From c03fd66aeb8a6f10290381a76db0867fabe881e6 Mon Sep 17 00:00:00 2001
From: Luke Towers <github@luketowers.ca>
Date: Fri, 5 Jun 2020 16:01:22 -0600
Subject: [PATCH] Support new onUpload() AJAX handler for uploads instead of
 postback takeovers.

Fixes #5104. Refs: https://github.com/octobercms/october/commit/4f7e2995c72298c522a27bf162f8f5e7316d9417
---
 modules/cms/widgets/AssetList.php                    | 10 +++++-----
 modules/cms/widgets/assetlist/assets/js/assetlist.js |  4 ++++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/modules/cms/widgets/AssetList.php b/modules/cms/widgets/AssetList.php
index 3dda5d1b3..a37643560 100644
--- a/modules/cms/widgets/AssetList.php
+++ b/modules/cms/widgets/AssetList.php
@@ -57,8 +57,6 @@ class AssetList extends WidgetBase
         parent::__construct($controller, []);
 
         $this->bindToController();
-
-        $this->checkUploadPostback();
     }
 
     /**
@@ -622,10 +620,12 @@ class AssetList extends WidgetBase
     }
 
     /**
-     * Checks the current request to see if it is a postback containing a file upload
-     * for this particular widget.
+     * Process file uploads submitted via AJAX
+     *
+     * @return void
+     * @throws ApplicationException If the file "file_data" wasn't detected in the request or if the file failed to pass validation / security checks
      */
-    protected function checkUploadPostback()
+    public function onUpload()
     {
         $fileName = null;
 
diff --git a/modules/cms/widgets/assetlist/assets/js/assetlist.js b/modules/cms/widgets/assetlist/assets/js/assetlist.js
index f430c669c..4fb3d41cc 100644
--- a/modules/cms/widgets/assetlist/assets/js/assetlist.js
+++ b/modules/cms/widgets/assetlist/assets/js/assetlist.js
@@ -83,6 +83,9 @@
     }
 
     AssetList.prototype.onUploadFail = function(file, message) {
+        if (file.xhr.status === 413) {
+            message = 'Server rejected the file because it was too large, try increasing post_max_size';
+        }
         if (!message) {
             message = 'Error uploading file'
         }
@@ -170,6 +173,7 @@
             $.each(self.$form.serializeArray(), function (index, field) {
                 formData.append(field.name, field.value)
             })
+            xhr.setRequestHeader('X-OCTOBER-REQUEST-HANDLER', self.alias + '::onUpload')
             self.onUploadStart()
         })
     }