I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so on several wikis. However, as far as I can tell, ikiwiki has no functionality which can represent dependencies between bugs and allow pagespecs to select based on dependencies. For instance, I can't write a pagespec which selects all bugs with no dependencies on bugs not marked as done. --[[JoshTriplett]]
I started having a think about this. I'm going to start with the idea that expanding
the pagespec syntax is the way to attack this. It seems that any pagespec that is going
to represent "all bugs with no dependencies on bugs not marked as done" is going to
need some way to represent "bugs not marked as done" as a collection of pages, and
then represent "bugs which do not link to pages in the previous collection".
One way to do this would be to introduce variables into the pagespec, along with
universal and/or existential [[!wikipedia Quantification]]. That looks quite complex.
I thought about this briefly, and got about that far.. glad you got
further. :-) --[[Joey]]
Another option would be go with a more functional syntax. The concept here would
be to allow a pagespec to appear in a 'pagespec function' anywhere a page can. e.g.
I could pass a pagespec to link() and that would return true if there is a link to any
page matching the pagespec. This makes the variables and existential quantification
implicit. It would allow the example requested above:
bugs/* and !*/Discussion and !link(bugs/* and !*/Discussion and !link(done))
Unfortunately, this is also going to make the pagespec parsing more complex because
we now need to parse nested sets of parentheses to know when the nested pagespec
ends, and that isn't a regular language (we can't use regular expression matching for
easy parsing).
Also, it may cause ambiguities with page names that contain parens
(though some such ambigutities already exist with the pagespec syntax).
One simplification of that would be to introduce some pagespec [[shortcuts]]. We could
then allow pagespec functions to take either pages, or named pagespec shortcuts. The
pagespec shortcuts would just be listed on a special page, like current [[shortcuts]].
(It would probably be a good idea to require that shortcuts on that page can only refer
to named pagespecs higher up that page than themselves. That would stop some
looping issues...) These shortcuts would be used as follows: when trying to match
a page (without globs) you look to see if the page exists. If it does then you have a
match. If it doesn't, then you look to see if a similarly named pagespec shortcut
exists. If it does, then you check that pagespec recursively to see if you have a match.
The ordering requirement on named pagespecs stops infinite recursion.
Does that seem like a reasonable first approach?
-- [[Will]]
Having a separate page for the shortcuts feels unwieldly.. perhaps
instead the shortcut could be defined earlier in the scope of the same
pagespec that uses it?
Example: define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)
That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok.
Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between
a definition and a page name, the definition would win.
That was my initial thought too :), but when implementing it I decided that requiring the ~ made things easier. I'll probably require the ~ for the first pass at least.
So, equivilant example: define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)
Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the
number of pages in the wiki is not avoided. Probably need to add DOS prevention.
--[[Joey]]
If you memoize the outcomes of the named pagespecs you can make in O(N.X), no?
-- [[Will]]
One quick further thought. All the above discussion assumes that 'dependency' is the
same as 'links to', which is not really true. For example, you'd like to be able to say
"This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency.
Without having different types of links, I don't see how this would be possible.
-- [[Will]]
Okie - I've had a quick attempt at this. Initial patch attached. This one doesn't quite work.
And there is still a lot of debugging stuff in there.
At the moment I've added a new preprocessor plugin, definepagespec, which is like
shortcut for pagespecs. To reference a named pagespec, use ~ like this:
[ [!definepagespec name="bugs" spec="bugs/* and !*/Discussion"]]
[ [!definepagespec name="openbugs" spec="~bugs and !link(done)"]]
[ [!definepagespec name="readybugs" spec="~openbugs and !link(~openbugs)"]]
At the moment the problem is in match_link() when we're trying to find a sub-page that
matches the appropriate page spec. There is no good list of pages available to iterate over.
foreach my $nextpage (keys %IkiWiki::pagesources)
does not give me a good list of pages. I found the same thing when I was working on
this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]].
I'm not sure why iterating over %pagesources wouldn't work here, it's the same method
used by anything that needs to match a pagespec against all pages..? --[[Joey]]
My uchecked hypothesis is that %pagesources is created after the refresh hook.
I've also been concerned about how globally defined pagespec shortcuts would interact with
the page dependancy system. Your idea of internally defined shortcuts should fix that. -- [[Will]]
Immediately below is a patch for IkiWiki.pm. Below that is a new plugin definepagespec
which behaves like shortcut for pagespecs.
diff --git a/IkiWiki.pm b/IkiWiki.pm
index e476521..1d2d48c 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -14,7 +14,7 @@ use open qw{:utf8 :std};
use vars qw{%config %links %oldlinks %pagemtime %pagectime %pagecase
%pagestate %renderedfiles %oldrenderedfiles %pagesources
%destsources %depends %hooks %forcerebuild $gettext_obj
use Exporter q{import};
our @EXPORT = qw(hook debug error template htmlpage add_depends pagespec_match
@@ -22,7 +22,7 @@ our @EXPORT = qw(hook debug error template htmlpage add_depends pagespec_match
displaytime will_render gettext urlto targetpage
add_underlay
%config %links %pagestate %renderedfiles
our $VERSION = 2.00; # plugin interface version, next is ikiwiki version
our $version='unknown'; # VERSION_AUTOREPLACE done by Makefile, DNE
my $installdir=''; # INSTALLDIR_AUTOREPLACE done by Makefile, DNE
@@ -1271,7 +1271,7 @@ sub loadindex () { #{{{
%oldrenderedfiles=%pagectime=();
if (! $config{rebuild}) {
%pagesources=%pagemtime=%oldlinks=%links=%depends=
-
%destsources=%renderedfiles=%pagecase=%pagestate=%named_pagespec=();
}
my $in;
if (! open ($in, "<", "$config{wikistatedir}/indexdb")) {
@@ -1729,6 +1729,8 @@ sub match_glob ($$;@) { #{{{
my $from=exists $params{location} ? $params{location} : '';
-
print "Matching glob $glob \n";
-
relative matching
if ($glob =~ m!^./!) {
$from=~s#/?[^/]+$##;
@@ -1736,6 +1738,18 @@ sub match_glob ($$;@) { #{{{
$glob="$from/$glob" if length $from;
}
-
if (substr($glob, 0, 1) eq '~') {
-
my $specname = substr($glob, 1);
-
print "Checking for pagespec named $specname \n";
-
if (exists $IkiWiki::named_pagespec{$specname}) {
-
my $spec = $IkiWiki::named_pagespec{$specname};
-
return IkiWiki::pagespec_match($page, $spec, %params);
-
} else {
-
print "Couldn't find pagespec\n";
-
return IkiWiki::FailReason->new("Page spec $specname referenced on page $page does not exist");
-
}
-
}
-
my $regexp=IkiWiki::glob2re($glob);
if ($page=~/^$regexp$/i) {
if (! IkiWiki::isinternal($page) || $params{internal}) {
@@ -1756,11 +1770,36 @@ sub match_internal ($$;@) { #{{{
sub match_link ($$;@) { #{{{
my $page=shift;
-
my $fulllink=shift;
-
my $link=lc($fulllink);
my %params=@_;
-
print "Matching link $fulllink \n";
-
my $from=exists $params{location} ? $params{location} : '';
-
if (substr($fulllink, 0, 1) eq '~') {
-
my $specname = substr($fulllink, 1);
-
print "Checking link pagespec $specname \n";
-
if (exists $IkiWiki::named_pagespec{$specname}) {
-
my $spec = $IkiWiki::named_pagespec{$specname};
-
print "Checking all pages against $spec\n";
-
foreach my $nextpage (keys %IkiWiki::pagesources) {
-
print "Checking $nextpage against $spec\n";
-
if (pagespec_match($nextpage, $spec, %params) && IkiWiki::PageSpec::match_link($page, $nextpage, %params)) {
-
return IkiWiki::SuccessReason->new("$page links to page $nextpage matching $link")
-
}
-
}
-
return IkiWiki::FailReason->new("$page has no links to any pages that match $spec");
-
} else {
-
print "Pagespec $specname not found\n";
-
return IkiWiki::FailReason->new("$page cannot link to nonexistent spec name $specname");
-
}
-
}
-
relative matching
if ($link =~ m!^.! && defined $from) {
$from=~s#/?[^/]+$##;
#!/usr/bin/perl
package IkiWiki::Plugin::definepagespec;
use warnings;
use strict;
use IkiWiki 2.00;
sub import { #{{{
hook(type => "getsetup", id => "definepagespec", call => &getsetup);
hook(type => "refresh", id => "definepagespec", call => &refresh);
hook(type => "preprocess", id => "definepagespec", call => &preprocess);
} #}}}
sub getsetup () { #{{{
return
plugin => {
safe => 1,
rebuild => undef,
},
} #}}}
sub refresh () { #{{{
# Preprocess the shortcuts page to get all the available shortcuts
# defined before other pages are rendered.
my $srcfile=srcfile("pagespecs.mdwn", 1);
if (! defined $srcfile) {
error(gettext("definepagespec plugin will not work without a pagespecs.mdwn"));
}
IkiWiki::preprocess("pagespecs", "pagespecs", readfile($srcfile));
} # }}}
sub preprocess (@) { #{{{
my %params=@_;
if (! defined $params{name} || ! defined $params{spec}) {
error gettext("missing name or spec parameter");
}
$IkiWiki::named_pagespec{$params{name}} = $params{spec};
#translators: This is used to display what shortcuts are defined.
#translators: First parameter is the name of the shortcut, the second
#translators: is an URL.
return sprintf(gettext("pagespec %s refers to <i>%s</i>"), $params{name}, $params{spec});
} # }}}
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