Fallback generated previews without ties

apps/theme_lab/app.py

@@ -13,6 +13,7 @@ import threading
 import uuid
 from pathlib import Path
 from typing import Literal
+from xml.etree import ElementTree as ET
 
 from fastapi import FastAPI, HTTPException, Query
 from fastapi.responses import FileResponse
@@ -382,11 +383,32 @@ def has_python_verovio_renderer() -> bool:
     return True
 
 
-def render_musicxml_with_python_verovio(musicxml_path: Path, svg_path: Path) -> Path | None:
+def musicxml_without_ties(musicxml_data: str) -> str | None:
+    try:
+        root = ET.fromstring(musicxml_data)
+    except ET.ParseError:
+        return None
+    for note in root.findall(".//note"):
+        for tie in list(note.findall("tie")):
+            note.remove(tie)
+        notations = note.find("notations")
+        if notations is None:
+            continue
+        for tied in list(notations.findall("tied")):
+            notations.remove(tied)
+        if len(notations) == 0:
+            note.remove(notations)
+    ET.indent(root)
+    return ET.tostring(root, encoding="unicode", short_empty_elements=True)
+
+
+def render_musicxml_with_python_verovio(musicxml_path: Path, svg_path: Path, *, strip_ties: bool = False) -> Path | None:
     try:
         import verovio
 
         musicxml_data = musicxml_path.read_text(encoding="utf-8")
+        if strip_ties:
+            musicxml_data = musicxml_without_ties(musicxml_data) or musicxml_data
         toolkit = verovio.toolkit()
         toolkit.setOptions({"scale": 42})
         svg = toolkit.renderData(musicxml_data, {}) if hasattr(toolkit, "renderData") else ""
@@ -406,6 +428,9 @@ def render_musicxml_with_python_verovio(musicxml_path: Path, svg_path: Path) ->
 def render_musicxml_to_svg(musicxml_path: Path) -> Path | None:
     svg_path = musicxml_path.with_suffix(".svg")
     python_svg = render_musicxml_with_python_verovio(musicxml_path, svg_path)
+    if python_svg is not None:
+        return python_svg
+    python_svg = render_musicxml_with_python_verovio(musicxml_path, svg_path, strip_ties=True)
     if python_svg is not None:
         return python_svg
     verovio = shutil.which("verovio")