remove: implemented a new canremove hook; use it in the po plugin

Signed-off-by: intrigeri <intrigeri@boum.org>

IkiWiki/Plugin/po.pm

@@ -39,6 +39,7 @@ sub import {
 	hook(type => "rename", id => "po", call => \&renamepages);
 	hook(type => "delete", id => "po", call => \&mydelete);
 	hook(type => "change", id => "po", call => \&change);
+	hook(type => "canremove", id => "po", call => \&canremove);
 	hook(type => "editcontent", id => "po", call => \&editcontent);
 
 	$origsubs{'bestlink'}=\&IkiWiki::bestlink;
@@ -406,6 +407,16 @@ sub change(@) {
 	}
 }
 
+sub canremove ($$$) {
+	my ($page, $cgi, $session) = (shift, shift, shift);
+
+	if (istranslation($page)) {
+		return gettext("Can not remove a translation. Removing the master page,".
+			       "though, removes its translations as well.");
+	}
+	return undef;
+}
+
 # As we're previewing or saving a page, the content may have
 # changed, so tell the next filter() invocation it must not be lazy.
 sub editcontent () {

IkiWiki/Plugin/remove.pm

@@ -54,6 +54,26 @@ sub check_canremove ($$$) {
 			error("renaming of attachments is not allowed");
 		}
 	}
+
+	my $canremove;
+	IkiWiki::run_hooks(canremove => sub {
+		return if defined $canremove;
+		my $ret=shift->($page, $q, $session);
+		if (defined $ret) {
+			if ($ret eq "") {
+				$canremove=1;
+			}
+			elsif (ref $ret eq 'CODE') {
+				$ret->();
+				$canremove=0;
+			}
+			elsif (defined $ret) {
+				error($ret);
+				$canremove=0;
+			}
+		}
+	});
+	return $canremove;
 }
 
 sub formbuilder_setup (@) {

doc/plugins/write.mdwn

@@ -321,6 +321,14 @@ This hook should avoid directly redirecting the user to a signin page,
 since it's sometimes used to test to see which pages in a set of pages a
 user can edit.
 
+### canremove
+
+	hook(type => "canremove", id => "foo", call => \&canremove);
+
+This hook can be used to implement arbitrary access methods to control when
+a page can be removed using the web interface (commits from revision control
+bypass it). It works exactly like the `canedit` hook.
+
 ### editcontent
 
 	hook(type => "editcontent", id => "foo", call => \&editcontent);