[[!template id=plugin name=comments author="[[Simon_McVittie|smcv]]"]]
[[!tag type/useful]]

This plugin adds "blog-style" comments. The intention is that on a non-wiki site
(like a blog) you can lock all pages for admin-only access, then allow otherwise
unprivileged (or perhaps even anonymous) users to comment on posts.

When using this plugin, you should also enable [[htmlscrubber]] and either [[htmltidy]]
or [[htmlbalance]]. Directives are filtered out by default, to avoid commenters slowing
down the wiki by causing time-consuming processing. As long as the recommended plugins
are enabled, comment authorship should hopefully be unforgeable by CGI users.

The plugin adds a new [[ikiwiki/PageSpec]] match type, `postcomment`, for use
with `anonok_pagespec` from the [[plugins/anonok]] plugin or `locked_pages` from
the [[plugins/lockedit]] plugin. Typical usage would be something like:

    locked_pages => "!postcomment(*)"

to allow non-admin users to comment on pages, but not edit anything. You can also do

    anonok_pages => "postcomment(*)"

to allow anonymous comments (the IP address will be used as the "author").

There are some global options for the setup file:

* `comments_shown_pagespec`: pages where comments will be displayed inline, e.g. `blog/*`
  or `*/discussion`.
* `comments_open_pagespec`: pages where new comments can be posted, e.g.
  `blog/* and created_after(close_old_comments)` or `*/discussion`
* `comments_pagename`: if this is e.g. `comment_` (the default), then comments on the
  [[sandbox]] will be called something like `sandbox/comment_12`
* `comments_allowdirectives`: if true (default false), comments may contain IkiWiki
  directives
* `comments_commit`: if true (default true), comments will be committed to the version
  control system
* `comments_allowauthor`: if true (default false), anonymous commenters may specify a
  name for themselves, and the \[[!meta author]] and \[[!meta authorurl]] directives
  will not be overridden by the comments plugin

Templates that will display comments (by default that means `comments_display.tmpl`)
can use the following additional `<TMPL_VAR>`s:

* `COMMENTUSER`: the authenticated/verified user name, or undefined if the user was not signed in
* `COMMENTIP`: the remote IP address, or undefined if not known (this is not currently recorded
  for users who are signed in, who are assumed to be vaguely accountable)
* `COMMENTAUTHOR`: a "prettier" version of the authenticated/verified user name (e.g. OpenIDs are
  formatted the same way as in [[RecentChanges]]), or the result of localizing "Anonymous" if the
  user was not signed in
* `COMMENTAUTHORURL`: if the user was signed in with an OpenID, that URL; if the user was signed
  in with some other username, a CGI URL that redirects to their user page (if any)

This plugin also adds a `\[[!comment]]` directive which is used when storing comments. This
directive shouldn't be used on pages that are edited in the usual way.

This plugin aims to close the [[todo]] item "[[todo/supporting_comments_via_disussion_pages]]",
and is currently available from [[smcv]]'s git repository on git.pseudorandom.co.uk (it's the
`comments-rebase1` branch). A demo wiki with the plugin enabled is running at
<http://www.pseudorandom.co.uk/2008/ikiwiki/demo/>; the
[sandbox page](http://www.pseudorandom.co.uk/2008/ikiwiki/demo/sandbox/#comments) has some
examples of comments.

Known issues:

* Needs code review
* The access control via postcomment() is rather strange (see [[discussion]] for more details)
* There is some common code cargo-culted from other plugins (notably inline and editpage) which
  should probably be shared
* Joey doesn't think it should necessarily use internal pages (see [[discussion]])
* `\[[!comment]]` should perhaps be `\[[!_comment]], or a special filter/htmlize hook rather
  than being a directive at all

> I haven't done a detailed code review, but I will say I'm pleased you
> avoided re-implementing inline! --[[Joey]]

Fixed issues:

* Joey didn't think the `\[[!comments]]` directive was appropriate; comments now appear
  on pages selected with a [[ikiwiki/pagespec]]
* Joey thought that raw HTML should always be allowed; it now is
* tbm wanted anonymous people to be able to enter their name and possibly email
  address; a name and website can now be supplied
* There is now an indication of who you're signed in as
* Each comment is now one big \[[!comment]] directive invocation, avoiding previous
  issues with unambiguous and un-spoofable metadata