Syndication autodiscovery for comment feeds
A standard \[[!inline]] directive adds links to the autogenerated syndication feeds using link tags in the header:
<link rel="alternate" type="application/rss+xml" title="$title" href="$page.atom" />
<link rel="alternate" type="application/atom+xml" title="$title" href="$page.atom" />
These links aren't added to my pages that include comments even though comments generate syndication feeds. How can I configure the comments plugin to add these links to the header? (These links are required for user-agent autodiscovery of syndication feeds.) --[[anderbubble]]
Moderating comments from the CLI
How do you do this, without using the UI in the Preferences?
Please put this info on the page. Many thanks --[[Kai Hendry]]
Why internal pages? (unresolved)
Comments are saved as internal pages, so they can never be edited through the CGI,
only by direct committers.
So, why do it this way, instead of using regular wiki pages in a
namespace, such as $page/comments/*? Then you could use [[plugins/lockedit]] to
limit editing of comments in more powerful ways. --[[Joey]]
Er... I suppose so. I'd assumed that these pages ought to only exist as inlines
rather than as individual pages (same reasoning as aggregated posts), though.
lockedit is actually somewhat insufficient, since check_canedit()
doesn't distinguish between creation and editing; I'd have to continue to use
some sort of odd hack to allow creation but not editing.
I also can't think of any circumstance where you'd want a user other than
admins (~= git committers) and possibly the commenter (who we can't check for
at the moment anyway, I don't think?) to be able to edit comments - I think
user expectations for something that looks like ordinary blog comments are
likely to include "others can't put words into my mouth".
My other objection to using a namespace is that I'm not particularly happy about
plugins consuming arbitrary pieces of the wiki namespace - /discussion is bad
enough already. Indeed, this very page would accidentally get matched by rules
aiming to control comment-posting... :-) --[[smcv]]
Thinking about it, perhaps one way to address this would be to have the suffix
(e.g. whether commenting on Sandbox creates sandbox/comment1 or sandbox/c1 or
what) be configurable by the wiki admin, in the same way that recentchanges has
recentchangespage => 'recentchanges'? I'd like to see fewer hard-coded page
names in general, really - it seems odd to me that shortcuts and smileys
hard-code the name of the page to look at. Perhaps I could add
discussionpage => 'discussion' too? --[[smcv]]
(I've now implemented this in my branch. --[[smcv]])
The best reason to keep the pages internal seems to me to be that you
don't want the overhead of every comment spawning its own wiki page. --[[Joey]]
Formats (resolved)
The plugin now allows multiple comment formats while still using internal
pages; each comment is saved as a page containing one \[[!comment]] directive,
which has a superset of the functionality of [[ikiwiki/directives/format]].
Access control (unresolved?)
By the way, I think that who can post comments should be controllable by
the existing plugins opendiscussion, anonok, signinedit, and lockedit. Allowing
posting comments w/o any login, while a nice capability, can lead to
spam problems. So, use check_canedit as at least a first-level check?
--[[Joey]]
This plugin already uses check_canedit, but that function doesn't have a concept
of different actions. The hack I use is that when a user comments on, say, sandbox,
I call check_canedit for the pseudo-page "sandbox[postcomment]". The
special postcomment(glob) [[ikiwiki/pagespec]] returns true if the page ends with
"[postcomment]" and the part before (e.g. sandbox) matches the glob. So, you can
have postcomment(blog/*) or something. (Perhaps instead of taking a glob, postcomment
should take a pagespec, so you can have postcomment(link(tags/commentable))?)
This is why anonok_pagespec => 'postcomment(*)' and locked_pages => '!postcomment(*)'
are necessary to allow anonymous and logged-in editing (respectively).
I changed that to move the flag out of the page name, and into a variable that the match_postcomment
function checks for. Other ugliness still applies. :-) --[[Joey]]
This is ugly - one alternative would be to add check_permission() that takes a
page and a verb (create, edit, rename, remove and maybe comment are the ones I
can think of so far), use that, and port the plugins you mentioned to use that
API too. This plugin could either call check_can("$page/comment1", 'create') or
call check_can($page, 'comment').
One odd effect of the code structure I've used is that we check for the ability to
create the page before we actually know what page name we're going to use - when
posting the comment I just increment a number until I reach an unused one - so
either the code needs restructuring, or the permission check for 'create' would
always be for 'comment1' and never 'comment123'. --[[smcv]]
Now resolved, in fact --[[smcv]]
Another possibility is to just check for permission to edit (e.g.) sandbox/comment1.
However, this makes the "comments can only be created, not edited" feature completely
reliant on the fact that internal pages can't be edited. Perhaps there should be a
editable_pages pagespec, defaulting to '*'? --[[smcv]]
comments directive vs global setting (resolved?)
When comments have been enabled generally, you still need to mark which pages
can have comments, by including the \[[!comments]] directive in them. By default,
this directive expands to a "post a comment" link plus an \[[!inline]] with
the comments. [This requirement has now been removed --[[smcv]]]
I don't like this, because it's hard to explain to someone why they have
to insert this into every post to their blog. Seems that the model used
for discussion pages could work -- if comments are enabled, automatically
add the comment posting form and comments to the end of each page.
--[[Joey]]
I don't think I'd want comments on every page (particularly, not the
front page). Perhaps a pagespec in the setup file, where the default is "*"?
Then control freaks like me could use "link(tags/comments)" and tag pages
as allowing comments.
Yes, I think a pagespec is the way to go. --[[Joey]]
Implemented --[[smcv]]
The model used for discussion pages does require patching the existing
page template, which I was trying to avoid - I'm not convinced that having
every possible feature hard-coded there really scales (and obviously it's
rather annoying while this plugin is on a branch). --[[smcv]]
Using the template would allow customising the html around the comments
which seems like a good thing? --[[Joey]]
The [[!comments]] directive is already template-friendly - it expands to
the contents of the template comments_embed.tmpl, possibly with the
result of an [[!inline]] appended. I should change comments_embed.tmpl
so it uses a template variable INLINE for the inline result rather than
having the perl code concatenate it, which would allow a bit more
customization (whether the "post" link was before or after the inline).
Even if you want comments in page.tmpl, keeping the separate comments_embed.tmpl
and having a COMMENTS variable in page.tmpl might be the way forward,
since the smaller each templates is, the easier it will be for users
to maintain a patched set of templates. (I think so, anyway, based on what happens
with dpkg prompts in Debian packages with monolithic vs split
conffiles.) --[[smcv]]
I've switched my branch to use page.tmpl instead; see what you think? --[[smcv]]
Raw HTML (resolved?)
Raw HTML was not initially allowed by default (this was configurable).
I'm not sure that raw html should be a problem, as long as the
htmlsanitizer and htmlbalanced plugins are enabled. I can see filtering
out directives, as a special case. --[[Joey]]
Right, if I sanitize each post individually, with htmlscrubber and either htmltidy
or htmlbalance turned on, then there should be no way the user can forge a comment;
I was initially wary of allowing meta directives, but I think those are OK, as long
as the comment template puts the [[!meta author]] at the end. Disallowing
directives is more a way to avoid commenters causing expensive processing than
anything else, at this point.
I've rebased the plugin on master, made it sanitize individual posts' content
and removed the option to disallow raw HTML. Sanitizing individual posts before
they've been htmlized required me to preserve whitespace in the htmlbalance
plugin, so I did that. Alternatively, we could htmlize immediately and always
save out raw HTML? --[[smcv]]
There might be some use cases for other directives, such as img, in
comments.
I don't know if meta is "safe" (ie, guaranteed to be inexpensive and not
allow users to do annoying things) or if it will continue to be in the
future. Hard to predict really, all that can be said with certainty is
all directives will contine to be inexpensive and safe enough that it's
sensible to allow users to (ab)use them on open wikis.
--[[Joey]]
I have a test ikiwiki setup somewhere to investigate adopting the comments
plugin. It is setup with no auth enabled and I got hammered with a spam attack
over the last weekend (predictably). What surprised me was the scale of the
attack: ikiwiki eventually triggered OOM and brought the box down. When I got
it back up, I checked out a copy of the underlying git repository, and it
measured 280M in size after being packed. Of that, about 300K was data prior
to the spam attack, so the rest was entirely spam text, compressed via git's
efficient delta compression.
I had two thoughts about possible improvements to the comments plugin in the
wake of this:
-
comment pagination - there is a hard-to-define upper limit on the number
of comments that can be appended to a wiki page whilst the page remains
legible. It would be useful if comments could be paginated into sub-pages.
-
crude flood control - asides from spam attacks (and I am aware of
[[plugins/blogspam]]), people can crap flood or just aggressively flame
repeatedly. An interesting prevention measure might be to not let an IP
post more than 3 sequential comments to a page, or to the site, without
at least one other comment being interleaved. I say 3 rather than 2 since
correction follow-ups are common.
-- [[Jon]]
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