From 04f82f56695aaab4a8ba74df288d4b35533a3e31 Mon Sep 17 00:00:00 2001
From: Damyon Wiese <damyon@moodle.com>
Date: Mon, 8 May 2017 16:14:01 +0800
Subject: [PATCH] MDL-58836 auth: Improve backwards compatibility

Auth plugins with custom signup forms may not be using renderables / renderers - or
even if they are they may return a renderable that can only be rendered with the renderer from the auth
plugin.

This change checks if the signup form is a renderable - if so try the plugin renderer or fall back on the general renderer.
Otherwise call display() from the mform which is the previous way of rendering an mform.
---
 auth/classes/output/login.php |  2 +-
 login/signup.php              | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/auth/classes/output/login.php b/auth/classes/output/login.php
index 5b924bb467b..2a507bd3af2 100644
--- a/auth/classes/output/login.php
+++ b/auth/classes/output/login.php
@@ -143,7 +143,7 @@ class login implements renderable, templatable {
         $data->error = $this->error;
         $data->forgotpasswordurl = $this->forgotpasswordurl->out(false);
         $data->hasidentityproviders = !empty($this->identityproviders);
-        $data->hasinstructions = !empty($this->instructions);
+        $data->hasinstructions = !empty($this->instructions) || $this->cansignup;
         $data->identityproviders = $identityproviders;
         list($data->instructions, $data->instructionsformat) = external_format_text($this->instructions, FORMAT_MOODLE,
             context_system::instance()->id);
diff --git a/login/signup.php b/login/signup.php
index e14518006cd..dc6774dd0ee 100644
--- a/login/signup.php
+++ b/login/signup.php
@@ -97,5 +97,17 @@ $PAGE->set_heading($SITE->fullname);
 
 echo $OUTPUT->header();
 
-echo $OUTPUT->render($mform_signup);
+if ($mform_signup instanceof renderable) {
+    // Try and use the renderer from the auth plugin if it exists.
+    try {
+        $renderer = $PAGE->get_renderer('auth_' . $authplugin->authtype);
+    } catch (coding_exception $ce) {
+        // Fall back on the general renderer.
+        $renderer = $OUTPUT;
+    }
+    echo $renderer->render($mform_signup);
+} else {
+    // Fall back for auth plugins not using renderables.
+    $mform_signup->display();
+}
 echo $OUTPUT->footer();