mirror of
https://github.com/ezyang/htmlpurifier.git
synced 2024-11-08 14:58:42 +00:00
a43a2730bc
git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@320 48356398-32a2-884e-a903-53898d9a118a
68 lines
2.7 KiB
Plaintext
68 lines
2.7 KiB
Plaintext
|
|
Filter Levels
|
|
When one size *does not* fit all
|
|
|
|
The more I think about it, the less sense it makes for maintaining one huge
|
|
monolithic HTMLDefinition class. There's simply so much variation that
|
|
could go into this definition: the set of HTML good for blog entries is
|
|
definitely too large for HTML that would be allowed in blog comments. Going
|
|
from Transitional to Strict requires changes to the definition.
|
|
|
|
However, allowing users to specify their own whitelists was an idea I
|
|
rejected from the start. Simply put, the typical programmer is too lazy
|
|
to actually go through the trouble of investigating which tags, attributes
|
|
and properties to allow. HTMLDefinition makes a big part of what HTMLPurifier
|
|
is.
|
|
|
|
The idea, then, is to setup fundamentally different set of definitions, which
|
|
can further be customized using simpler configuration options.
|
|
|
|
Here are some fuzzy levels you could set:
|
|
|
|
1. Comments - Wordpress recommends a, abbr, acronym, b, blockquote, cite,
|
|
code, em, i, strike, strong; however, you could get away with only a, b and
|
|
i; also having p and pre tags would be helpful.
|
|
2. Pages - As permissive as possible without allowing XSS. No protection
|
|
against bad design sense, unfortunantely. Suitable for wiki and page
|
|
environments.
|
|
3. Lint - Accept everything in the spec, a Tidy wannabe.
|
|
|
|
I've also decomposed tags into risk levels. An asterisk indicates that no one
|
|
really uses that tag, tilde indicates it's deprecated.
|
|
|
|
1 - blockquote, code, em, i, p, tt / strong, sub, sup
|
|
1* - abbr, acronym, bdo, cite, dfn, kbd, q, samp
|
|
2 - b, br, del, div, pre, span / ins, s, strike ~ u
|
|
3 - h2, h3, h4, h5, h6 ~ center
|
|
4 - h1, big ~ font
|
|
5 - a
|
|
7 - area, map
|
|
|
|
Lists - dd, dl, dt, li, ol, ul ~ menu, dir
|
|
Tables - caption, table, td, th, tr / col, colgroup, tbody, tfoot, thead
|
|
Forms - fieldset, form, input, lable, legend, optgroup, option, select, textarea
|
|
XSS - noscript, object, script ~ applet
|
|
|
|
Meta - base, basefont, body, head, html, link, meta, style, title
|
|
Frames - frame, frameset, iframe
|
|
|
|
And tag specific notes:
|
|
|
|
a - general problems involving linkspam
|
|
b - too much bold is bad, typographically speaking bold is discouraged
|
|
br - often misused
|
|
center - CSS, usually no legit use
|
|
del - only useful in editing context
|
|
div - little meaning in certain contexts i.e. blog comment
|
|
h1 - usually no legit use, as header is already set by application
|
|
h* - not needed in blog comments
|
|
hr - usually not necessary in blog comments
|
|
img - could be extremely undesirable if linking to external pics
|
|
pre - could use formatting, only useful in code contexts
|
|
q - very little support
|
|
s - transform into span with styling or del?
|
|
small - technically presentational
|
|
span - depends on attribute allowances
|
|
sub, sup - specialized
|
|
u - little legit use, prefer class with text-decoration
|