0
0
mirror of https://github.com/ezyang/htmlpurifier.git synced 2024-11-10 15:48:42 +00:00
htmlpurifier/library/HTMLPurifier/ConfigSchema/schema/AutoFormat.RemoveEmpty.txt
Edward Z. Yang 700d5bcbfc Implement %AutoFormat.RemoveEmpty, end to start ref, and injector rewind.
Injector rewind: Injectors can now use the method rewind() in order to move
the input index backwards, so that they can reprocess tokens (other injectors
are not affected by a rewind). This functionality was necessary to implement
nested node removals in %AutoFormat.RemoveEmpty.

End to start ref: To facilitate rewinding, HTMLPurifier_Token_End now
maintains a reference called $start to the starting token for their node.

%AutoFormat.RemoveEmpty removes empty nodes. Lots of people have requested
it, so here is a partially effective implementation. Because it is implemented
as an Injector, it's not possible for it to handle newly introduced empty
nodes by later validators, specifically auto-closing and child validation.
The Injector is only meant to be used on HTML-ish languages.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
2008-06-27 16:09:14 -04:00

45 lines
1.6 KiB
Plaintext

AutoFormat.RemoveEmpty
TYPE: bool
VERSION: 3.1.2
DEFAULT: false
--DESCRIPTION--
<p>
When enabled, HTML Purifier will attempt to remove empty elements that
contribute no semantic information to the document. The following types
of nodes will be removed:
</p>
<ul><li>
Tags with no attributes and no content, and that are not empty
elements (remove <code>&lt;a&gt;&lt;/a&gt;</code> but not
<code>&lt;br /&gt;</code>), and
</li>
<li>
Tags with no content, except for:<ul>
<li>The <code>colgroup</code> element, or</li>
<li>
Elements with the <code>id</code> or <code>name</code> attribute,
when those attributes are permitted on those elements.
</li>
</ul></li>
</ul>
<p>
Please be very careful when using this functionality; while it may not
seem that empty elements contain useful information, they can alter the
layout of a document given appropriate styling. This directive is most
useful when you are processing machine-generated HTML, please avoid using
it on regular user HTML.
</p>
<p>
Elements that contain only whitespace will be treated as empty. Non-breaking
spaces, however, do not count as whitespace.
</p>
<p>
This algorithm is not perfect; you may still notice some empty tags,
particularly if a node had elements, but those elements were later removed
because they were not permitted in that context, or tags that, after
being auto-closed by another tag, where empty. This is for safety reasons
to prevent clever code from breaking validation. The general rule of thumb:
if a tag looked empty on the way end, it will get removed; if HTML Purifier
made it empty, it will stay.
</p>