Subversion Repositories Applications.annuaire

<?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 $_removed_re =

           "<!--.*?-->|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>";

    /**

     * @access private

     */

    var $_tag_expr = "<%s%s(?:\s.*?)?%s>";

    /**

     * @access private

     */

    var $_attr_find = '\b([-\w]+)=(".*?"|\'.*?\'|.+?)[\s>]';

    function Services_Yadis_ParseHTML()

    {

        $this->_attr_find = sprintf("/%s/%s",

                                    $this->_attr_find,

                                    $this->_re_flags);

        $this->_removed_re = sprintf("/%s/%s",

                                     $this->_removed_re,

                                     $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

     * or closing tag from a set of names.

     *

     * @access private

     * @param mixed $tag_names Tag names to match

     * @param mixed $close false/0 = no, true/1 = yes, other = maybe

     * @param mixed $self_close false/0 = no, true/1 = yes, other = maybe

     * @return string $regex A regular expression string to be used

     * in, say, preg_match.

     */

    function tagPattern($tag_names, $close, $self_close)

    {

        if (is_array($tag_names)) {

            $tag_names = '(?:'.implode('|',$tag_names).')';

        }

        if ($close) {

            $close = '\/' . (($close == 1)? '' : '?');

        } else {

            $close = '';

        }

        if ($self_close) {

            $self_close = '(?:\/\s*)' . (($self_close == 1)? '' : '?');

        } else {

            $self_close = '';

        }

        $expr = sprintf($this->_tag_expr, $close, $tag_names, $self_close);

        return sprintf("/%s/%s", $expr, $this->_re_flags);

    }

    /**

     * 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)

    {

        $html_string = preg_replace($this->_removed_re,

                                    "",

                                    $html_string);

        $key_tags = array($this->tagPattern('html', false, false),

                          $this->tagPattern('head', false, false),

                          $this->tagPattern('head', true, false),

                          $this->tagPattern('html', true, false),

                          $this->tagPattern(array(

                          'body', 'frameset', 'frame', 'p', 'div',

                          'table','span','a'), 'maybe', 'maybe'));

        $key_tags_pos = array();

        foreach ($key_tags as $pat) {

            $matches = array();

            preg_match($pat, $html_string, $matches, PREG_OFFSET_CAPTURE);

            if($matches) {

                $key_tags_pos[] = $matches[0][1];

            } else {

                $key_tags_pos[] = null;

            }

        }

        // no opening head tag

        if (is_null($key_tags_pos[1])) {

            return array();

        }

        // the effective </head> is the min of the following

        if (is_null($key_tags_pos[2])) {

            $key_tags_pos[2] = strlen($html_string);

        }

        foreach (array($key_tags_pos[3], $key_tags_pos[4]) as $pos) {

            if (!is_null($pos) && $pos < $key_tags_pos[2]) {

                $key_tags_pos[2] = $pos;

            }

        }

        // closing head tag comes before opening head tag

        if ($key_tags_pos[1] > $key_tags_pos[2]) {

            return array();

        }

        // if there is an opening html tag, make sure the opening head tag

        // comes after it

        if (!is_null($key_tags_pos[0]) && $key_tags_pos[1] < $key_tags_pos[0]) {

            return array();

        }

        $html_string = substr($html_string, $key_tags_pos[1], ($key_tags_pos[2]-$key_tags_pos[1]));

        $link_data = array();

        $link_matches = array();

        if (!preg_match_all($this->tagPattern('meta', false, 'maybe'),

                            $html_string, $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;

    }

}

?>