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Diffstat (limited to 'lib/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php')
| -rw-r--r-- | lib/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php | 328 |
1 files changed, 0 insertions, 328 deletions
diff --git a/lib/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php b/lib/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php deleted file mode 100644 index f81802391..000000000 --- a/lib/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php +++ /dev/null @@ -1,328 +0,0 @@ -<?php - -/** - * Takes a well formed list of tokens and fixes their nesting. - * - * HTML elements dictate which elements are allowed to be their children, - * for example, you can't have a p tag in a span tag. Other elements have - * much more rigorous definitions: tables, for instance, require a specific - * order for their elements. There are also constraints not expressible by - * document type definitions, such as the chameleon nature of ins/del - * tags and global child exclusions. - * - * The first major objective of this strategy is to iterate through all the - * nodes (not tokens) of the list of tokens and determine whether or not - * their children conform to the element's definition. If they do not, the - * child definition may optionally supply an amended list of elements that - * is valid or require that the entire node be deleted (and the previous - * node rescanned). - * - * The second objective is to ensure that explicitly excluded elements of - * an element do not appear in its children. Code that accomplishes this - * task is pervasive through the strategy, though the two are distinct tasks - * and could, theoretically, be seperated (although it's not recommended). - * - * @note Whether or not unrecognized children are silently dropped or - * translated into text depends on the child definitions. - * - * @todo Enable nodes to be bubbled out of the structure. - */ - -class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy -{ - - public function execute($tokens, $config, $context) { - //####################################################################// - // Pre-processing - - // get a copy of the HTML definition - $definition = $config->getHTMLDefinition(); - - // insert implicit "parent" node, will be removed at end. - // DEFINITION CALL - $parent_name = $definition->info_parent; - array_unshift($tokens, new HTMLPurifier_Token_Start($parent_name)); - $tokens[] = new HTMLPurifier_Token_End($parent_name); - - // setup the context variable 'IsInline', for chameleon processing - // is 'false' when we are not inline, 'true' when it must always - // be inline, and an integer when it is inline for a certain - // branch of the document tree - $is_inline = $definition->info_parent_def->descendants_are_inline; - $context->register('IsInline', $is_inline); - - // setup error collector - $e =& $context->get('ErrorCollector', true); - - //####################################################################// - // Loop initialization - - // stack that contains the indexes of all parents, - // $stack[count($stack)-1] being the current parent - $stack = array(); - - // stack that contains all elements that are excluded - // it is organized by parent elements, similar to $stack, - // but it is only populated when an element with exclusions is - // processed, i.e. there won't be empty exclusions. - $exclude_stack = array(); - - // variable that contains the start token while we are processing - // nodes. This enables error reporting to do its job - $start_token = false; - $context->register('CurrentToken', $start_token); - - //####################################################################// - // Loop - - // iterate through all start nodes. Determining the start node - // is complicated so it has been omitted from the loop construct - for ($i = 0, $size = count($tokens) ; $i < $size; ) { - - //################################################################// - // Gather information on children - - // child token accumulator - $child_tokens = array(); - - // scroll to the end of this node, report number, and collect - // all children - for ($j = $i, $depth = 0; ; $j++) { - if ($tokens[$j] instanceof HTMLPurifier_Token_Start) { - $depth++; - // skip token assignment on first iteration, this is the - // token we currently are on - if ($depth == 1) continue; - } elseif ($tokens[$j] instanceof HTMLPurifier_Token_End) { - $depth--; - // skip token assignment on last iteration, this is the - // end token of the token we're currently on - if ($depth == 0) break; - } - $child_tokens[] = $tokens[$j]; - } - - // $i is index of start token - // $j is index of end token - - $start_token = $tokens[$i]; // to make token available via CurrentToken - - //################################################################// - // Gather information on parent - - // calculate parent information - if ($count = count($stack)) { - $parent_index = $stack[$count-1]; - $parent_name = $tokens[$parent_index]->name; - if ($parent_index == 0) { - $parent_def = $definition->info_parent_def; - } else { - $parent_def = $definition->info[$parent_name]; - } - } else { - // processing as if the parent were the "root" node - // unknown info, it won't be used anyway, in the future, - // we may want to enforce one element only (this is - // necessary for HTML Purifier to clean entire documents - $parent_index = $parent_name = $parent_def = null; - } - - // calculate context - if ($is_inline === false) { - // check if conditions make it inline - if (!empty($parent_def) && $parent_def->descendants_are_inline) { - $is_inline = $count - 1; - } - } else { - // check if we're out of inline - if ($count === $is_inline) { - $is_inline = false; - } - } - - //################################################################// - // Determine whether element is explicitly excluded SGML-style - - // determine whether or not element is excluded by checking all - // parent exclusions. The array should not be very large, two - // elements at most. - $excluded = false; - if (!empty($exclude_stack)) { - foreach ($exclude_stack as $lookup) { - if (isset($lookup[$tokens[$i]->name])) { - $excluded = true; - // no need to continue processing - break; - } - } - } - - //################################################################// - // Perform child validation - - if ($excluded) { - // there is an exclusion, remove the entire node - $result = false; - $excludes = array(); // not used, but good to initialize anyway - } else { - // DEFINITION CALL - if ($i === 0) { - // special processing for the first node - $def = $definition->info_parent_def; - } else { - $def = $definition->info[$tokens[$i]->name]; - - } - - if (!empty($def->child)) { - // have DTD child def validate children - $result = $def->child->validateChildren( - $child_tokens, $config, $context); - } else { - // weird, no child definition, get rid of everything - $result = false; - } - - // determine whether or not this element has any exclusions - $excludes = $def->excludes; - } - - // $result is now a bool or array - - //################################################################// - // Process result by interpreting $result - - if ($result === true || $child_tokens === $result) { - // leave the node as is - - // register start token as a parental node start - $stack[] = $i; - - // register exclusions if there are any - if (!empty($excludes)) $exclude_stack[] = $excludes; - - // move cursor to next possible start node - $i++; - - } elseif($result === false) { - // remove entire node - - if ($e) { - if ($excluded) { - $e->send(E_ERROR, 'Strategy_FixNesting: Node excluded'); - } else { - $e->send(E_ERROR, 'Strategy_FixNesting: Node removed'); - } - } - - // calculate length of inner tokens and current tokens - $length = $j - $i + 1; - - // perform removal - array_splice($tokens, $i, $length); - - // update size - $size -= $length; - - // there is no start token to register, - // current node is now the next possible start node - // unless it turns out that we need to do a double-check - - // this is a rought heuristic that covers 100% of HTML's - // cases and 99% of all other cases. A child definition - // that would be tricked by this would be something like: - // ( | a b c) where it's all or nothing. Fortunately, - // our current implementation claims that that case would - // not allow empty, even if it did - if (!$parent_def->child->allow_empty) { - // we need to do a double-check - $i = $parent_index; - array_pop($stack); - } - - // PROJECTED OPTIMIZATION: Process all children elements before - // reprocessing parent node. - - } else { - // replace node with $result - - // calculate length of inner tokens - $length = $j - $i - 1; - - if ($e) { - if (empty($result) && $length) { - $e->send(E_ERROR, 'Strategy_FixNesting: Node contents removed'); - } else { - $e->send(E_WARNING, 'Strategy_FixNesting: Node reorganized'); - } - } - - // perform replacement - array_splice($tokens, $i + 1, $length, $result); - - // update size - $size -= $length; - $size += count($result); - - // register start token as a parental node start - $stack[] = $i; - - // register exclusions if there are any - if (!empty($excludes)) $exclude_stack[] = $excludes; - - // move cursor to next possible start node - $i++; - - } - - //################################################################// - // Scroll to next start node - - // We assume, at this point, that $i is the index of the token - // that is the first possible new start point for a node. - - // Test if the token indeed is a start tag, if not, move forward - // and test again. - $size = count($tokens); - while ($i < $size and !$tokens[$i] instanceof HTMLPurifier_Token_Start) { - if ($tokens[$i] instanceof HTMLPurifier_Token_End) { - // pop a token index off the stack if we ended a node - array_pop($stack); - // pop an exclusion lookup off exclusion stack if - // we ended node and that node had exclusions - if ($i == 0 || $i == $size - 1) { - // use specialized var if it's the super-parent - $s_excludes = $definition->info_parent_def->excludes; - } else { - $s_excludes = $definition->info[$tokens[$i]->name]->excludes; - } - if ($s_excludes) { - array_pop($exclude_stack); - } - } - $i++; - } - - } - - //####################################################################// - // Post-processing - - // remove implicit parent tokens at the beginning and end - array_shift($tokens); - array_pop($tokens); - - // remove context variables - $context->destroy('IsInline'); - $context->destroy('CurrentToken'); - - //####################################################################// - // Return - - return $tokens; - - } - -} - -// vim: et sw=4 sts=4 |