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htmlpurifier/library/HTMLPurifier/ChildDef/Empty.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

39 lines
866 B
PHP

<?php
/**
* Definition that disallows all elements.
* @warning validateChildren() in this class is actually never called, because
* empty elements are corrected in HTMLPurifier_Strategy_MakeWellFormed
* before child definitions are parsed in earnest by
* HTMLPurifier_Strategy_FixNesting.
*/
class HTMLPurifier_ChildDef_Empty extends HTMLPurifier_ChildDef
{
/**
* @type bool
*/
public $allow_empty = true;
/**
* @type string
*/
public $type = 'empty';
public function __construct()
{
}
/**
* @param HTMLPurifier_Node[] $children
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return array
*/
public function validateChildren($children, $config, $context)
{
return array();
}
}
// vim: et sw=4 sts=4