rework dependency types code

Simplify, change default content depends number to 1,
change interface to make more sense.

11 files changed, 55 insertions, 59 deletions

diff --git a/IkiWiki.pm b/IkiWiki.pm
index 5e5dc739d..c1d07531e 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -29,8 +29,8 @@ our $version='unknown'; # VERSION_AUTOREPLACE done by Makefile, DNE
 our $installdir='/usr'; # INSTALLDIR_AUTOREPLACE done by Makefile, DNE
 
 # Page dependency types.
-our $DEPEND_EXISTS=1;
-our $DEPEND_CONTENT=2;
+our $DEPEND_CONTENT=1;
+our $DEPEND_PRESENCE=2;
 
 # Optimisation.
 use Memoize;
@@ -1540,13 +1540,13 @@ sub loadindex () {
 			if (exists $d->{dependslist}) {
 				# old format
 				$depends{$page}={
-					map { $_ => $DEPEND_CONTENT | $DEPEND_EXISTS }
+					map { $_ => $DEPEND_CONTENT }
 						@{$d->{dependslist}}
 				};
 			}
 			elsif (exists $d->{depends} && ! ref $d->{depends}) {
 				# old format
-				$depends{$page}={$d->{depends} => $DEPEND_CONTENT | $DEPEND_EXISTS};
+				$depends{$page}={$d->{depends} => $DEPEND_CONTENT };
 			}
 			elsif (exists $d->{depends}) {
 				$depends{$page}=$d->{depends};
@@ -1771,16 +1771,23 @@ sub add_depends ($$;@) {
 	my $page=shift;
 	my $pagespec=shift;
 
+	# Is the pagespec a simple page name?
 	my $simple=$pagespec =~ /$config{wiki_file_regexp}/ &&
 		$pagespec !~ /[\s*?()!]/;
 
-	my $deptype=$DEPEND_CONTENT | $DEPEND_EXISTS;
+	my $deptype=$DEPEND_CONTENT;
 	if (@_) {
 		my %params=@_;
-		if (defined $params{content} && $params{content} == 0 &&
-		    ($simple || pagespec_contentless($pagespec))) {
-			$deptype=$deptype & ~$DEPEND_CONTENT;
+		
+		# Is the pagespec limited to terms that will continue
+		# to match pages as long as those pages exist?
+		my $limited=1;
+		while ($limited && $pagespec=~m/(\w+)\([^\)]*\)/g) {
+			$limited = $1 =~ /^(glob|internal|creation_month|creation_day|creation_year|created_before|created_after)$/;
 		}
+
+		$deptype=$deptype & ~$DEPEND_CONTENT & $DEPEND_PRESENCE
+			if $params{presence} && $limited;
 	}
 
 	if ($simple) {
@@ -1976,18 +1983,6 @@ sub pagespec_valid ($) {
 	return ! $@;
 }
 
-sub pagespec_contentless ($) {
-	my $spec=shift;
-
-	while ($spec=~m{
-		(\w+)\([^\)]*\) # only match pagespec functions
-	}igx) {
-		return 0 unless $1=~/^(glob|internal|creation_month|creation_day|creation_year|created_before|created_after)$/;
-	}
-
-	return 1;
-}
-
 sub glob2re ($) {
 	my $re=quotemeta(shift);
 	$re=~s/\\\*/.*/g;
diff --git a/IkiWiki/Plugin/calendar.pm b/IkiWiki/Plugin/calendar.pm
index a5cc20882..a1117992a 100644
--- a/IkiWiki/Plugin/calendar.pm
+++ b/IkiWiki/Plugin/calendar.pm
@@ -105,21 +105,21 @@ sub format_month (@) {
 			linktext => " $monthname ");
 	}
 	add_depends($params{page}, "$archivebase/$year/".sprintf("%02d", $month),
-		content => 0);
+		presence => 1);
 	if (exists $cache{$pagespec}{"$pyear/$pmonth"}) {
 		$purl = htmllink($params{page}, $params{destpage}, 
 			"$archivebase/$pyear/" . sprintf("%02d", $pmonth),
 			linktext => " $pmonthname ");
 	}
 	add_depends($params{page}, "$archivebase/$pyear/".sprintf("%02d", $pmonth),
-		content => 0);
+		presence => 1);
 	if (exists $cache{$pagespec}{"$nyear/$nmonth"}) {
 		$nurl = htmllink($params{page}, $params{destpage}, 
 			"$archivebase/$nyear/" . sprintf("%02d", $nmonth),
 			linktext => " $nmonthname ");
 	}
 	add_depends($params{page}, "$archivebase/$nyear/".sprintf("%02d", $nmonth),
-		content => 0);
+		presence => 1);
 
 	# Start producing the month calendar
 	$calendar=<<EOF;
@@ -212,11 +212,11 @@ EOF
 
 	# Add dependencies to update the calendar whenever pages
 	# matching the pagespec are added or removed.
-	add_depends($params{page}, $params{pages}, content => 0);
+	add_depends($params{page}, $params{pages}, presence => 1);
 	# Explicitly add all currently linked pages as dependencies, so
 	# that if they are removed, the calendar will be sure to be updated.
 	foreach my $p (@list) {
-		add_depends($params{page}, $p, content => 0);
+		add_depends($params{page}, $p, presence => 1);
 	}
 
 	return $calendar;
@@ -249,19 +249,19 @@ sub format_year (@) {
 			"$archivebase/$year",
 			linktext => "$year");
 	}
-	add_depends($params{page}, "$archivebase/$year", content => 0);
+	add_depends($params{page}, "$archivebase/$year", presence => 1);
 	if (exists $cache{$pagespec}{"$pyear"}) {
 		$purl = htmllink($params{page}, $params{destpage}, 
 			"$archivebase/$pyear",
 			linktext => "\&larr;");
 	}
-	add_depends($params{page}, "$archivebase/$pyear", content => 0);
+	add_depends($params{page}, "$archivebase/$pyear", presence => 1);
 	if (exists $cache{$pagespec}{"$nyear"}) {
 		$nurl = htmllink($params{page}, $params{destpage}, 
 			"$archivebase/$nyear",
 			linktext => "\&rarr;");
 	}
-	add_depends($params{page}, "$archivebase/$nyear", content => 0);
+	add_depends($params{page}, "$archivebase/$nyear", presence => 1);
 
 	# Start producing the year calendar
 	$calendar=<<EOF;
@@ -313,7 +313,7 @@ EOF
 		else {
 			$calendar.=qq{\t<td class="$tag">$monthabbr</td>\n};
 		}
-		add_depends($params{page}, "$archivebase/$year/$mtag", content => 0);
+		add_depends($params{page}, "$archivebase/$year/$mtag", presence => 1);
 
 		$calendar.=qq{\t</tr>\n} if ($month % $params{months_per_row} == 0);
 	}
diff --git a/IkiWiki/Plugin/edittemplate.pm b/IkiWiki/Plugin/edittemplate.pm
index 89d450725..2dd1dbe68 100644
--- a/IkiWiki/Plugin/edittemplate.pm
+++ b/IkiWiki/Plugin/edittemplate.pm
@@ -58,7 +58,7 @@ sub preprocess (@) {
 	$pagestate{$params{page}}{edittemplate}{$params{match}}=$link;
 
 	return "" if ($params{silent} && IkiWiki::yesno($params{silent}));
-	add_depends($params{page}, $link, content => 0);
+	add_depends($params{page}, $link, presence => 1);
 	return sprintf(gettext("edittemplate %s registered for %s"),
 		htmllink($params{page}, $params{destpage}, $link),
 	       	$params{match});
diff --git a/IkiWiki/Plugin/listdirectives.pm b/IkiWiki/Plugin/listdirectives.pm
index 96150f986..4023ed7d7 100644
--- a/IkiWiki/Plugin/listdirectives.pm
+++ b/IkiWiki/Plugin/listdirectives.pm
@@ -84,7 +84,7 @@ sub preprocess (@) {
 	foreach my $plugin (@pluginlist) {
 		$result .= '<li class="listdirectives">';
 		my $link=linkpage($config{directive_description_dir}."/".$plugin);
-		add_depends($params{page}, $link, content => 0);
+		add_depends($params{page}, $link, presence => 1);
 		$result .= htmllink($params{page}, $params{destpage}, $link);
 		$result .= '</li>';
 	}
diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
index eef3013a0..9b041a748 100644
--- a/IkiWiki/Plugin/meta.pm
+++ b/IkiWiki/Plugin/meta.pm
@@ -195,7 +195,7 @@ sub preprocess (@) {
 			if (! length $link) {
 				error gettext("redir page not found")
 			}
-			add_depends($page, $link, content => 0);
+			add_depends($page, $link, presence => 1);
 
 			$value=urlto($link, $page);
 			$value.='#'.$redir_anchor if defined $redir_anchor;
diff --git a/IkiWiki/Plugin/pagecount.pm b/IkiWiki/Plugin/pagecount.pm
index 17eda0618..80561350b 100644
--- a/IkiWiki/Plugin/pagecount.pm
+++ b/IkiWiki/Plugin/pagecount.pm
@@ -23,8 +23,8 @@ sub preprocess (@) {
 	$params{pages}="*" unless defined $params{pages};
 	
 	# Needs to update count whenever a page is added or removed, so
-	# register a contentless dependency.
-	add_depends($params{page}, $params{pages}, content => 0);
+	# register a presence dependency.
+	add_depends($params{page}, $params{pages}, presence => 1);
 	
 	my @pages;
 	if ($params{pages} eq "*") {
diff --git a/IkiWiki/Plugin/postsparkline.pm b/IkiWiki/Plugin/postsparkline.pm
index 694d39575..3205958d4 100644
--- a/IkiWiki/Plugin/postsparkline.pm
+++ b/IkiWiki/Plugin/postsparkline.pm
@@ -48,7 +48,7 @@ sub preprocess (@) {
 		error gettext("unknown formula");
 	}
 
-	add_depends($params{page}, $params{pages}, content => 0);
+	add_depends($params{page}, $params{pages}, presence => 1);
 
 	my @list=sort { $params{timehash}->{$b} <=> $params{timehash}->{$a} } 
 		pagespec_match_list(
diff --git a/IkiWiki/Plugin/progress.pm b/IkiWiki/Plugin/progress.pm
index 3b664f4cb..26c537a84 100644
--- a/IkiWiki/Plugin/progress.pm
+++ b/IkiWiki/Plugin/progress.pm
@@ -36,8 +36,8 @@ sub preprocess (@) {
 		$fill.="%";
 	}
 	elsif (defined $params{totalpages} and defined $params{donepages}) {
-		add_depends($params{page}, $params{totalpages}, content => 0);
-		add_depends($params{page}, $params{donepages}, content => 0);
+		add_depends($params{page}, $params{totalpages}, presence => 1);
+		add_depends($params{page}, $params{donepages}, presence => 1);
 
 		my @pages=keys %pagesources;
 		my $totalcount=0;
diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index 3fc750925..cf0c3fe08 100644
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -473,13 +473,11 @@ sub refresh () {
 	
 				if (exists $depends_simple{$p}) {
 					foreach my $d (keys %{$depends_simple{$p}}) {
-						if ($depends_simple{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
-							if (exists $lc_exists_changed{$d}) {
-								$reason = $d;
-								last;
-							}
-						}
-						elsif (exists $lc_changed{$d}) {
+						if (($depends_simple{$p}{$d} & $IkiWiki::DEPEND_CONTENT &&
+						     exists $lc_changed{$d})
+						    ||
+						    ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_PRESENCE &&
+						     exists $lc_exists_changed{$d})) {
 							$reason = $d;
 							last;
 						}
@@ -492,22 +490,22 @@ sub refresh () {
 						next if $@ || ! defined $sub;
 	
 						my @candidates;
-						if ($depends{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
-							@candidates=@exists_changed;
-						}
-						else {
+						if ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_CONTENT) {
 							@candidates=@changed;
 						}
+						elsif ($depends{$p}{$d} & $IkiWiki::DEPEND_PRESENCE) {
+							@candidates=@exists_changed;
+						}
 						# only consider internal files
 						# if the page explicitly depends
 						# on such files
 						if ($d =~ /internal\(/) {
-							if ($depends{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
-								push @candidates, @internal;
-							}
-							else {
+							if ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_CONTENT) {
 								push @candidates, @internal, @internal_change;
 							}
+							elsif ($depends{$p}{$d} & $IkiWiki::DEPEND_PRESENCE) {
+								push @candidates, @internal;
+							}
 						}
 	
 						foreach my $file (@candidates) {
diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index c244c1f2f..73db6f12a 100644
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -613,12 +613,15 @@ generating a link to a page.
 
 Makes the specified page depend on the specified [[ikiwiki/PageSpec]].
 
-Additional named parameters can be passed, to indicate what type of
-dependency this is.
-
-Currently, only a "content" parameter is specified. If set to 0, the
-dependency does not involve the content of pages matching the PageSpec, but
-only their existence.
+By default, dependencies are full content dependencies, meaning that the
+page will be updated whenever anything matching the PageSpec is modified.
+This default can be overridden by additional named parameters, which can be
+used to indicate weaker types of dependencies:
+
+* `presence` if set to true, only the presence of a matching page triggers
+  the dependency.
+* `links` if set to true, any change in the text of links on a matching page
+  triggers the dependency
 
 #### `pagespec_match($$;@)`
 
diff --git a/ikiwiki-transition b/ikiwiki-transition
index c50a748e8..1bebb1176 100755
--- a/ikiwiki-transition
+++ b/ikiwiki-transition
@@ -299,7 +299,7 @@ sub oldloadindex {
 			$pagemtime{$page}=$items{mtime}[0];
 			$oldlinks{$page}=[@{$items{link}}];
 			$links{$page}=[@{$items{link}}];
-			$depends{$page}={ $items{depends}[0] => $IkiWiki::DEPEND_CONTENT | $IkiWiki::DEPEND_EXISTS } if exists $items{depends};
+			$depends{$page}={ $items{depends}[0] => $IkiWiki::DEPEND_CONTENT } if exists $items{depends};
 			$destsources{$_}=$page foreach @{$items{dest}};
 			$renderedfiles{$page}=[@{$items{dest}}];
 			$pagecase{lc $page}=$page;