TODO List

= KEY ====================
    # Flagship
    - Regular
    ? Maybe I'll Do It
==========================

If no interest is expressed for a feature that may required a considerable
amount of effort to implement, it may get endlessly delayed. Do not be
afraid to cast your vote for the next feature to be implemented!

IMPORTANT
 - Get everything into configuration objects (filters, I'm looking at you)
 - Factor demo.php into a set of Printer classes, and then create a stub
   file for users here (inside the actual HTML Purifier library)
 - Test HTMLPurifier.auto.php, HTMLPurifier.includes.php, and combinations
   of the two.
 - Document new ConfigSchema setup and format; dev-includes.txt is a base
   but we need it in HTML
 - Document new methods of including the library
 - We should do a release candidate, because of the major changes
 - Move utility classes for ConfigSchema into HTML Purifier itself: they're
   that important
 - Factor generate-schema-cache.php into a class, so that the maintenance script
   is as small as possible
 - Document which scripts need to be called when a change is made
 - Semi-automated smoketests using PHPT style files

3.1 release [Error'ed]
 # Error logging for filtering/cleanup procedures
 - XSS-attempt detection

3.2 release [Do What I Mean, Not What I Say]
 # Additional support for poorly written HTML
    - Microsoft Word HTML cleaning (i.e. MsoNormal, but research essential!)
    - Friendly strict handling of <address> (block -> <br>)
 - Remove redundant tags, ex. <u><u>Underlined</u></u>. Implementation notes:
    1. Analyzing which tags to remove duplicants
    2. Ensure attributes are merged into the parent tag
    3. Extend the tag exclusion system to specify whether or not the
    contents should be dropped or not (currently, there's code that could do
    something like this if it didn't drop the inner text too.)
 - Remove <span> tags that don't do anything (no attributes)
 - Remove empty inline tags<i></i>
 - Append something to duplicate IDs so they're still usable (impl. note: the
   dupe detector would also need to detect the suffix as well)
 - Externalize inline CSS to promote clean HTML

3.3 release [It's All About Trust] (floating)
 # Implement untrusted, dangerous elements/attributes
 # Implement IDREF support (harder than it seems, since you cannot have
   IDREFs to non-existent IDs)
 # Frameset XHTML 1.0 and HTML 4.01 doctypes

4.0 release [Beyond HTML]
 # Legit token based CSS parsing (will require revamping almost every
   AttrDef class). Probably will use CSSTidy class
 # More control over allowed CSS properties (maybe modularize it in the
   same fashion!)
 - Standardize token armor for all areas of processing
 - Convert RTL/LTR override characters to <bdo> tags, or vice versa on demand.
   Also, enable disabling of directionality
 - Table of Contents generation (XHTML Compiler might be reusable)

5.0 release [To XML and Beyond]
 - Extended HTML capabilities based on namespacing and tag transforms (COMPLEX)
    - Hooks for adding custom processors to custom namespaced tags and
      attributes, offer default implementation
    - Lots of documentation and samples

Ongoing
 - More refactoring to take advantage of PHP5's facilities 
 - Lots of profiling, make it faster!
 - Plugins for major CMSes (COMPLEX)
    - phpBB
    - more! (look for ones that use WYSIWYGs)
 - Complete basic smoketests

AutoFormat
 - Smileys
 - Syntax highlighting with <pre> and possibly <?php
 - Look at http://drupal.org/project/Modules/category/63 for ideas

Unknown release (on a scratch-an-itch basis)
 # CHMOD install script for PEAR installs
 ? Have 'lang' attribute be checked against official lists, achieved by
   encoding all characters that have string entity equivalents
 - Abstract ChildDef_BlockQuote to work with all elements that only
   allow blocks in them, required or optional
 - Reorganize Unit Tests
 - Advanced URI filtering schemes (see docs/proposal-new-directives.txt)
 - Implement lenient <ruby> child validation
 - Explain how to use HTML Purifier in non-PHP languages / create
   a simple command line stub (or complicated?)
 - Fixes for Firefox's inability to handle COL alignment props (Bug 915)
 - Automatically add non-breaking spaces to empty table cells when
   empty-cells:show is applied to have compatibility with Internet Explorer
 - Distinguish between default settings and explicitly set settings, so
   configurations can be merged
 - Nested configuration namespaces
 - Allow scoped="scoped" attribute in <style> tags; may be troublesome
   because regular CSS has no way of uniquely identifying nodes, so we'd
   have to generate IDs

Requested

Wontfix
 - Non-lossy smart alternate character encoding transformations (unless
   patch provided)
 - Pretty-printing HTML: users can use Tidy on the output on entire page
 - Native content compression, whitespace stripping (don't rely on Tidy, make
   sure we don't remove from <pre> or related tags): use gzip if this is
   really important