Bug 1352913 - Extensions must register for template_before_process()

We can skip a lot of method calls if extensions must declare what
templates they act on.

2 files changed, 46 insertions, 21 deletions

diff --git a/Bugzilla/Hook.pm b/Bugzilla/Hook.pm
index 00bd316ab..e28c01a40 100644
--- a/Bugzilla/Hook.pm
+++ b/Bugzilla/Hook.pm
@@ -11,18 +11,42 @@ use 5.10.1;
 use strict;
 use warnings;
 
+use Scalar::Util qw(blessed);
+
 sub process {
-    my ($name, $args) = @_;
+    my ($name, $args, $extensions) = @_;
+
+    $extensions //= Bugzilla->extensions;
+
+    my $hook_stack = Bugzilla->request_cache->{hook_stack} ||= [];
+    push @$hook_stack, $name;
+
+    foreach my $extension (@$extensions) {
+        if (my $hook = $extension->can($name)) {
+            $hook->($extension, $args);
+        }
+    }
 
-    _entering($name);
+    pop @$hook_stack;
+}
+
+sub collect_wants {
+    my ($name) = @_;
+    my %result;
 
     foreach my $extension (@{ Bugzilla->extensions }) {
-        if ($extension->can($name)) {
-            $extension->$name($args);
+        my $hook = $extension->can($name);
+        if ($hook) {
+            my $wants = $hook->($extension);
+            foreach my $want (keys %$wants) {
+                if ($wants->{$want}) {
+                    $result{ $want }{ blessed $extension } = 1;
+                }
+            }
         }
     }
 
-    _leaving($name);
+    return \%result;
 }
 
 sub in {
@@ -31,16 +55,6 @@ sub in {
     return $hook_name eq $currently_in ? 1 : 0;
 }
 
-sub _entering {
-    my ($hook_name) = @_;
-    my $hook_stack = Bugzilla->request_cache->{hook_stack} ||= [];
-    push(@$hook_stack, $hook_name);
-}
-
-sub _leaving {
-    pop @{ Bugzilla->request_cache->{hook_stack} };
-}
-
 1;
 
 __END__
diff --git a/Bugzilla/Template/Context.pm b/Bugzilla/Template/Context.pm
index b81e32130..e78cd9806 100644
--- a/Bugzilla/Template/Context.pm
+++ b/Bugzilla/Template/Context.pm
@@ -69,13 +69,24 @@ sub stash {
     # template object for Throw*Error).
     #
     # Checking Bugzilla::Hook::in prevents infinite recursion on this hook.
-    if ($self->{bz_in_process} and $name =~ /\./
-        and !grep($_ eq $name, @$pre_process)
-        and !Bugzilla::Hook::in('template_before_process'))
+
+    if (    $self->{bz_in_process}
+        and $name =~ /\./
+        and !grep( $_ eq $name, @$pre_process )
+        and !Bugzilla::Hook::in('template_before_process') )
     {
-        Bugzilla::Hook::process("template_before_process",
-                                { vars => $stash, context => $self,
-                                  file => $name });
+        state $WANT = Bugzilla::Hook::collect_wants('template_before_process_wants');
+        if ( $WANT->{$name} ) {
+            my @extensions = grep { $WANT->{$name}{ blessed $_ } } @{ Bugzilla->extensions };
+            Bugzilla::Hook::process(
+                "template_before_process" => {
+                    vars    => $stash,
+                    context => $self,
+                    file    => $name
+                },
+                \@extensions
+            ) if @extensions;
+        }
     }
 
     # This prevents other calls to stash() that might somehow happen