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htmlpurifier/library/HTMLPurifier/ChildDef/Chameleon.php
Edward Z. Yang 0767bbc12d Rewrite FixNesting implementation to be tree-based.
This mega-patch rips out the FixNesting implementation and the related
ChildDef components.  The primary algorithmic change is to convert from
use of tokens to tree nodes, which are far more amenable to the style
of processing that FixNesting uses.  Additionally, FixNesting has been
changed to go bottom-up rather than top-down, in order to avoid needing
to implement backtracking.

This patch simplifies a good deal of the relevant logic, since we no
longer need to continually recalculate the nesting structure when
processing things.  However, the conversion to the alternate format
incurs some overhead, so for small inputs these changes are not a win.
One possibility to greatly reduce the constant factors here is to switch
to entirely using libxml's representation, and never serializing tokens;
this would require one to rewrite injectors, however.

The iterative post-order traversal in FixNesting is a bit subtle, but
we have essentially reified the stack and continuations.

We've removed support for %Core.EscapeInvalidChildren.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
2013-10-20 22:37:01 -07:00

68 lines
1.9 KiB
PHP

<?php
/**
* Definition that uses different definitions depending on context.
*
* The del and ins tags are notable because they allow different types of
* elements depending on whether or not they're in a block or inline context.
* Chameleon allows this behavior to happen by using two different
* definitions depending on context. While this somewhat generalized,
* it is specifically intended for those two tags.
*/
class HTMLPurifier_ChildDef_Chameleon extends HTMLPurifier_ChildDef
{
/**
* Instance of the definition object to use when inline. Usually stricter.
* @type HTMLPurifier_ChildDef_Optional
*/
public $inline;
/**
* Instance of the definition object to use when block.
* @type HTMLPurifier_ChildDef_Optional
*/
public $block;
/**
* @type string
*/
public $type = 'chameleon';
/**
* @param array $inline List of elements to allow when inline.
* @param array $block List of elements to allow when block.
*/
public function __construct($inline, $block)
{
$this->inline = new HTMLPurifier_ChildDef_Optional($inline);
$this->block = new HTMLPurifier_ChildDef_Optional($block);
$this->elements = $this->block->elements;
}
/**
* @param HTMLPurifier_Node[] $children
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return bool
*/
public function validateChildren($children, $config, $context)
{
if ($context->get('IsInline') === false) {
return $this->block->validateChildren(
$children,
$config,
$context
);
} else {
return $this->inline->validateChildren(
$children,
$config,
$context
);
}
}
}
// vim: et sw=4 sts=4