feat: let a site choose which suffix the plugin treats as Mews

pelican-mews/pelican/plugins/mews/mews.py

@@ -47,7 +47,13 @@ LOGGER = logging.getLogger(__name__)
 
 CSS_NAME = "mews-0.1.css"
 DEFAULT_CSS_DIR = "css"
-XHTML_SUFFIX = ".xhtml"
+# Which files Pelican writes are Mews pages. The default keeps the plugin off
+# everything else, so it can run on a site that also produces ordinary HTML.
+# A site that is Mews throughout wants ".html" instead: servers send .xhtml as
+# application/xhtml+xml, which makes a browser parse as XML and fail hard on a
+# small markup error, and section 7.1 asks for text/html precisely to avoid
+# that. Set MEWS_SUFFIX to choose.
+DEFAULT_SUFFIX = ".xhtml"
 
 ALLOWLIST = parse_allowlist(
     files(__package__).joinpath("dtd", "mews.dtd").read_text(encoding="utf-8")
@@ -67,6 +73,12 @@ def _on_initialized(pelican) -> None:
         overrides.append(templates)
 
 
+def _suffix() -> str:
+    """Return the file extension a Mews page is written under, with its dot."""
+    suffix = str(_settings.get("MEWS_SUFFIX", DEFAULT_SUFFIX)).strip()
+    return suffix if suffix.startswith(".") else f".{suffix}"
+
+
 def _on_generator_init(generator) -> None:
     css_dir = generator.settings.get("MEWS_CSS_DIR", DEFAULT_CSS_DIR)
     generator.env.globals["MEWS_CSS"] = f"{css_dir}/{CSS_NAME}"
@@ -74,7 +86,7 @@ def _on_generator_init(generator) -> None:
 
 def _on_content_written(path, **_) -> None:
     file = Path(path)
-    if file.suffix != XHTML_SUFFIX:
+    if file.suffix != _suffix():
         return
     try:
         tree, doctype = parse_page(file.read_bytes())