From c8f0c59e53c03e105b92dc8612ac69d2421b612a Mon Sep 17 00:00:00 2001
From: Kyle M Hall <kyle@bywatersolutions.com>
Date: Tue, 23 Mar 2021 16:07:20 +0000
Subject: [PATCH] Bug 28026: Add call_recursive() as a supliment for call()

The method call() is not sufficient for all plugin hook types. It's
possible that more than one plugin will be installed that wants to
return the arguaments passed in an updated form.  These transformation
plugins need to work recursively rather than independantly.

This patch adss a `call_recursive()` method that takes the output of
the first plugin and uses it as the input for the next plugin and so
on. This allowes each plugin to see the current version of the arguament
list and modify it as necessary.

Test plan
1/ Run the included tests - t/db_dependent/Koha/Plugins/Plugins.t

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
---
 Koha/Plugins.pm                       | 35 +++++++++++++++++++++++++++
 t/db_dependent/Koha/Plugins/Plugins.t | 32 +++++++++++++++++++++++-
 2 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/Koha/Plugins.pm b/Koha/Plugins.pm
index 36e6090415..bedd220b6f 100644
--- a/Koha/Plugins.pm
+++ b/Koha/Plugins.pm
@@ -82,6 +82,41 @@ sub call {
     return @responses;
 }
 
+=head2 call_recursive
+
+Calls a plugin method for all enabled plugins,
+passing the return value from the previous plugin
+to the next one.
+
+    @response = Koha::Plugins->call_recursive($method, @args)
+
+=cut
+
+sub call_recursive {
+    my ( $class, $method, @args ) = @_;
+
+    my @responses;
+    if ( C4::Context->config('enable_plugins') ) {
+
+        my @plugins = $class->new( { enable_plugins => 1 } )->GetPlugins( { method => $method } );
+        @plugins = grep { $_->can($method) } @plugins;
+
+        foreach my $plugin (@plugins) {
+            my @response = eval { $plugin->$method(@args) };
+
+            if ($@) {
+                warn sprintf( "Plugin error (%s): %s", $plugin->get_metadata->{name}, $@ );
+                next;
+            } else {
+                @args = @response;
+            }
+        }
+
+    }
+
+    return @args;
+}
+
 =head2 GetPlugins
 
 This will return a list of all available plugins, optionally limited by
diff --git a/t/db_dependent/Koha/Plugins/Plugins.t b/t/db_dependent/Koha/Plugins/Plugins.t
index f49bd252fc..2480d99a41 100755
--- a/t/db_dependent/Koha/Plugins/Plugins.t
+++ b/t/db_dependent/Koha/Plugins/Plugins.t
@@ -25,7 +25,7 @@ use File::Temp qw( tempdir tempfile );
 use FindBin qw($Bin);
 use Module::Load::Conditional qw(can_load);
 use Test::MockModule;
-use Test::More tests => 53;
+use Test::More tests => 54;
 
 use C4::Context;
 use Koha::Database;
@@ -78,6 +78,36 @@ subtest 'call() tests' => sub {
     $schema->storage->txn_rollback;
 };
 
+subtest 'call_recursive() tests' => sub {
+    plan tests => 6;
+
+    $schema->storage->txn_begin;
+    # Temporarily remove any installed plugins data
+    Koha::Plugins::Methods->delete;
+
+    t::lib::Mocks::mock_config('enable_plugins', 1);
+    my $plugins = Koha::Plugins->new({ enable_plugins => 1 });
+    my @plugins = $plugins->InstallPlugins;
+    foreach my $plugin (@plugins) {
+        $plugin->enable();
+    }
+
+    my (@responses) = Koha::Plugins->call_recursive('item_barcode_transform', 1);
+    is( scalar @responses, 1, "Got back one element" );
+    is( $responses[0], 4, "Got expected response" );
+
+    (@responses) = Koha::Plugins->call_recursive('item_barcode_transform', 'abcd');
+    is( scalar @responses, 1, "Got back one element" );
+    is( $responses[0], 'abcd', "Got expected response" );
+
+    t::lib::Mocks::mock_config('enable_plugins', 0);
+    (@responses) = Koha::Plugins->call_recursive('item_barcode_transform', 1);
+    is( scalar @responses, 1, "Got back one element" );
+    is( $responses[0], 1, "call_recursive should return the original arguments if plugins are disabled" );
+
+    $schema->storage->txn_rollback;
+};
+
 subtest 'GetPlugins() tests' => sub {
 
     plan tests => 2;
-- 
2.30.1 (Apple Git-130)