From 4dd949b10ef3cfbdffdc28edf0e51a077bf38c68 Mon Sep 17 00:00:00 2001
From: Albert Gasset <albert.gasset@moodle.com>
Date: Thu, 17 Oct 2024 12:29:27 +0200
Subject: [PATCH] MOBILE-4616 database: Fix processing of templates

Some elements of templates were being removed, like <tr> or <li>.
---
 src/core/services/utils/dom.ts        | 30 +++++++++++++++------------
 src/core/singletons/text.ts           |  1 +
 src/core/utils/create-html-element.ts |  1 +
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/src/core/services/utils/dom.ts b/src/core/services/utils/dom.ts
index 924ef2b8c..165c6595b 100644
--- a/src/core/services/utils/dom.ts
+++ b/src/core/services/utils/dom.ts
@@ -262,23 +262,27 @@ export class CoreDomUtilsProvider {
      * @returns Fixed HTML text.
      */
     fixHtml(html: string): string {
-        return CoreText.processHTML(html, (element) => {
-            // eslint-disable-next-line no-control-regex
-            const attrNameRegExp = /[^\x00-\x20\x7F-\x9F"'>/=]+/;
-            const fixElement = (element: Element): void => {
-                // Remove attributes with an invalid name.
-                Array.from(element.attributes).forEach((attr) => {
-                    if (!attrNameRegExp.test(attr.name)) {
-                        element.removeAttributeNode(attr);
-                    }
-                });
+        // We can't use CoreText.processHTML because it removes elements that
+        // are not allowed as a child of <div>, like <li> or <tr>.
+        const template = document.createElement('template');
+        template.innerHTML = html;
 
-                Array.from(element.children).forEach(fixElement);
-            };
+        // eslint-disable-next-line no-control-regex
+        const attrNameRegExp = /[^\x00-\x20\x7F-\x9F"'>/=]+/;
+        const fixElement = (element: Element): void => {
+            // Remove attributes with an invalid name.
+            Array.from(element.attributes).forEach((attr) => {
+                if (!attrNameRegExp.test(attr.name)) {
+                    element.removeAttributeNode(attr);
+                }
+            });
 
             Array.from(element.children).forEach(fixElement);
-        });
+        };
 
+         Array.from(template.content.children).forEach(fixElement);
+
+         return template.innerHTML;
     }
 
     /**
diff --git a/src/core/singletons/text.ts b/src/core/singletons/text.ts
index 482ce044a..19f0c49fc 100644
--- a/src/core/singletons/text.ts
+++ b/src/core/singletons/text.ts
@@ -418,6 +418,7 @@ export class CoreText {
 
     /**
      * Process HTML string.
+     * Warning: Top-level elements that are not allowed as a child of <div> (like <tr> or <li>) will be removed.
      *
      * @param text HTML string.
      * @param process Method to process the HTML.
diff --git a/src/core/utils/create-html-element.ts b/src/core/utils/create-html-element.ts
index 076d6bbc4..ebdb9a2ff 100644
--- a/src/core/utils/create-html-element.ts
+++ b/src/core/utils/create-html-element.ts
@@ -14,6 +14,7 @@
 
 /**
  * Convert some HTML as text into an HTMLElement. This HTML is put inside a div.
+ * Warning: Top-level elements that are not allowed as a child of <div> (like <tr> or <li>) will be removed.
  *
  * @param html Text to convert.
  * @returns Element.