strtok()的问题

Question

我和这个搏斗已经有一段时间了。我知道这是很多代码要看，但我不知道问题的所在，似乎不能缩小它。我会赏金的。

我编写这个类是为了解析bbcode。它主要使用strtok()，除非您将两个标记放在一起，否则类工作得很好，而且我无法在我的一生中找出原因。

例如，[b] [i]test1[/i] [/b]会导致<strong> <em>test1</em> </strong>。然而，[b][i]test1[/i][/b]导致了<strong>i]test1/b]</strong>。最后一个</strong>标记仅在其中，因为解析器自动关闭在字符串中找不到结束标记的标记。它在某种程度上完全忽略了[i]和[/b]标记。

这是类以及它用于设置各种bbcode的一个子类。子类基本上只是一个没有行为的数据结构。

<?php
    // beware images can contain any url/any get request. beware of csrf
    class Lev_TextProcessor_Extension_BbCode {

        protected $elements = array();
        protected $openTags = array();

        public function __construct() {
            $this->elements['b'] = new Lev_TextProcessor_Extension_BbCode_Element('<strong>', '</strong>');
            $this->elements['i'] = new Lev_TextProcessor_Extension_BbCode_Element('<em>', '</em>');
            $this->elements['u'] = new Lev_TextProcessor_Extension_BbCode_Element('<span style="text-decoration: underline;">', '</span>');
            $this->elements['s'] = new Lev_TextProcessor_Extension_BbCode_Element('<span style="text-decoration: line-through;">', '</span>');
            $this->elements['size'] = new Lev_TextProcessor_Extension_BbCode_Element('<span style="font-size: ', '</span>', 'px;">');
            $this->elements['color'] = new Lev_TextProcessor_Extension_BbCode_Element('<span style="color: ', '</span>', ';">');
            $this->elements['center'] = new Lev_TextProcessor_Extension_BbCode_Element('<div style="text-align: center;">', '</div>', '', true, true, false);
            $this->elements['url'] = new Lev_TextProcessor_Extension_BbCode_Element('<a href="', '</a>', '">');
            $this->elements['email'] = new Lev_TextProcessor_Extension_BbCode_Element('<a href="mailto:', '</a>', '">');
            $this->elements['img'] = new Lev_TextProcessor_Extension_BbCode_Element('<img src="', '" alt="" />', '', false, false, true);
            $this->elements['youtube'] = new Lev_TextProcessor_Extension_BbCode_Element('<object width="400" height="325"><param name="movie" value="http://www.youtube.com/v/{param}"></param><embed src="http://www.youtube.com/v/', '" type="application/x-shockwave-flash" width="400" height="325"></embed></object>', '', false, false, false);
            $this->elements['code'] = new Lev_TextProcessor_Extension_BbCode_Element('<pre><code>', '</code></pre>', '', true, false, false);
        }

        public function processText($input) {
            // pre processing
            $input = htmlspecialchars($input, ENT_NOQUOTES);
            $input = nl2br($input);
            $input = str_replace(array("\n", "\r"), '', $input);
            // start main processing
            $output = '';
            $allow_child_tags = true;
            $allow_child_quotes = true;

            $string_segment = strtok($input, '[');

            do {
                // check content for quotes
                if ($allow_child_quotes === false) {
                    if (strpos($string_segment, '"') === false) {
                        $output .= $string_segment;
                    }
                } else {
                    // add content to output
                    $output .= $string_segment;
                }

                $tag_contents = strtok(']');

                if (strpos($tag_contents, '/') === 0) {
                    // closing tag
                    $tag = substr($tag_contents, 1);
                    if (isset($this->elements[$tag]) === true && array_search($tag, $this->openTags) !== false) {
                        // tag found
                        do {
                            // close tags till matching tag found
                            $last_open_tag = array_pop($this->openTags);
                            $output .= $this->elements[$last_open_tag]->htmlAfter;
                        } while ($last_open_tag !== $tag);
                        $allow_child_tags = true;
                        $allow_child_quotes = true;
                    }
                } else {
                    // opening tag
                    // separate tag name from argument if there is one
                    $equal_pos = strpos($tag_contents, '=');
                    if ($equal_pos === false) {
                        $tag_name = $tag_contents;
                    } else {
                        $tag_name = substr($tag_contents, 0, $equal_pos);
                        $tag_argument = substr($tag_contents, $equal_pos + 1);
                    }
                    if (isset($this->elements[$tag_name]) === true) {
                        // tag found
                        if (($this->elements[$tag_name]->allowParentTags === true || count($this->openTags) === 0) && $allow_child_tags === true) {
                            // add tag to open tag list and set flags
                            $this->openTags[] = $tag_name;
                            $allow_child_tags = $this->elements[$tag_name]->allowChildTags;
                            $allow_child_quotes = $this->elements[$tag_name]->allowChildQuotes;
                            $output .= $this->elements[$tag_name]->htmlBefore;
                            // if argument exists
                            if ($equal_pos !== false) {
                                if (strpos($tag_argument, '"') === false) {
                                    $output .= $tag_argument;
                                }
                                $output .= $this->elements[$tag_name]->htmlCenter;
                            }
                        }
                    }
                }

                $string_segment = strtok('[');
            } while ($string_segment !== false);
            // close left over tags
            while ($tag = array_pop($this->openTags)) {
                $output .= $this->elements[$tag]->htmlAfter;
            }
            return $output;
        }
    }
?>

<?php

    class Lev_TextProcessor_Extension_BbCode_Element {

        public $htmlBefore;
        public $htmlAfter;
        public $htmlCenter;
        public $allowChildQuotes;
        public $allowChildTags;
        public $allowParentTags;

        public function __construct($html_before, $html_after, $html_center = '', $allow_child_quotes = true, $allow_child_tags = true, $allow_parent_tags = true) {
            if ($allow_child_quotes === false && $allow_child_tags === true) throw new Lev_TextProcessor_Exception('You may not allow child tags if you do not allow child quotes.');
            $this->htmlBefore = $html_before;
            $this->htmlAfter = $html_after;
            $this->htmlCenter = $html_center;
            $this->allowChildQuotes = $allow_child_quotes;
            $this->allowChildTags = $allow_child_tags;
            $this->allowParentTags = $allow_parent_tags;
        }
    }
?>

编辑

通过创建用于令牌化的以下类进行修正。

<?php

    // unlike PHP's strtok() function, this class will not skip over empty tokens.
    class Lev_TextProcessor_Tokenizer {

        protected $string;

        public function __construct($string) {
            $this->string = $string;
        }

        public function getToken($token) {
            $segment_length = strcspn($this->string, $token);
            $token = substr($this->string, 0, $segment_length);
            $this->string = substr($this->string, $segment_length + 1);
            return $token;
        }
    }
?>

Answer 1

虽然我不认为这是真正的解决办法，但这似乎是我要阐明我的观点的唯一方法。

它可能与strtok()的工作方式有关，可以得到您想要的结果。

虽然不完美，但我能够获得接近您预期的结果：

 <?
 $data1 = strtok('[b][i]test1[/i][/b]','[');
 $data2 = strtok(']');
 $data3 = strtok('[');
 $data4 = strtok(']');
 $data5 = strtok('[');
 $data6 = strtok(']');
 var_dump($data1, $data2,$data3, $data4, $data5, $data6);
 /*
  OUTPUT
    string(2) "b]"
    string(1) "i"
    string(5) "test1"
    string(2) "/i"
    string(3) "/b]"
    bool(false)
 * /
 ?>

正如我所说的，这并不完美，但也许看到这一点将有助于您在处理此解决方案的过程中。我个人从未用这种类型的解析来处理BBCode，而是使用preg_match()。