mirror of
https://github.com/vichan-devel/vichan.git
synced 2024-12-02 11:08:34 +01:00
51 lines
2.3 KiB
Plaintext
51 lines
2.3 KiB
Plaintext
|
|
Handling Content Model Changes
|
|
|
|
|
|
1. Context
|
|
|
|
The distinction between Transitional and Strict document types is somewhat
|
|
of an anomaly in the lineage of XHTML document types (following 1.0, no
|
|
doctypes do not have flavors: instead, modularization is used to let
|
|
document authors vary their elements). This transition is usually quite
|
|
straight-forward, as W3C usually deprecates attributes or elements, which
|
|
are quite easily handled using tag and attribute transforms.
|
|
|
|
However, for two elements, <blockquote>, <body> and <address>, W3C elected
|
|
to also change the content model. <blockquote> and <body> originally
|
|
accepted both inline and block elements, but in the strict doctype they
|
|
only allow block elements. With <address>, the situation is inverted:
|
|
<p> tags were now forbidden from appearing within this tag.
|
|
|
|
|
|
2. Current situation
|
|
|
|
Currently, HTML Purifier treats <blockquote> specially during Tidy mode
|
|
using a custom ChildDef class StrictBlockquote. StrictBlockquote
|
|
operates similarly to Required, except that when it encounters an inline
|
|
element, it will wrap it in a block tag (as specified by
|
|
%HTML.BlockWrapper, the default is <p>). The naming suggests it can
|
|
only be used for <blockquote>s, although it may be possible to
|
|
genericize it to work on other cases of this nature (this would be of
|
|
little practical application, as no other element in XHTML 1.1 or earlier
|
|
has a block-only content model).
|
|
|
|
Tidy currently contains no custom, lenient implementation for <address>.
|
|
If one were to be written, it would likely operate on the principle that,
|
|
when a <p> tag were to be encountered, it would be replaced with a
|
|
leading and trailing <br /> tag (the contents of <p>, being inline, are
|
|
not an issue). There is no prior work with this sort of operation.
|
|
|
|
|
|
3. Outside applicability
|
|
|
|
There are a number of other elements that contain restrictive content
|
|
models, such as <ul> or <span> (the latter is restrictive in that it
|
|
does not allow block elements). In the former case, an errant node
|
|
is eliminated completely, in the latter case, the text of the node
|
|
would is preserved (as the parent node does allow PCDATA). Custom
|
|
content model implementations probably are not the best way of handling
|
|
these cases, instead, node bubbling should be implemented instead.
|
|
|
|
vim: et sw=4 sts=4
|