From 6ea01b6e99ca7e47ba5b949d5ea07a186f53de3b Mon Sep 17 00:00:00 2001
From: Davo Smith <git@davosmith.co.uk>
Date: Thu, 30 Apr 2020 10:53:58 +0100
Subject: [PATCH] MDL-68564 outputrenderers: extend before_footer hook to allow
 output

---
 lib/outputrenderers.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index 74e7c807777..4f8de591efc 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -1385,15 +1385,20 @@ class core_renderer extends renderer_base {
     public function footer() {
         global $CFG, $DB;
 
+        $output = '';
+
         // Give plugins an opportunity to touch the page before JS is finalized.
         $pluginswithfunction = get_plugins_with_function('before_footer', 'lib.php');
         foreach ($pluginswithfunction as $plugins) {
             foreach ($plugins as $function) {
-                $function();
+                $extrafooter = $function();
+                if (is_string($extrafooter)) {
+                    $output .= $extrafooter;
+                }
             }
         }
 
-        $output = $this->container_end_all(true);
+        $output .= $this->container_end_all(true);
 
         $footer = $this->opencontainers->pop('header/footer');