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htmlpurifier/library/HTMLPurifier/ChildDef/Table.php
Edward Z. Yang e41af46a8b Fix broken table content model, easily seen in XHTML1.1
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
2011-12-26 14:49:26 +08:00

228 lines
9.2 KiB
PHP

<?php
/**
* Definition for tables. The general idea is to extract out all of the
* essential bits, and then reconstruct it later.
*
* This is a bit confusing, because the DTDs and the W3C
* validators seem to disagree on the appropriate definition. The
* DTD claims:
*
* (CAPTION?, (COL*|COLGROUP*), THEAD?, TFOOT?, TBODY+)
*
* But actually, the HTML4 spec then has this to say:
*
* The TBODY start tag is always required except when the table
* contains only one table body and no table head or foot sections.
* The TBODY end tag may always be safely omitted.
*
* So the DTD is kind of wrong. The validator is, unfortunately, kind
* of on crack.
*
* The definition changed again in XHTML1.1; and in my opinion, this
* formulation makes the most sense.
*
* caption?, ( col* | colgroup* ), (( thead?, tfoot?, tbody+ ) | ( tr+ ))
*
* Essentially, we have two modes: thead/tfoot/tbody mode, and tr mode.
* If we encounter a thead, tfoot or tbody, we are placed in the former
* mode, and we *must* wrap any stray tr segments with a tbody. But if
* we don't run into any of them, just have tr tags is OK.
*/
class HTMLPurifier_ChildDef_Table extends HTMLPurifier_ChildDef
{
public $allow_empty = false;
public $type = 'table';
public $elements = array('tr' => true, 'tbody' => true, 'thead' => true,
'tfoot' => true, 'caption' => true, 'colgroup' => true, 'col' => true);
public function __construct() {}
public function validateChildren($tokens_of_children, $config, $context) {
if (empty($tokens_of_children)) return false;
// this ensures that the loop gets run one last time before closing
// up. It's a little bit of a hack, but it works! Just make sure you
// get rid of the token later.
$tokens_of_children[] = false;
// only one of these elements is allowed in a table
$caption = false;
$thead = false;
$tfoot = false;
// as many of these as you want
$cols = array();
$content = array();
$nesting = 0; // current depth so we can determine nodes
$is_collecting = false; // are we globbing together tokens to package
// into one of the collectors?
$collection = array(); // collected nodes
$tag_index = 0; // the first node might be whitespace,
// so this tells us where the start tag is
$tbody_mode = false; // if true, then we need to wrap any stray
// <tr>s with a <tbody>.
foreach ($tokens_of_children as $token) {
$is_child = ($nesting == 0);
if ($token === false) {
// terminating sequence started
} elseif ($token instanceof HTMLPurifier_Token_Start) {
$nesting++;
} elseif ($token instanceof HTMLPurifier_Token_End) {
$nesting--;
}
// handle node collection
if ($is_collecting) {
if ($is_child) {
// okay, let's stash the tokens away
// first token tells us the type of the collection
switch ($collection[$tag_index]->name) {
case 'tbody':
$tbody_mode = true;
case 'tr':
$content[] = $collection;
break;
case 'caption':
if ($caption !== false) break;
$caption = $collection;
break;
case 'thead':
case 'tfoot':
$tbody_mode = true;
// XXX This breaks rendering properties with
// Firefox, which never floats a <thead> to
// the top. Ever. (Our scheme will float the
// first <thead> to the top.) So maybe
// <thead>s that are not first should be
// turned into <tbody>? Very tricky, indeed.
// access the appropriate variable, $thead or $tfoot
$var = $collection[$tag_index]->name;
if ($$var === false) {
$$var = $collection;
} else {
// Oops, there's a second one! What
// should we do? Current behavior is to
// transmutate the first and last entries into
// tbody tags, and then put into content.
// Maybe a better idea is to *attach
// it* to the existing thead or tfoot?
// We don't do this, because Firefox
// doesn't float an extra tfoot to the
// bottom like it does for the first one.
$collection[$tag_index]->name = 'tbody';
$collection[count($collection)-1]->name = 'tbody';
$content[] = $collection;
}
break;
case 'colgroup':
$cols[] = $collection;
break;
}
$collection = array();
$is_collecting = false;
$tag_index = 0;
} else {
// add the node to the collection
$collection[] = $token;
}
}
// terminate
if ($token === false) break;
if ($is_child) {
// determine what we're dealing with
if ($token->name == 'col') {
// the only empty tag in the possie, we can handle it
// immediately
$cols[] = array_merge($collection, array($token));
$collection = array();
$tag_index = 0;
continue;
}
switch($token->name) {
case 'caption':
case 'colgroup':
case 'thead':
case 'tfoot':
case 'tbody':
case 'tr':
$is_collecting = true;
$collection[] = $token;
continue;
default:
if (!empty($token->is_whitespace)) {
$collection[] = $token;
$tag_index++;
}
continue;
}
}
}
if (empty($content)) return false;
$ret = array();
if ($caption !== false) $ret = array_merge($ret, $caption);
if ($cols !== false) foreach ($cols as $token_array) $ret = array_merge($ret, $token_array);
if ($thead !== false) $ret = array_merge($ret, $thead);
if ($tfoot !== false) $ret = array_merge($ret, $tfoot);
if ($tbody_mode) {
// a little tricky, since the start of the collection may be
// whitespace
$inside_tbody = false;
foreach ($content as $token_array) {
// find the starting token
foreach ($token_array as $t) {
if ($t->name === 'tr' || $t->name === 'tbody') {
break;
}
} // iterator variable carries over
if ($t->name === 'tr') {
if ($inside_tbody) {
$ret = array_merge($ret, $token_array);
} else {
$ret[] = new HTMLPurifier_Token_Start('tbody');
$ret = array_merge($ret, $token_array);
$inside_tbody = true;
}
} elseif ($t->name === 'tbody') {
if ($inside_tbody) {
$ret[] = new HTMLPurifier_Token_End('tbody');
$inside_tbody = false;
$ret = array_merge($ret, $token_array);
} else {
$ret = array_merge($ret, $token_array);
}
} else {
trigger_error("tr/tbody in content invariant failed in Table ChildDef", E_USER_ERROR);
}
}
if ($inside_tbody) {
$ret[] = new HTMLPurifier_Token_End('tbody');
}
} else {
foreach ($content as $token_array) {
// invariant: everything in here is <tr>s
$ret = array_merge($ret, $token_array);
}
}
if (!empty($collection) && $is_collecting == false){
// grab the trailing space
$ret = array_merge($ret, $collection);
}
array_pop($tokens_of_children); // remove phantom token
return ($ret === $tokens_of_children) ? true : $ret;
}
}
// vim: et sw=4 sts=4