From c925fae1801c04fce4e3e9b81cb380c5779fa4b5 Mon Sep 17 00:00:00 2001
From: Loz Calver <kinglozzer@gmail.com>
Date: Wed, 2 Nov 2022 10:02:42 +0000
Subject: [PATCH 1/3] NEW: Add onBeforeRender extension hook to Form

---
 src/Forms/Form.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index c816c53f3..4d46f1fdb 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -1552,10 +1552,13 @@ class Form extends ViewableData implements HasRequestHandler
             HTTPCacheControlMiddleware::singleton()->disableCache();
         }
 
-        $return = $this->renderWith($this->getTemplates());
+        $context = $this;
+        $this->extend('onBeforeRender', $context);
+
+        $return = $context->renderWith($this->getTemplates());
 
         // Now that we're rendered, clear message
-        $this->clearMessage();
+        $context->clearMessage();
 
         return $return;
     }

From e2cb683f148373971bd1654c16e536b602277883 Mon Sep 17 00:00:00 2001
From: Loz Calver <kinglozzer@gmail.com>
Date: Wed, 2 Nov 2022 10:06:23 +0000
Subject: [PATCH 2/3] FIX: Stop FormField onBeforeRenderHolder extension result
 being overridden

---
 src/Forms/FormField.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Forms/FormField.php b/src/Forms/FormField.php
index 8632cfedf..760c012c6 100644
--- a/src/Forms/FormField.php
+++ b/src/Forms/FormField.php
@@ -959,7 +959,7 @@ class FormField extends RequestHandler
         $this->extend('onBeforeRenderHolder', $context, $properties);
 
         if (count($properties ?? [])) {
-            $context = $this->customise($properties);
+            $context = $context->customise($properties);
         }
 
         return $context->renderWith($this->getFieldHolderTemplates());

From 7f8f5afc9191f6a97e9e097fa44afd059bc68b23 Mon Sep 17 00:00:00 2001
From: Loz Calver <kinglozzer@gmail.com>
Date: Wed, 2 Nov 2022 11:57:57 +0000
Subject: [PATCH 3/3] Ensure forms/fields overridden by onBeforeRender() can
 override templates

---
 src/Forms/Form.php      | 2 +-
 src/Forms/FormField.php | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index 4d46f1fdb..9e0f852db 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -1555,7 +1555,7 @@ class Form extends ViewableData implements HasRequestHandler
         $context = $this;
         $this->extend('onBeforeRender', $context);
 
-        $return = $context->renderWith($this->getTemplates());
+        $return = $context->renderWith($context->getTemplates());
 
         // Now that we're rendered, clear message
         $context->clearMessage();
diff --git a/src/Forms/FormField.php b/src/Forms/FormField.php
index 760c012c6..bd24b8392 100644
--- a/src/Forms/FormField.php
+++ b/src/Forms/FormField.php
@@ -927,7 +927,7 @@ class FormField extends RequestHandler
             $context = $context->customise($properties);
         }
 
-        $result = $context->renderWith($this->getTemplates());
+        $result = $context->renderWith($context->getTemplates());
 
         // Trim whitespace from the result, so that trailing newlines are suppressed. Works for strings and HTMLText values
         if (is_string($result)) {
@@ -962,7 +962,7 @@ class FormField extends RequestHandler
             $context = $context->customise($properties);
         }
 
-        return $context->renderWith($this->getFieldHolderTemplates());
+        return $context->renderWith($context->getFieldHolderTemplates());
     }
 
     /**