Follow up to #1868: prevent escaping of HTML inside message content strings

Author: cpsievert

shiny/ui/_chat.py

@@ -18,7 +18,7 @@
 )
 from weakref import WeakValueDictionary
 
-from htmltools import HTML, Tag, TagAttrValue, TagChild, TagList, css
+from htmltools import HTML, Tag, TagAttrValue, TagChild, TagList, css, RenderedHTML
 
 from .. import _utils, reactive
 from .._deprecated import warn_deprecated
@@ -1450,7 +1450,12 @@ def chat_ui(
             if "role" in x:
                 role = x["role"]
 
-        ui = TagList(content).render()
+        # `content` is most likely a string, so avoid overhead in that case
+        # (it's also important that we *don't escape HTML* here).
+        if isinstance(content, str):
+            ui: RenderedHTML = {"html": content, "dependencies": []}
+        else:
+            ui = TagList(content).render()
 
         if role == "user":
             tag_name = "shiny-user-message"

shiny/ui/_markdown_stream.py

@@ -1,7 +1,7 @@
 from contextlib import asynccontextmanager
 from typing import AsyncIterable, Iterable, Literal, Union
 
-from htmltools import TagChild, TagList, css
+from htmltools import RenderedHTML, TagChild, TagList, css
 
 from .. import _utils, reactive
 from .._deprecated import warn_deprecated
@@ -353,7 +353,13 @@ def output_markdown_stream(
     height
         The height of the UI element.
     """
-    ui = TagList(content).render()
+
+    # `content` is most likely a string, so avoid overhead in that case
+    # (it's also important that we *don't escape HTML* here).
+    if isinstance(content, str):
+        ui: RenderedHTML = {"html": content, "dependencies": []}
+    else:
+        ui = TagList(content).render()
 
     return Tag(
         "shiny-markdown-stream",