/cms/openid/Services/Yadis/ParseHTML.php
PHP | 270 lines | 136 code | 35 blank | 99 comment | 14 complexity | 965f7130645e3bf29164c8bc92fd26bd MD5 | raw file
- <?php
- /**
- * This is the HTML pseudo-parser for the Yadis library.
- *
- * PHP versions 4 and 5
- *
- * LICENSE: See the COPYING file included in this distribution.
- *
- * @package Yadis
- * @author JanRain, Inc. <openid@janrain.com>
- * @copyright 2005 Janrain, Inc.
- * @license http://www.gnu.org/copyleft/lesser.html LGPL
- */
- /**
- * This class is responsible for scanning an HTML string to find META
- * tags and their attributes. This is used by the Yadis discovery
- * process. This class must be instantiated to be used.
- *
- * @package Yadis
- */
- class Services_Yadis_ParseHTML {
- /**
- * @access private
- */
- var $_re_flags = "si";
- /**
- * @access private
- */
- var $_tag_expr = "<%s\b(?!:)([^>]*?)(?:\/>|>(.*?)(?:<\/?%s\s*>|\Z))";
- /**
- * @access private
- */
- var $_close_tag_expr = "<\/?%s\s*>";
- /**
- * @access private
- */
- var $_removed_re =
- "<!--.*?-->|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>";
- /**
- * @access private
- */
- var $_attr_find = '\b([-\w]+)=("[^"]*"|\'[^\']*\'|[^\'"\s\/<>]+)';
- function Services_Yadis_ParseHTML()
- {
- $this->_meta_find = sprintf("/<meta\b(?!:)([^>]*)(?!<)>/%s",
- $this->_re_flags);
- $this->_removed_re = sprintf("/%s/%s",
- $this->_removed_re,
- $this->_re_flags);
- $this->_attr_find = sprintf("/%s/%s",
- $this->_attr_find,
- $this->_re_flags);
- $this->_entity_replacements = array(
- 'amp' => '&',
- 'lt' => '<',
- 'gt' => '>',
- 'quot' => '"'
- );
- $this->_ent_replace =
- sprintf("&(%s);", implode("|",
- $this->_entity_replacements));
- }
- /**
- * Replace HTML entities (amp, lt, gt, and quot) as well as
- * numeric entities (e.g. #x9f;) with their actual values and
- * return the new string.
- *
- * @access private
- * @param string $str The string in which to look for entities
- * @return string $new_str The new string entities decoded
- */
- function replaceEntities($str)
- {
- foreach ($this->_entity_replacements as $old => $new) {
- $str = preg_replace(sprintf("/&%s;/", $old), $new, $str);
- }
- // Replace numeric entities because html_entity_decode doesn't
- // do it for us.
- $str = preg_replace('~&#x([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $str);
- $str = preg_replace('~&#([0-9]+);~e', 'chr(\\1)', $str);
- return $str;
- }
- /**
- * Strip single and double quotes off of a string, if they are
- * present.
- *
- * @access private
- * @param string $str The original string
- * @return string $new_str The new string with leading and
- * trailing quotes removed
- */
- function removeQuotes($str)
- {
- $matches = array();
- $double = '/^"(.*)"$/';
- $single = "/^\'(.*)\'$/";
- if (preg_match($double, $str, $matches)) {
- return $matches[1];
- } else if (preg_match($single, $str, $matches)) {
- return $matches[1];
- } else {
- return $str;
- }
- }
- /**
- * Create a regular expression that will match an opening (and
- * optional) closing tag of a given name.
- *
- * @access private
- * @param string $tag_name The tag name to match
- * @param array $close_tags An array of tag names which also
- * constitute closing of the original tag
- * @return string $regex A regular expression string to be used
- * in, say, preg_match.
- */
- function tagMatcher($tag_name, $close_tags = null)
- {
- if ($close_tags) {
- $options = implode("|", array_merge(array($tag_name), $close_tags));
- $closer = sprintf("(?:%s)", $options);
- } else {
- $closer = $tag_name;
- }
- $expr = sprintf($this->_tag_expr, $tag_name, $closer);
- return sprintf("/%s/%s", $expr, $this->_re_flags);
- }
- /**
- * @access private
- */
- function htmlFind($str)
- {
- return $this->tagMatcher('html', array('body'));
- }
- /**
- * @access private
- */
- function headFind()
- {
- return $this->tagMatcher('head', array('body'));
- }
- /**
- * Given an HTML document string, this finds all the META tags in
- * the document, provided they are found in the
- * <HTML><HEAD>...</HEAD> section of the document. The <HTML> tag
- * may be missing.
- *
- * @access private
- * @param string $html_string An HTMl document string
- * @return array $tag_list Array of tags; each tag is an array of
- * attribute -> value.
- */
- function getMetaTags($html_string)
- {
- $stripped = preg_replace($this->_removed_re,
- "",
- $html_string);
- // Look for the closing body tag.
- $body_closer = sprintf($this->_close_tag_expr, 'body');
- $body_matches = array();
- preg_match($body_closer, $html_string, $body_matches,
- PREG_OFFSET_CAPTURE);
- if ($body_matches) {
- $html_string = substr($html_string, 0, $body_matches[0][1]);
- }
- // Look for the opening body tag, and discard everything after
- // that tag.
- $body_re = $this->tagMatcher('body');
- $body_matches = array();
- preg_match($body_re, $html_string, $body_matches, PREG_OFFSET_CAPTURE);
- if ($body_matches) {
- $html_string = substr($html_string, 0, $body_matches[0][1]);
- }
- // If an HTML tag is found at all, it must be in the right
- // order; else, it may be missing (which is a case we allow
- // for).
- $html_re = $this->tagMatcher('html', array('body'));
- preg_match($html_re, $html_string, $html_matches);
- if ($html_matches) {
- $html = $html_matches[0];
- } else {
- $html = $html_string;
- }
- // Try to find the <HEAD> tag.
- $head_re = $this->headFind();
- $head_matches = array();
- if (!preg_match($head_re, $html, $head_matches)) {
- return array();
- }
- $link_data = array();
- $link_matches = array();
- if (!preg_match_all($this->_meta_find, $head_matches[0],
- $link_matches)) {
- return array();
- }
- foreach ($link_matches[0] as $link) {
- $attr_matches = array();
- preg_match_all($this->_attr_find, $link, $attr_matches);
- $link_attrs = array();
- foreach ($attr_matches[0] as $index => $full_match) {
- $name = $attr_matches[1][$index];
- $value = $this->replaceEntities(
- $this->removeQuotes($attr_matches[2][$index]));
- $link_attrs[strtolower($name)] = $value;
- }
- $link_data[] = $link_attrs;
- }
- return $link_data;
- }
- /**
- * Looks for a META tag with an "http-equiv" attribute whose value
- * is one of ("x-xrds-location", "x-yadis-location"), ignoring
- * case. If such a META tag is found, its "content" attribute
- * value is returned.
- *
- * @param string $html_string An HTML document in string format
- * @return mixed $content The "content" attribute value of the
- * META tag, if found, or null if no such tag was found.
- */
- function getHTTPEquiv($html_string)
- {
- $meta_tags = $this->getMetaTags($html_string);
- if ($meta_tags) {
- foreach ($meta_tags as $tag) {
- if (array_key_exists('http-equiv', $tag) &&
- (in_array(strtolower($tag['http-equiv']),
- array('x-xrds-location', 'x-yadis-location'))) &&
- array_key_exists('content', $tag)) {
- return $tag['content'];
- }
- }
- }
- return null;
- }
- }
- ?>