Since some preprocessor directives insert raw HTML, it would be good to specify, per-format, how to pass HTML so that it goes through the format OK. With Markdown we cross our fingers; with reST we use the "raw" directive.

I added an extra named parameter to the htmlize hook, which feels sort of wrong, since none of the other hooks take parameters. Let me know what you think. --Ethan

Seems fairly reasonable, actually. Shouldn't the $type come from $page instead of $destpage though? Only other obvious change is to make the escape parameter optional, and only call it if set. --Joey

I couldn't figure out what to make it from, but thinking it through, yeah, it should be $page. Revised patch follows. --Ethan

I've updated the patch some more, but I think it's incomplete. ikiwiki emits raw html when expanding WikiLinks too, and it would need to escape those. Assuming that escaping html embedded in the middle of a sentence works.. --Joey

Revised again. I get around this by making another hook, htmlescapelink, which is called to generate links in whatever language. In addition, it doesn't (can't?) generate spans, and it doesn't handle inlineable image links. If these were desired, the approach to take would probably be to use substitution definitions, which would require generating two bits of code for each link/html snippet, and putting one at the end of the paragraph (or maybe the document?). To specify that (for example) Discussion links are meant to be HTML and not rst or whatever, I added a "genhtml" parameter to htmllink. It seems to work -- see http://ikidev.betacantrips.com/blah.html for an example. --Ethan

Alternative solution

Here is a patch largely inspired from the one below, which is up to date and written with multiple output formats in mind. "htmlize" hooks are generalized to "convert" ones, which can be registered for any pair of filename extensions.

Preprocessor directives are allowed to return the content to be inserted as a hash, in any format they want, provided they provide htmlize hooks for it. Pseudo filename extensions (such as "_link") can also be introduced, which aren't used as real extensions but provide useful intermediate types.

--JeremieKoenig

Wow, this is in many ways a beautiful patch. I did notice one problem, if a link is converted to rst and then from there to a hyperlink, the styling info usially added to such a link is lost. I wonder if it would be better to lose _link stuff and just create link html that is fed into the rst,html converter. Other advantage to doing that is that link creation has a rather complex interface, with selflink, attrs, url, and content parameters.

--Joey

Thanks for the compliment. I must confess that I'm not too familiar with rst. I am using this todo item somewhat as a pretext to get the conversion stuff in, which I need to implement some other stuff. As a result I was less careful with the rst plugin than with the rest of the patch. I just updated the patch to fix some other problems which I found with more testing, and document the current limitations.

Rst cannot embed raw html in the middle of a paragraph, which is why "_link" was necessary. Rst links are themselves tricky and can't be made to work inside of words without knowledge about the context. Both problems could be fixed by inserting marks instead of the html/link, which would be replaced at a later stage (htmlize, format), somewhat similiar to the way the toc plugin works. When I get more time I will try to fix the remaining glitches this way.

Also, I think it would be useful if ikiwiki had an option to export the preprocessed source. This way you can use docutils to convert your rst documents to other formats. Raw html would be loosed in such a process (both with directives and marks), which is another argument for "_link" and other intermediate forms. I think I can come up with a way for rst's convert_link to be used only for export purposes, though.

--JeremieKoenig

Another problem with this approach is when there is some html (say a table), that contains a wikilink. If the link is left up to the markup lamguage to handle, it will never convert it to a link, since the table will be processed as a chunk of raw html. --Joey

Updated patch

I've created an updated patch against the current revision. No real functionality changes, except for a small test script, one minor bugfix (put a "join" around a scalar-context "map" in convert_link), and some wrangling to get it merged properly; I thought it might be helpful for anyone else who wants to work on the code.

(With that out of the way, I think I'm going to take a stab at Jeremie's plan to use marks which would be replaced post-htmlization. I've also got an eye towards multiple output formats.)

--Ryan Koppenhaver

Original patch

Index: debian/changelog
===================================================================
--- debian/changelog    (revision 3197)
+++ debian/changelog    (working copy)
@@ -24,6 +24,9 @@
     than just a suggests, since OpenID is enabled by default.
   * Fix a bug that caused link(foo) to succeed if page foo did not exist.
   * Fix tags to page names that contain special characters.
+  * Based on a patch by Ethan, add a new htmlescape hook, that is called
+    when a preprocssor directive emits inline html. The rst plugin uses this
+    hook to support inlined raw html.
 
   [ Josh Triplett ]
   * Use pngcrush and optipng on all PNG files.
Index: IkiWiki/Render.pm
===================================================================
--- IkiWiki/Render.pm   (revision 3197)
+++ IkiWiki/Render.pm   (working copy)
@@ -96,7 +96,7 @@
        if ($page !~ /.*\/\Q$discussionlink\E$/ &&
           (length $config{cgiurl} ||
            exists $links{$page."/".$discussionlink})) {
-           $template->param(discussionlink => htmllink($page, $page, gettext("Discussion"), noimageinline => 1, forcesubpage => 1));
+           $template->param(discussionlink => htmllink($page, $page, gettext("Discussion"), noimageinline => 1, forcesubpage => 1, genhtml => 1));
            $actions++;
        }
    }
Index: IkiWiki/Plugin/rst.pm
===================================================================
--- IkiWiki/Plugin/rst.pm   (revision 3197)
+++ IkiWiki/Plugin/rst.pm   (working copy)
@@ -30,15 +30,36 @@
 html = publish_string(stdin.read(), writer_name='html', 
        settings_overrides = { 'halt_level': 6, 
                               'file_insertion_enabled': 0,
-                              'raw_enabled': 0 }
+                              'raw_enabled': 1 }
 );
 print html[html.find('')+6:html.find('')].strip();
 ";
 
 sub import {
    hook(type => "htmlize", id => "rst", call => \&htmlize);
+   hook(type => "htmlescape", id => "rst", call => \&htmlescape);
+   hook(type => "htmlescapelink", id => "rst", call => \&htmlescapelink);
 }
 
+sub htmlescapelink ($$;@) {
+   my $url = shift;
+   my $text = shift;
+   my %params = @_;
+
+   if ($params{broken}){
+       return "`? <$url>`_\ $text";
+   }
+   else {
+       return "`$text <$url>`_";
+   }
+}
+
+sub htmlescape ($) {
+   my $html=shift;
+   $html=~s/^/  /mg;
+   return ".. raw:: html\n\n".$html;
+}
+
 sub htmlize (@) {
    my %params=@_;
    my $content=$params{content};
Index: doc/plugins/write.mdwn
===================================================================
--- doc/plugins/write.mdwn  (revision 3197)
+++ doc/plugins/write.mdwn  (working copy)
@@ -121,6 +121,26 @@
 The function is passed named parameters: "page" and "content" and should
 return the htmlized content.
 
+### htmlescape
+
+   hook(type => "htmlescape", id => "ext", call => \&htmlescape);
+
+Some markup languages do not allow raw html to be mixed in with the markup
+language, and need it to be escaped in some way. This hook is a companion
+to the htmlize hook, and is called when ikiwiki detects that a preprocessor
+directive is inserting raw html. It is passed the chunk of html in
+question, and should return the escaped chunk.
+
+### htmlescapelink
+
+   hook(type => "htmlescapelink", id => "ext", call => \&htmlescapelink);
+
+Some markup languages have special syntax to link to other pages. This hook
+is a companion to the htmlize and htmlescape hooks, and it is called when a
+link is inserted. It is passed the target of the link and the text of the 
+link, and an optional named parameter "broken" if a broken link is being
+generated. It should return the correctly-formatted link.
+
 ### pagetemplate
 
    hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
@@ -355,6 +375,7 @@
 * forcesubpage  - set to force a link to a subpage
 * linktext - set to force the link text to something
 * anchor - set to make the link include an anchor
+* genhtml - set to generate HTML and not escape for correct format
 
 #### `readfile($;$)`
 
Index: doc/plugins/rst.mdwn
===================================================================
--- doc/plugins/rst.mdwn    (revision 3197)
+++ doc/plugins/rst.mdwn    (working copy)
@@ -10,10 +10,8 @@
 Note that this plugin does not interoperate very well with the rest of
 ikiwiki. Limitations include:
 
-* reStructuredText does not allow raw html to be inserted into
-  documents, but ikiwiki does so in many cases, including
-  WikiLinks and many
-  Directives.
+* Some bits of ikiwiki may still assume that markdown is used or embed html
+  in ways that break reStructuredText. (Report bugs if you find any.)
 * It's slow; it forks a copy of python for each page. While there is a
   perl version of the reStructuredText processor, it is not being kept in
   sync with the standard version, so is not used.
Index: IkiWiki.pm
===================================================================
--- IkiWiki.pm  (revision 3197)
+++ IkiWiki.pm  (working copy)
@@ -469,6 +469,10 @@
    my $page=shift; # the page that will contain the link (different for inline)
    my $link=shift;
    my %opts=@_;
+   # we are processing $lpage and so we need to format things in accordance
+   # with the formatting language of $lpage. inline generates HTML so links
+   # will be escaped seperately.
+   my $type=pagetype($pagesources{$lpage});
 
    my $bestlink;
    if (! $opts{forcesubpage}) {
@@ -494,12 +498,17 @@
    }
    if (! grep { $_ eq $bestlink } map { @{$_} } values %renderedfiles) {
        return $linktext unless length $config{cgiurl};
-       return " "create",
-               page => pagetitle(lc($link), 1),
-               from => $lpage
-           ).
+       my $url = cgiurl(
+                do => "create",
+                page => pagetitle(lc($link), 1),
+                from => $lpage
+               );
+
+       if ($hooks{htmlescapelink}{$type} && ! $opts{genhtml}){
+           return $hooks{htmlescapelink}{$type}{call}->($url, $linktext,
+                                  broken => 1);
+       }
+       return "?$linktext"
    }
    
@@ -514,6 +523,9 @@
        $bestlink.="#".$opts{anchor};
    }
 
+   if ($hooks{htmlescapelink}{$type} && !$opts{genhtml}) {
+     return $hooks{htmlescapelink}{$type}{call}->($bestlink, $linktext);
+   }
    return "$linktext";
 }
 
@@ -628,6 +640,14 @@
                preview => $preprocess_preview,
            );
            $preprocessing{$page}--;
+
+           # Handle escaping html if the htmlizer needs it.
+           if ($ret =~ /[<>]/ && $pagesources{$page}) {
+               my $type=pagetype($pagesources{$page});
+               if ($hooks{htmlescape}{$type}) {
+                   return $hooks{htmlescape}{$type}{call}->($ret);
+               }
+           }
            return $ret;
        }
        else {