I've got a wiki where editing requires [[plugins/httpauth]] (with
`cgiauthurl` working nicely). I now want to let the general public
edit Discussion subpages, so I enabled [[plugins/anonok]] and set
`anonok_pagespec` to `'*/Discussion'`, but HTTP auth is still being
required for those.

(Actually, what I'll really want to do is probably [[plugins/lockedit]]
and a whitelist of OpenIDs in `locked_pages`...)

--[[schmonz]]

> The only way I can see to support this combination is for httpauth with
> cgiauthurl to work more like other actual login types. Which would mean
> that on editing a page that needs authentication, ikiwiki would redirect
> them to the Signin page, which would then have a link they could follow
> to bounce through the cgiauthurl and actually sign in. This would be
> significantly different than the regular httpauth process, in which the
> user signs in in passing. --[[Joey]]

>> My primary userbase has grown accustomed to the seamlessness of
>> httpauth with SPNEGO, so I'd rather not reintroduce a seam into
>> their web-editing experience in order to let relatively few outsiders
>> edit relatively few pages. When is the decision made about whether
>> the current page can be edited by the current user (if any)? What
>> if there were a way to require particular auth plugins for particular
>> PageSpecs? --[[schmonz]]

>>> The decision about whether a user can edit a page is made by plugins
>>> such as signinedit and lockedit, that also use canedit hooks to redirect
>>> the user to a signin page if necessary.
>>> 
>>> A tweak on my earlier suggestion would be to have httpauth notice when the 
>>> Signin page is being built and immediatly redirect to the cgiauthurl
>>> before the page can be shown to the user. This would, though, not play
>>> well with other authentication methods like openid, since the user
>>> would never see the Signin form. --[[Joey]]

>>>> Would I be able to do what I want with a local plugin that
>>>> abuses canedit (and auth) to reach in and call the appropriate
>>>> plugin's auth method -- e.g., if the page matches */Discussion,
>>>> call `openid:auth()`, else `httpauth:auth()`? --[[schmonz]]

>>>>> That seems it would be
>>>>> annoying for httpauth users (who were not currently authed),
>>>>> as they would then see the openid signin form when going to edit a
>>>>> Discussion page.
>>>>> --[[Joey]]

>>>>>> I finally see the problem, I think. When you initially
>>>>>> suggested "a link they could follow to bounce through the
>>>>>> cgiauthurl", presumably this could _be_ the Edit link for
>>>>>> non-Discussion pages, so that the typical case of an httpauth
>>>>>> user editing an editable-only-by-httpauth page doesn't visibly
>>>>>> change. And then the Edit link for Discussion subpages could do
>>>>>> as you suggest, adding one click for the httpauth user, who won't
>>>>>> often need to edit those subpages. --[[schmonz]]

>> On reflection, I've stopped being bothered by the
>> redirect-to-signin-page approach. (It only needs to happen once per
>> browser session, anyway.) Can we try that? --[[schmonz]]

Here is an attempt. With this httpauth will only redirect to the
`cgiauth_url` when a page is edited, and it will defer to other plugins
like anonok first. I have not tested this. --[[Joey]] 

<pre>
diff --git a/IkiWiki/Plugin/httpauth.pm b/IkiWiki/Plugin/httpauth.pm
index 127c321..a18f8ca 100644
--- a/IkiWiki/Plugin/httpauth.pm
+++ b/IkiWiki/Plugin/httpauth.pm
@@ -9,6 +9,8 @@ use IkiWiki 3.00;
 sub import {
 	hook(type => "getsetup", id => "httpauth", call => \&getsetup);
 	hook(type => "auth", id => "httpauth", call => \&auth);
+	hook(type => "canedit", id => "httpauth", call => \&canedit,
+		last => 1);
 }
 
 sub getsetup () {
@@ -33,9 +35,21 @@ sub auth ($$) {
 	if (defined $cgi->remote_user()) {
 		$session->param("name", $cgi->remote_user());
 	}
-	elsif (defined $config{cgiauthurl}) {
-		IkiWiki::redirect($cgi, $config{cgiauthurl}.'?'.$cgi->query_string());
-		exit;
+}
+
+sub canedit ($$$) {
+	my $page=shift;
+	my $cgi=shift;
+	my $session=shift;
+
+	if (! defined $cgi->remote_user() && defined $config{cgiauthurl}) {
+		return sub {
+			IkiWiki::redirect($cgi, $config{cgiauthurl}.'?'.$cgi->query_string());
+			exit;
+		};
+	}
+	else {
+		return undef;
 	}
 }
 
</pre>

> With `anonok` enabled, this works for anonymous editing of an
> existing Discussion page. auth is still needed to create one. --[[schmonz]]

>> Refreshed above patch to fix that. --[[Joey]] 

>> Remaining issue: This patch will work with anonok, but not openid or
>> passwordauth, both of which want to display a login page at the same
>> time that httpauth is redirecting to the cgiauthurl. As mentioned above,
>> the only way to deal with that would be to add a link to the signin page
>> that does the httpauth signin. --[[Joey]] 

>>> That's dealt with in final version. [[done]] --[[Joey]]