* Make pagespec_match on failure return a value that is false, but in a

  scalar context, evaluates to a reason why the match failed.
* Add testpagespec plugin, which might be useful to see why a pagespec isn't
  matching something.

9 files changed, 108 insertions, 33 deletions

diff --git a/IkiWiki.pm b/IkiWiki.pm
index 7c910a53d..88d6d442b 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -998,9 +998,23 @@ sub pagespec_match ($$;@) { #{{{
 		unshift @params, "location";
 	}
 
-	return eval pagespec_translate($spec);
+	my $ret=eval pagespec_translate($spec);
+	return IkiWiki::FailReason->new("syntax error") if $@;
+	return $ret;
 } #}}}
 
+package IkiWiki::FailReason;
+
+use overload (
+	'""' => sub { return ${$_[0]} },
+	'0+' => sub { return 0 },
+	fallback => 1,
+);
+
+sub new {
+	bless \$_[1], $_[0];
+}
+
 package IkiWiki::PageSpec;
 
 sub match_glob ($$;@) { #{{{
@@ -1022,7 +1036,12 @@ sub match_glob ($$;@) { #{{{
 	$glob=~s/\\\*/.*/g;
 	$glob=~s/\\\?/./g;
 
-	return $page=~/^$glob$/i;
+	if ($page=~/^$glob$/i) {
+		return 1
+	}
+	else {
+		return IkiWiki::FailReason->new("$glob does not match $page");
+	}
 } #}}}
 
 sub match_link ($$;@) { #{{{
@@ -1040,13 +1059,13 @@ sub match_link ($$;@) { #{{{
 	}
 
 	my $links = $IkiWiki::links{$page} or return undef;
-	return 0 unless @$links;
+	return IkiWiki::FailReason->new("$page has no links") unless @$links;
 	my $bestlink = IkiWiki::bestlink($from, $link);
-	return 0 unless length $bestlink;
+	return IkiWiki::FailReason->new("no such link") unless length $bestlink;
 	foreach my $p (@$links) {
 		return 1 if $bestlink eq IkiWiki::bestlink($page, $p);
 	}
-	return 0;
+	return IkiWiki::FailReason->new("$page does not link to $link");
 } #}}}
 
 sub match_backlink ($$;@) { #{{{
@@ -1061,7 +1080,7 @@ sub match_created_before ($$;@) { #{{{
 		return $IkiWiki::pagectime{$page} < $IkiWiki::pagectime{$testpage};
 	}
 	else {
-		return 0;
+		return IkiWiki::FailReason->new("$page not created before $testpage");
 	}
 } #}}}
 
@@ -1073,20 +1092,23 @@ sub match_created_after ($$;@) { #{{{
 		return $IkiWiki::pagectime{$page} > $IkiWiki::pagectime{$testpage};
 	}
 	else {
-		return 0;
+		return IkiWiki::FailReason->new("$page not created after $testpage");
 	}
 } #}}}
 
 sub match_creation_day ($$;@) { #{{{
-	return ((gmtime($IkiWiki::pagectime{shift()}))[3] == shift);
+	return 1 if ((gmtime($IkiWiki::pagectime{shift()}))[3] == shift);
+	return IkiWiki::FailReason->new("creation_day did not match");
 } #}}}
 
 sub match_creation_month ($$;@) { #{{{
-	return ((gmtime($IkiWiki::pagectime{shift()}))[4] + 1 == shift);
+	return 1 if ((gmtime($IkiWiki::pagectime{shift()}))[4] + 1 == shift);
+	return IkiWiki::FailReason->new("creation_month did not match");
 } #}}}
 
 sub match_creation_year ($$;@) { #{{{
-	return ((gmtime($IkiWiki::pagectime{shift()}))[5] + 1900 == shift);
+	return 1 if ((gmtime($IkiWiki::pagectime{shift()}))[5] + 1900 == shift);
+	return IkiWiki::FailReason->new("creation_year did not match");
 } #}}}
 
 sub match_user ($$;@) { #{{{
@@ -1094,8 +1116,9 @@ sub match_user ($$;@) { #{{{
 	my $user=shift;
 	my %params=@_;
 
-	return unless exists $params{user};
-	return $user eq $params{user};
+	return IkiWiki::FailReason->new("cannot match user") unless exists $params{user};
+	return 1 if $user eq $params{user};
+	return IkiWiki::FailReason->new("user is not $user");
 } #}}}
 
 1
diff --git a/IkiWiki/Plugin/conditional.pm b/IkiWiki/Plugin/conditional.pm
index 29223ace2..58e2b04b9 100644
--- a/IkiWiki/Plugin/conditional.pm
+++ b/IkiWiki/Plugin/conditional.pm
@@ -62,7 +62,8 @@ sub match_enabled ($$;@) { #{{{
 	my $plugin=shift;
 	
 	# test if the plugin is enabled
-	return UNIVERSAL::can("IkiWiki::Plugin::".$plugin, "import");
+	return 1 if UNIVERSAL::can("IkiWiki::Plugin::".$plugin, "import");
+	return IkiWiki::FailReason->new("$plugin is not enabled");
 } #}}}
 
 sub match_sourcepage ($$;@) { #{{{
@@ -70,8 +71,9 @@ sub match_sourcepage ($$;@) { #{{{
 	my $glob=shift;
 	my %params=@_;
 
-	return unless exists $params{sourcepage};
-	return match_glob($params{sourcepage}, $glob, @_);
+	return IkiWiki::FailReason->new("cannot match sourcepage") unless exists $params{sourcepage};
+	return 1 if match_glob($params{sourcepage}, $glob, @_);
+	return IkiWiki::FailReason->new("sourcepage does not match $glob");
 } #}}}
 
 sub match_destpage ($$;@) { #{{{
@@ -79,8 +81,9 @@ sub match_destpage ($$;@) { #{{{
 	my $glob=shift;
 	my %params=@_;
 	
-	return unless exists $params{destpage};
-	return match_glob($params{destpage}, $glob, @_);
+	return IkiWiki::FailReason->new("cannot match destpage") unless exists $params{destpage};
+	return 1 if match_glob($params{destpage}, $glob, @_);
+	return IkiWiki::FailReason->new("destpage does not match $glob");
 } #}}}
 
 sub match_included ($$;$) { #{{{
@@ -88,8 +91,9 @@ sub match_included ($$;$) { #{{{
 	shift;
 	my %params=@_;
 
-	return unless exists $params{sourcepage} && exists $params{destpage};
-	return $params{sourcepage} ne $params{destpage};
+	return IkiWiki::FailReason->new("cannot match included") unless exists $params{sourcepage} && exists $params{destpage};
+	return 1 if $params{sourcepage} ne $params{destpage};
+	return IkiWiki::FailReason->new("page $params{sourcepage} is not included");
 } #}}}
 
 1
diff --git a/IkiWiki/Plugin/testpagespec.pm b/IkiWiki/Plugin/testpagespec.pm
new file mode 100644
index 000000000..56dc03cef
--- /dev/null
+++ b/IkiWiki/Plugin/testpagespec.pm
@@ -0,0 +1,23 @@
+#!/usr/bin/perl
+package IkiWiki::Plugin::testpagespec;
+
+use warnings;
+use strict;
+use IkiWiki 2.00;
+
+sub import { #{{{
+	hook(type => "preprocess", id => "testpagespec", call => \&preprocess);
+} # }}}
+
+sub preprocess (@) { #{{{
+	my %params=@_;
+	
+	add_depends($params{page}, $params{pagespec});
+	
+	my $ret=pagespec_match($params{match}, $params{pagespec}, 
+			location => $params{page});
+	return $ret if ! $ret;
+	return "the pagespec matches";
+} # }}}
+
+1
diff --git a/debian/changelog b/debian/changelog
index 7f6157e89..ee3792892 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -30,8 +30,12 @@ ikiwiki (1.51) UNRELEASED; urgency=low
   * Plugin interface version increased to 2.00 since I don't anticipate any
     more interface changes before 2.0.
   * Updated Gujarati translation from Kartik Mistry. Closes: #421198
+  * Make pagespec_match on failure return a value that is false, but in a
+    scalar context, evaluates to a reason why the match failed.
+  * Add testpagespec plugin, which might be useful to see why a pagespec isn't
+    matching something.
 
- -- Joey Hess <joeyh@debian.org>  Fri, 27 Apr 2007 01:30:34 -0400
+ -- Joey Hess <joeyh@debian.org>  Fri, 27 Apr 2007 03:41:52 -0400
 
 ikiwiki (1.50) unstable; urgency=low
 
diff --git a/doc/plugins/testpagespec.mdwn b/doc/plugins/testpagespec.mdwn
new file mode 100644
index 000000000..28e5ba7a7
--- /dev/null
+++ b/doc/plugins/testpagespec.mdwn
@@ -0,0 +1,12 @@
+[[template id=plugin name=testpagespec author="[[Joey]]"]]
+[[tag type/useful]]
+
+This plugin allows testing a [[PageSpec]] to see if it matches a page, and
+if not, why it fails to match.
+
+Example use:
+
+	\[[testpagespec pagespec="foopage and barpage" match="foopage"]]
+
+This will print out something like "barpage does not match foopage",
+highlighting which part of the [[PageSpec]] is causing the match to fail.
diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index d9f25641d..ef9d412e5 100644
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -328,6 +328,10 @@ The most often used is "location", which specifies the location the
 PageSpec should match against. If not passed, relative PageSpecs will match
 relative to the top of the wiki.
 
+If the PageSpec fails to match, it may return a IkiWiki::FailReason object,
+which evaluates to false in a boolean context, but in a string context,
+evaulates to the reason the PageSpec failed to match.
+
 #### `bestlink($$)`
 
 Given a page and the text of a link on the page, determine which
@@ -448,4 +452,5 @@ IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is
 how it will be accessed in a [[PageSpec]]. The function will be passed
 two parameters: The name of the page being matched, and the thing to match
 against. It may also be passed additional, named parameters. It should return
-true if the page matches.
+true if the match succeeds, and either false or a IkiWiki::FailReason object
+if the match fails.
diff --git a/po/gu.po b/po/gu.po
index 5fa46b687..9a26e9bd6 100644
--- a/po/gu.po
+++ b/po/gu.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: ikiwiki-gu\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2007-04-23 14:43-0400\n"
+"POT-Creation-Date: 2007-04-27 03:55-0400\n"
 "PO-Revision-Date: 2007-01-11 16:05+0530\n"
 "Last-Translator: Kartik Mistry <kartik.mistry@gmail.com>\n"
 "Language-Team: Gujarati <team@utkarsh.org>\n"
@@ -101,8 +101,8 @@ msgid "feed not found"
 msgstr "ફીડ મળ્યું નહી"
 
 #: ../IkiWiki/Plugin/aggregate.pm:278
-#, perl-format
-msgid "invalid UTF-8 stripped from feed"
+#, fuzzy, perl-format
+msgid "(invalid UTF-8 stripped from feed)"
 msgstr "ફીડમાંથી અયોગ્ય રીતે UTF-8 નીકાળેલ છે"
 
 #: ../IkiWiki/Plugin/aggregate.pm:283
@@ -118,7 +118,7 @@ msgstr "નવું પાનું %s બનાવે છે"
 msgid "There are no broken links!"
 msgstr "અહીં કોઇ તૂટેલ કડી નથી!"
 
-#: ../IkiWiki/Plugin/conditional.pm:20
+#: ../IkiWiki/Plugin/conditional.pm:17
 msgid "\"test\" and \"then\" parameters are required"
 msgstr "\"test\" અને \"then\" વિકલ્પો જરૂરી છે"
 
@@ -396,23 +396,23 @@ msgstr "ખરાબ પહોળાઇ કિંમત"
 msgid "failed to run php"
 msgstr "php ચલાવવામાં નિષ્ફળ"
 
-#: ../IkiWiki/Plugin/table.pm:22
+#: ../IkiWiki/Plugin/table.pm:21
 msgid "cannot find file"
 msgstr "ફાઇલ મળી શકી નહી"
 
-#: ../IkiWiki/Plugin/table.pm:45
+#: ../IkiWiki/Plugin/table.pm:44
 msgid "unknown data format"
 msgstr "અજાણ્યો માહિતી પ્રકાર"
 
-#: ../IkiWiki/Plugin/table.pm:53
+#: ../IkiWiki/Plugin/table.pm:52
 msgid "empty data"
 msgstr "ખાલી માહિતી"
 
-#: ../IkiWiki/Plugin/table.pm:73
+#: ../IkiWiki/Plugin/table.pm:72
 msgid "Direct data download"
 msgstr "સીધી માહિતી ડાઉનલોડ"
 
-#: ../IkiWiki/Plugin/table.pm:106
+#: ../IkiWiki/Plugin/table.pm:105
 #, perl-format
 msgid "parse fail at line %d: %s"
 msgstr "ઉકેલવાનું લીટી %d પર નિષ્ફળ: %s"
@@ -512,7 +512,7 @@ msgstr "સંપૂર્ણ"
 #. translators: A list of one or more pages that were changed,
 #. translators: And the name of the user making the change.
 #. translators: This is used as the subject of a commit email.
-#: ../IkiWiki/UserInfo.pm:146
+#: ../IkiWiki/UserInfo.pm:145
 #, perl-format
 msgid "update of %s's %s by %s"
 msgstr "%s નો સુધારો %s નાં %s વડે"
diff --git a/po/ikiwiki.pot b/po/ikiwiki.pot
index 64af1d2a9..aaac2ef04 100644
--- a/po/ikiwiki.pot
+++ b/po/ikiwiki.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2007-04-26 22:52-0400\n"
+"POT-Creation-Date: 2007-04-27 03:55-0400\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
diff --git a/t/pagespec_match.t b/t/pagespec_match.t
index eac2395ed..f0cadcdc7 100755
--- a/t/pagespec_match.t
+++ b/t/pagespec_match.t
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 use warnings;
 use strict;
-use Test::More tests => 49;
+use Test::More tests => 51;
 
 BEGIN { use_ok("IkiWiki"); }
 
@@ -67,6 +67,10 @@ ok(! pagespec_match("foo", "no_such_function(foo)"), "foo");
 ok(pagespec_match("foo", "foo and user(bar)", user => "bar"), "user");
 ok(! pagespec_match("foo", "foo and user(bar)", user => "baz"), "user fail");
 
+my $ret=pagespec_match("foo", "(invalid");
+ok(! $ret, "syntax error");
+ok($ret eq "syntax error", "error message");
+
 # old style globlists
 ok(pagespec_match("foo", "foo bar"), "simple list");
 ok(pagespec_match("bar", "foo bar"), "simple list 2");