Subversion Repositories Sites.obs-saisons.fr

<?php

/**

 *

 * @author Olivier Laviale

 * @see http://www.weirdog.com/blog/php/un-parser-html-des-plus-leger.html

 *

 */

class WdHTMLParser {

    private $encoding;

    private $matches;

    private $escaped;

    private $opened = array();

    public $malformed;

    public function parse($html, $namespace=NULL, $encoding='utf-8') {

        $this->malformed = false;

        $this->encoding = $encoding;

        // we take care of escaping comments and processing options. they will not be parsed

        // and will end as text nodes

        $html = $this->escapeSpecials($html);

        // in order to create a tree, we first need to split the HTML using the markups,

        // creating a nice flat array of texts and opening and closing markups.

        //

        // the array can be read as follows :

        //

        // i+0 => some text

        // i+1 => '/' for closing markups, nothing otherwise

        // i+2 => the markup it self, without the '<' '>'

        //

        // note that i+2 might end with a '/' indicating an auto-closing markup

        $this->matches = preg_explode('#<(/?)' . $namespace . '([^>]*)>#', $html, -1, PREG_SPLIT_DELIM_CAPTURE);

        // the flat representation is now ready, we can create our tree

        $tree = $this->buildTree();

        // if comments or processing options where escaped, we can

        // safely unescape them now

        if ($this->escaped) {

            $tree = $this->unescapeSpecials($tree);

        }

        return $tree;

    }

    private function escapeSpecials($html) {

        // here we escape comments

        $html = preg_replace_callback('#<\!--.+-->#sU', array($this, 'escapeSpecials_callback'), $html);

        // and processing options

        $html = preg_replace_callback('#<\?.+\?>#sU', array($this, 'escapeSpecials_callback'), $html);

        return $html;

    }

    private function escapeSpecials_callback($m) {

        $this->escaped = true;

        $text = $m[0];

        $text = str_replace(array('<', '>'), array("\x01", "\x02"), $text);

        return $text;

    }

    private function unescapeSpecials($tree) {

        return is_array($tree) ? array_map(array($this, 'unescapeSpecials'), $tree) : str_replace(array("\x01", "\x02"), array('<', '>'), $tree);

    }

    private function buildTree() {

        $nodes = array();

        $i = 0;

        $text = NULL;

        while (($value = array_shift($this->matches)) !== NULL) {

            switch ($i++ % 3) {

                case 0:

                    // if the trimed value is not empty we preserve the value,

                    // otherwise we discard it.

                    if (trim($value)){

                        $nodes[] = $value;

                    }

	                break;

                case 1:

                    $closing = ($value == '/');

	                break;

                case 2:

                    if (substr($value, -1, 1) == '/') {

                        // auto closing

                        $nodes[] = $this->parseMarkup(substr($value, 0, -1));

                    } else if ($closing) {

                        // closing markup

                        $open = array_pop($this->opened);

                        if ($value != $open) {

                            $this->error($value, $open);

                        }

                        return $nodes;

                    } else {

                        // this is an open markup with possible children

                        $node = $this->parseMarkup($value);

                        // push the markup name into the opened markups

                        $this->opened[] = $node['name'];

                        // create the node and parse its children

                        $node['children'] = $this->buildTree($this->matches);

                        $nodes[] = $node;

                    }

                    break;

            }

		}

        return $nodes;

    }

    public function parseMarkup($markup) {

        // get markup's name

        preg_match('#^[^\s]+#', $markup, $matches);

        $name = $matches[0];

        // get markup's arguments

        preg_match_all('#\s+([^=]+)\s*=\s*"([^"]+)"#', $markup, $matches, PREG_SET_ORDER);

        // transform the matches into a nice key/value array

        $args = array();

        foreach ($matches as $m) {

			// we unescape the html entities of the argument's value

            $args[$m[1]] = html_entity_decode($m[2], ENT_QUOTES, $this->encoding);

        }

        return array('name' => $name, 'args' => $args);

    }

    public function error($markup, $expected) {

        $this->malformed = true;

        printf('unexpected closing markup "%s", should be "%s"', $markup, $expected);

    }

}

?>