::$cache_age will overrule any cache headers set by PHP's |
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* session_cache_limiter functionality. It is your responsibility to ensure only cacheable data |
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* is in fact cached, and HTTP::$cache_age isn't set when the HTTP body contains session-specific content. |
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* |
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* @param SS_HTTPResponse $body The SS_HTTPResponse object to augment. Omitted the argument or passing a string is |
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* deprecated; in these cases, the headers are output directly. |
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*/ |
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public static function add_cache_headers($body = null) { |
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$cacheAge = self::$cache_age; |
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// Validate argument |
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if($body && !($body instanceof SS_HTTPResponse)) { |
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user_error("HTTP::add_cache_headers() must be passed an SS_HTTPResponse object", E_USER_WARNING); |
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$body = null; |
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} |
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// Development sites have frequently changing templates; this can get stuffed up by the code |
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// below. |
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if(Director::isDev()) $cacheAge = 0; |
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// The headers have been sent and we don't have an SS_HTTPResponse object to attach things to; no point in |
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// us trying. |
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if(headers_sent() && !$body) return; |
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// Populate $responseHeaders with all the headers that we want to build |
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$responseHeaders = array(); |
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$config = Config::inst(); |
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$cacheControlHeaders = Config::inst()->get('HTTP', 'cache_control'); |
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// currently using a config setting to cancel this, seems to be so that the CMS caches ajax requests |
342
|
|
|
if(function_exists('apache_request_headers') && $config->get(get_called_class(), 'cache_ajax_requests')) { |
343
|
|
|
$requestHeaders = array_change_key_case(apache_request_headers(), CASE_LOWER); |
344
|
|
|
|
345
|
|
|
if(isset($requestHeaders['x-requested-with']) && $requestHeaders['x-requested-with']=='XMLHttpRequest') { |
346
|
|
|
$cacheAge = 0; |
347
|
|
|
} |
348
|
|
|
} |
349
|
|
|
|
350
|
|
|
if($cacheAge > 0) { |
351
|
|
|
$cacheControlHeaders['max-age'] = self::$cache_age; |
352
|
|
|
|
353
|
|
|
// Set empty pragma to avoid PHP's session_cache_limiter adding conflicting caching information, |
354
|
|
|
// defaulting to "nocache" on most PHP configurations (see http://php.net/session_cache_limiter). |
355
|
|
|
// Since it's a deprecated HTTP 1.0 option, all modern HTTP clients and proxies should |
356
|
|
|
// prefer the caching information indicated through the "Cache-Control" header. |
357
|
|
|
$responseHeaders["Pragma"] = ""; |
358
|
|
|
|
359
|
|
|
// To do: User-Agent should only be added in situations where you *are* actually |
360
|
|
|
// varying according to user-agent. |
361
|
|
|
$vary = $config->get('HTTP', 'vary'); |
362
|
|
|
if ($vary && strlen($vary)) { |
363
|
|
|
$responseHeaders['Vary'] = $vary; |
364
|
|
|
} |
365
|
|
|
} |
366
|
|
|
else { |
367
|
|
|
if($body) { |
368
|
|
|
// Grab header for checking. Unfortunately HTTPRequest uses a mistyped variant. |
369
|
|
|
$contentDisposition = $body->getHeader('Content-disposition'); |
370
|
|
|
if (!$contentDisposition) $contentDisposition = $body->getHeader('Content-Disposition'); |
371
|
|
|
} |
372
|
|
|
|
373
|
|
|
if( |
374
|
|
|
$body && |
375
|
|
|
Director::is_https() && |
376
|
|
|
isset($_SERVER['HTTP_USER_AGENT']) && |
377
|
|
|
strstr($_SERVER['HTTP_USER_AGENT'], 'MSIE')==true && |
|
|
|
|
378
|
|
|
strstr($contentDisposition, 'attachment;')==true |
|
|
|
|
379
|
|
|
) { |
380
|
|
|
// IE6-IE8 have problems saving files when https and no-cache are used |
381
|
|
|
// (http://support.microsoft.com/kb/323308) |
382
|
|
|
// Note: this is also fixable by ticking "Do not save encrypted pages to disk" in advanced options. |
383
|
|
|
$cacheControlHeaders['max-age'] = 3; |
384
|
|
|
|
385
|
|
|
// Set empty pragma to avoid PHP's session_cache_limiter adding conflicting caching information, |
386
|
|
|
// defaulting to "nocache" on most PHP configurations (see http://php.net/session_cache_limiter). |
387
|
|
|
// Since it's a deprecated HTTP 1.0 option, all modern HTTP clients and proxies should |
388
|
|
|
// prefer the caching information indicated through the "Cache-Control" header. |
389
|
|
|
$responseHeaders["Pragma"] = ""; |
390
|
|
|
} else { |
391
|
|
|
$cacheControlHeaders['no-cache'] = "true"; |
392
|
|
|
$cacheControlHeaders['no-store'] = "true"; |
393
|
|
|
} |
394
|
|
|
} |
395
|
|
|
|
396
|
|
|
foreach($cacheControlHeaders as $header => $value) { |
|
|
|
|
397
|
|
|
if(is_null($value)) { |
398
|
|
|
unset($cacheControlHeaders[$header]); |
399
|
|
|
} elseif((is_bool($value) && $value) || $value === "true") { |
400
|
|
|
$cacheControlHeaders[$header] = $header; |
401
|
|
|
} else { |
402
|
|
|
$cacheControlHeaders[$header] = $header."=".$value; |
403
|
|
|
} |
404
|
|
|
} |
405
|
|
|
|
406
|
|
|
$responseHeaders['Cache-Control'] = implode(', ', $cacheControlHeaders); |
407
|
|
|
unset($cacheControlHeaders, $header, $value); |
408
|
|
|
|
409
|
|
|
if(self::$modification_date && $cacheAge > 0) { |
410
|
|
|
$responseHeaders["Last-Modified"] = self::gmt_date(self::$modification_date); |
411
|
|
|
|
412
|
|
|
// Chrome ignores Varies when redirecting back (http://code.google.com/p/chromium/issues/detail?id=79758) |
413
|
|
|
// which means that if you log out, you get redirected back to a page which Chrome then checks against |
414
|
|
|
// last-modified (which passes, getting a 304) |
415
|
|
|
// when it shouldn't be trying to use that page at all because it's the "logged in" version. |
416
|
|
|
// By also using and etag that includes both the modification date and all the varies |
417
|
|
|
// values which we also check against we can catch this and not return a 304 |
418
|
|
|
$etagParts = array(self::$modification_date, serialize($_COOKIE)); |
419
|
|
|
$etagParts[] = Director::is_https() ? 'https' : 'http'; |
420
|
|
|
if (isset($_SERVER['HTTP_USER_AGENT'])) $etagParts[] = $_SERVER['HTTP_USER_AGENT']; |
421
|
|
|
if (isset($_SERVER['HTTP_ACCEPT'])) $etagParts[] = $_SERVER['HTTP_ACCEPT']; |
422
|
|
|
|
423
|
|
|
$etag = sha1(implode(':', $etagParts)); |
424
|
|
|
$responseHeaders["ETag"] = $etag; |
425
|
|
|
|
426
|
|
|
// 304 response detection |
427
|
|
|
if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) { |
428
|
|
|
$ifModifiedSince = strtotime(stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE'])); |
429
|
|
|
|
430
|
|
|
// As above, only 304 if the last request had all the same varies values |
431
|
|
|
// (or the etag isn't passed as part of the request - but with chrome it always is) |
432
|
|
|
$matchesEtag = !isset($_SERVER['HTTP_IF_NONE_MATCH']) || $_SERVER['HTTP_IF_NONE_MATCH'] == $etag; |
433
|
|
|
|
434
|
|
|
if($ifModifiedSince >= self::$modification_date && $matchesEtag) { |
435
|
|
|
if($body) { |
436
|
|
|
$body->setStatusCode(304); |
437
|
|
|
$body->setBody(''); |
438
|
|
|
} else { |
439
|
|
|
header('HTTP/1.0 304 Not Modified'); |
440
|
|
|
die(); |
441
|
|
|
} |
442
|
|
|
} |
443
|
|
|
} |
444
|
|
|
|
445
|
|
|
$expires = time() + $cacheAge; |
446
|
|
|
$responseHeaders["Expires"] = self::gmt_date($expires); |
447
|
|
|
} |
448
|
|
|
|
449
|
|
|
if(self::$etag) { |
450
|
|
|
$responseHeaders['ETag'] = self::$etag; |
451
|
|
|
} |
452
|
|
|
|
453
|
|
|
// Now that we've generated them, either output them or attach them to the SS_HTTPResponse as appropriate |
454
|
|
|
foreach($responseHeaders as $k => $v) { |
455
|
|
|
if($body) { |
456
|
|
|
// Set the header now if it's not already set. |
457
|
|
|
if ($body->getHeader($k) === null) { |
458
|
|
|
$body->addHeader($k, $v); |
459
|
|
|
} |
460
|
|
|
} elseif(!headers_sent()) { |
461
|
|
|
header("$k: $v"); |
462
|
|
|
} |
463
|
|
|
} |
464
|
|
|
} |
465
|
|
|
|
466
|
|
|
|
467
|
|
|
/** |
468
|
|
|
* Return an {@link http://www.faqs.org/rfcs/rfc2822 RFC 2822} date in the |
469
|
|
|
* GMT timezone (a timestamp is always in GMT: the number of seconds |
470
|
|
|
* since January 1 1970 00:00:00 GMT) |
471
|
|
|
*/ |
472
|
|
|
public static function gmt_date($timestamp) { |
473
|
|
|
return gmdate('D, d M Y H:i:s', $timestamp) . ' GMT'; |
474
|
|
|
} |
475
|
|
|
|
476
|
|
|
/* |
477
|
|
|
* Return static variable cache_age in second |
478
|
|
|
*/ |
479
|
|
|
public static function get_cache_age() { |
480
|
|
|
return self::$cache_age; |
481
|
|
|
} |
482
|
|
|
|
483
|
|
|
} |
484
|
|
|
|
485
|
|
|
|
486
|
|
|
|
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: